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Leptin obesity mice experiment – A leptin dose-response study in obese (ob/ob) and lean (+/?) mice

In vitro studies have shown that leptin induces insulin resistance in HepG2 cells 37 , a hepatocellular carcinoma cell line, and rat adipocytes Studies have shown that having excess weight increases susceptibility to diabetes, cardiovascular disease, high blood pressure and stroke, as well as certain forms of cancer.

Matthew Cox
Monday, March 22, 2021
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  • Enzyme activity was only measured in tissue from three treatment groups per genotype.

  • Clin Infect Dis 22 : —

  • Leptin was a gift from ZymoGenetics Corp.

  • Sigma Chemical Co.

Materials and Methods

Google Scholar PubMed. Article Navigation. Weight reducing effects of the plasma protein encoded by the obese gene.

  • Advanced search. The body weight of KK-A y mice usually reaches approximately 45 g at two months of age, which is characterized as moderate obesity.

  • Both the pellet P and the supernatant s were analyzed for receptor. The significance is for a genotype effect on catecholamine concentration determined by two-way ANOVA in which genotype and leptin dose were independent variables.

  • J Mol Endocrinol ; 36 : — Obese gene in the mouse.

  • Repeated measurements of temperature caused a progressive increase in temperature of all animals.

Erin Rodgers. London: Boca Raton, Fla. Google Preview. Show results from All journals This journal. The cafeteria diet as a tool for studies of thermogenesis.

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The limitation on transport may be due either to binding proteins in the circulation 16 or to a specific transport protein experiment Daily food intakes lsptin lean and obese mice. We did not measure any cytokines other than leptin in this study due to a limitation in the amount of serum available. The small amount of protein needed to initiate these changes suggests that they are all primary physiological responses to leptin. Issue Section:. Ruth B. Thus, a greater input than output of energy will result in increased fat storage.

Table 5 The effect of leptin infusion on serum hormone and glucose levels in lean and obese mice. Inguinal mg. Alcohol Obestiy Exp Res 11 : — The design of this experiment did not allow us to determine which responses in the mice were direct effects of leptin and which were secondary to the state of negative energy balance induced by leptin.

Materials and Methods

Superscripts leptin obesity mice experiment a significant difference between treatment groups within the obese genotype on leptiin fourth day of infusion. Two-way ANOVA indicated a significant genotype effect on 5-HT and 5-hydroxyinoleacetic acid 5-HIAA concentrations in the hypothalamus and brain stem, with both compounds being present at higher concentrations in obese than in lean animals. The weights of different adipose depots are shown in Table 1.

  • Cell metabolism.

  • Leptin expression was measured by Northern blot analysis and expressed as a ratio to 28S ribosomal RNA.

  • Depending on the target in question, there are a number of models that can be applied. International journal of body composition research.

  • The effect of leptin infusion on serum hormone and glucose levels in lean and obese mice.

Superscripts indicate significant differences in levels of expression in fat from obese mice. Paquot NSchneiter PJequier ETappy L Effects of glucocorticoids and sympathomimetic agents on basal and insulin-stimulated glucose metabolism. Citrate synthase. Before leptin infusion, the temperatures of all obese mice were significantly lower than those of lean animals. It promotes a-melanocyte-stimulating hormone a-MSHwhich acts as an appetite suppressant.

Alcohol Clin Exp Res 11 : — There was peptin significant effect of leptin or of an interaction between genotype and leptin on any of the parameters; therefore, the means for the two genotypes are the average from all animals in the experiment. Therefore, Table 7 summarizes the effect of genotype on the concentrations of monoamines within the three brain regions. There was no statistically significant effect of any dose of leptin on the weight of any of the organs measured in either obese or lean mice. Endocrinology : — Nature :

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These doses also increased brown adipose tissue experiment protein expression. One mouse was found dead in its cage CR group. However, it is largely unknown if leptin has a role in the control of weight regain after RYGB. These observations suggest that reduction of circulating leptin is a major signal responsible for the metabolic and behavioral responses that lead to regain of lost weight. One week after release from caloric restriction, CR group mice regained most of their lean mass AL:

  • Nocturnal rise of leptin in lean, obese, and non-insulin-dependent diabetes mellitus subjects. Weekly food intake and weekly change in fat and lean mass were used in the calculation.

  • Volume

  • International Journal of Obesity

  • In contrast, wild type mice increase food intake when ambient temperature is decreased and reduce energy intake under thermoneutral conditions. Endocrinology ; : —

N Engl J Med : — Published : 28 October Editorial is judgement in advance of the facts. Measured TEE and beam breaks were assigned to bins of beam breaks.

Under normal conditions, leptin produced from adipose tissue signals acts via the leptin receptor to reduce food intake. Food intake and body lepttin was monitored daily using the BioDaq cage system. Daniel Riquier. There was no significant effect of leptin or of an interaction between genotype and leptin on any of the parameters; therefore, the means for the two genotypes are the average from all animals in the experiment. Sigma Chemical Co. Ann Surg ; : —

MeSH terms

As there is a experiiment gradient between serum and cerebrospinal fluid leptin 1415it has been hypothesized that a rate-limited transport system prevents peripheral leptin from activating the central receptor that suppresses food intake. Peptides 17 : — Liver tissue was frozen for subsequent analysis of glycogen by the method of Lo et al.

  • Liraglutide has been tested for its ability to reduce body weight, as well as to prevent or delay the onset of diabetes in UCD-T2DM rats 0.

  • VMH neurons under the magnifying glass. We did not measure any cytokines other than leptin in this study due to a limitation in the amount of serum available.

  • This is an open access article distributed under the terms of the Creative Commons Attribution Licensewhich permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Materials and Methods.

  • Thus, even if the obese Zucker rat is an animal model with several similarities to human obesityy and metabolic syndrome, a discrepancy exists with respect to the pharmacological effect of sibutramine. It was found that in lean Zucker rats, which are not homozygous for the fa mutation, sibutramine resulted in a significant reduction in food intake compared to the vehicle.

Health Canada 2. The liver, hypothalamus, brown fat, and gonadal fat were snap-frozen. Hexokinse and phosphofructokinase. In lean mice, leptin has minimal effects on food intake, but causes the loss of body fat, presumably due to a leptin-induced increase in energy expenditure Therefore, it is possible that the effect on body temperature was also partially due to a leptin-induced increase in concentrations of inflammatory cytokines. So far, no definitive studies have shown that leptin will cause weight loss in all individuals [8] indicating that obesity is likely to not only be caused by biological factors.

Nature : — Gonadal fat leptin mRNA expression is shown in Fig. Leptin acts within a feedback loop to regulate body weight. Smith, Erin Rodgers, Jeffrey J.

Introduction

Gastric bypass model in the obese rat to study metabolic mechanisms of weight loss. You experimwnt also search for this author in PubMed Google Scholar. Polygenic models Diet-induced obese rats and mice Monogenic animal models of obesity are useful because the obesity and adiposity they develop is often severe, resulting in a distinct phenotype. These conclusions may help to predict efficacy of RYGB surgery before the surgery, and explain the weight regain after surgery. Monogenic models KK-A y mice The inbred mouse strain KK was established in Japan and is a mouse model with peripheral insulin sensitivity and glucose intolerance 4.

Correspondence to Mads Tang-Christensen. Science : — Rectal core body temperature was measured every 3 h ldptin 24 h using a Thermalert Monitoring Thermometer starting at For another class of pharmacological agents, the GLP-1 receptor agonists, the obese Zucker rat has been shown to be more predictive of the human situation with respect to regulation of appetite and body weight. Fat apoptosis through targeted activation of caspase 8: a new mouse model of inducible and reversible lipoatrophy.

Exendin-4 decelerates food intake, weight gain, and fat deposition in Zucker rats. Total g. Compensatory pathways could develop as a result of congenital leptin deficiency and this leads to an important caveat that the responses to the weight perturbations reported here may be unique to these animals. This study suggests that the intact function of leptin circuitry may be required for RYGB effects. Upon arrival, mice were group-housed 3 mice per cage with ad libitum access to chow and water for a two week acclimation period.

Increased obese mRNA expression in omental fat cells from massively obese humans. Plasma assays Blood was collected on ice using heparinized tubes Fisherbrand. Below thermoneutrality, changes in activity do not drive changes in total daily energy expenditure between groups of mice.

In addition to mice experiment stigmas, there are significant health risks that come with being ex;eriment. For example, many athletes people with a low percentage of body fatdo not have their periods. After pump placement, measurements of daily food intake and body weight were continued, and rectal temperatures were measured after 2 and 4 days of infusion. This explanation is true but incomplete.

Ikeda H. Ann Surg ; : — Diabetes 46 : obexity Early life stress affects the HPT axis response in a sexually dimorphic manner. Long-Evans and Sprague-Dawley rats exhibit divergent responses to refeeding after caloric restriction. A high-fat and high-sucrose diet has been reported to result in a similar effect on body weight, abdominal fat, hyperinsulinemia and hyperglycemia as a high-fat-only diet in mice 52 Nonshivering thermogenesis in the rat.

To obtain the best experience, we recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer. The energy intake after liraglutide treatment was significantly reduced compared to vehicle-treated animals. Stephen M.

Long-term persistence of adaptive thermogenesis in subjects who have maintained a reduced body weight. However, the extent to which the different diets are comparable with respect to the secondary outcomes of obesity medications, such as plasma lipids and glucose tolerance, needs to be further explored. Fat redistribution following suction lipectomy: defense of body fat and patterns of restoration. Role of fat amount and type in ameliorating diet-induced obesity: insights at the level of hypothalamic arcuate nucleus leptin receptor, neuropeptide Y and pro-opiomelanocortin mRNA expression.

  • Seattle, WA. Large cohort—study design Study design is outlined in Fig 1.

  • The lipostatic theory was supported by an experiment carried out by Hervey in [3].

  • Fig 8.

  • In a the obese mouse lost weight suggesting a circulating ob hormonein b the normal mouse lost weight suggesting that the db component does not circulate, and the ob factor is overexpressed by the db mouseand in c the ob mouse lost weight suggesting that the ob factor was produced by the db mouse and circulates. To provide overall tests of the dosage effect of leptin on each variable, a profile analysis was effected by testing the appropriate contrasts corresponding to the parallel, coincident, and level profiles hypotheses for days 4—7 of infusion after the mice had recovered from the surgery.

  • Hypothalamic and genetic obesity in experimental animals: an autonomic and endocrine hypothesis.

In addition, there was no effect of leptin on basal serum insulin concentrations in lean mice, and noninsulin-dependent diabetes is associated with both elevated leptin and insulin levels 40 Repeated measurements of temperature caused a progressive increase in temperature of all animals. There are a number of possible explanations for the discrepancy. Clin Physiol 15 : — The failure of leptin to reverse this defect demonstrates that it is not a direct result of leptin deficiency and is not associated with the hyperphagia, hyperinsulinemia, or hypothermia. It is possible that leptin changes glucose-stimulated insulin release and insulin responsiveness, which would not have been detected in this experiment. Central infusion of leptin into dietary obese mice inhibits intake 32indicating that the resistance to peripheral leptin is caused by a failure to transport the protein to the hypothalamic long form, OB-Rb, receptor, which is responsible for the hypophagic effects of leptin

Emillson et al. The improvement cannot be entirely attributed to the reduction in food intake and body fat content of the mice, as Pellymounter et al. Article Contents Abstract. All mice were decapitated in the morning of day 7 of leptin infusion. Regulation of obese ob mRNA and plasma leptin levels in rhesus monkeys. In this experiment, the circulatory system of a rat with a lesion in the hypothalamus was surgically joined with the circulatory system of a normal rat.

MeSH terms

Mice were allowed to continue eating ad libitum for another 4 weeks. Thank you for visiting nature. Daily body weights of the mice are shown in Fig. Google Preview. Leptin reverses insulin resistance and diabetes mellitus in mice with congenital lipodystrophy.

Sensitivity to leptin and susceptibility to seizures of mice lacking neuropeptide Y. This protein, leptin, mice experiment the structure of a long chain helical cytokine 4 and is expressed in adipose tissue in proportion to adipocyte size 56. Reduced sensitivity compared with lean animals. Diet and exercise can result in a loss of both fat and muscle, whereas taking leptin results in fat loss. Erin Rodgers. Kidney mg. This would allow separation of physiological from potentially pharmacological responses.

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Ideally these studies would have been carried out under thermoneutral conditions expermient 35 ]. Uterus mg. Trophic action of leptin on hypothalamic neurons that regulate feeding. Total activity number of infrared beam breaks in X, Y, and Z axis was recorded in minute time intervals and a corresponding TEE was measured at the end of each interval. There was no significant effect of leptin or of an interaction between genotype and leptin on any of the parameters; therefore, the means for the two genotypes are the average from all animals in the experiment.

The weights of different adipose depots are shown in Table 1. Measured Experiment and beam breaks were assigned to bins of beam breaks. Decreased food intake does not completely account for adiposity reduction after ob protein infusion. Bouchard C, Tremblay A. To determine if energy expenditure was conserved at a given activity level in the groups, each group was sorted by day [—] and night [—] from lowest to highest activity [beam breaks] with contemporaneously measured TEE. The dramatic reduction in food intake on the first day of leptin infusion was partially due to surgery.

Body weight and fat content after RYGB. International journal of body composition research. Accepted : 18 October

Google Preview. This observation confirms the hypothesis leptin obesity mice experiment Levin et al. As previously mentioned, the leptin receptor is expressed in various tissue such as the muscles and the gut, but it is especially expressed in the ventromedial hypothalamus VHM. Select Format Select format. This could be related to amount of fat that is stored.

Decreased food intake does not completely account for adiposity reduction after ob protein infusion. Gennady N. Email alerts Article activity alert. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide. In contrast, the two highest doses of leptin caused a stable reduction in food intake and continuous weight loss in obese mice. If the change in liver composition had been directly mediated by leptin, a change in receptor number may have been expected as liver energy stores declined.

Superscripts leptin obesity mice experiment significant differences in levels of expression leotin fat from obese mice. Rectal temperatures of lean and obese mice measured twice before leptin infusion and twice during leptin infusion. This observation confirms the hypothesis of Levin et al. Two-way ANOVA indicated a significant genotype effect on 5-HT and 5-hydroxyinoleacetic acid 5-HIAA concentrations in the hypothalamus and brain stem, with both compounds being present at higher concentrations in obese than in lean animals.

  • Similarly, in humans, treatment with GLP-1 analogues leads to appetite reduction and weight loss 40 Beyond glucose lowering: Glucagon-like peptide-1 receptor agonists, body weight and the cardiovascular system.

  • Inan experiment was carried out to determine whether recombinant leptin could be used to treat obesity in a girl who was homozygous for the ob mutation.

  • Body weight was monitored for 39 wks with composition test at 3 wks, food intake at 6—7 wks, and EE at 8—9 wks post surgery.

  • Steven R. Physiol Behav 61 : —

  • We have found that this method of protein administration causes excessive, intermittent elevations of the serum leptin concentration

However, neuropeptide Y knockout mice are responsive to leptin 51indicating some redundancy in the mechanisms that mediate leptin-induced hypophagia. Early life stress affects the HPT axis response in a sexually dimorphic manner. Louis, MO and water. Spleen mg.

LoveLaurana J. N Eng J Med ; : — The inheritance of glucosuria expeirment the KK and AY mouse. Leptin had no effect on the concentrations of any other neurotransmitter measured in the three brain areas dissected. Animal models of Diabetes Frontiers in Research. Leptin rapidly suppresses insulin release from insulinoma cells, rat and human islets and, in vivo, in mice. Hambly et al.

J Clin Invest 99 : — Can J Physiol Pharmacol 56 : — After pump placement, measurements of daily food intake and body weight were continued, and rectal temperatures were measured after 2 and 4 days of infusion.

So far, no definitive studies have shown that leptin will cause weight loss in all individuals [8] indicating that obesity is likely to not only be caused by biological factors. What is Leptin? Srere PA Citrate synthase. Pancreas mg. This would allow separation of physiological from potentially pharmacological responses.

Experiment leptin had no significant effect mife the hepatic lipid or glycogen content of lean mice, these results also suggest that the metabolic effect is tissue specific, diverting nutrients from adipose tissue to other tissues that have a higher metabolic rate. Google Scholar Crossref. The effect of leptin infusion on serum hormone and glucose levels in lean and obese mice. The hypothalamus is a gland that regulates eating patterns, body temperature, and metabolism.

Association of central obesity with hepatocellular leptin obesity mice experiment in patients with chronic hepatitis B receiving antiviral therapy. Therefore, it is possible that the effect on body temperature was also partially due to a leptin-induced increase in concentrations of inflammatory cytokines. Despite the substantial change in liver composition and metabolism, there was no change in the level of expression of hepatic short form leptin receptors OB-Ra, OB-Rc, OB-Rd, and OB-Rfwhich have been shown to have signaling capability 33 Srere PA Citrate synthase.

  • Student t-tests 2-tailed were conducted to compare AL and CR groups. Effects of glucocorticoids and sympathomimetic agents on basal and insulin-stimulated glucose metabolism.

  • The function of leptin in nutrition, weight and physiology.

  • Google Scholar 41 Bode B. Stephen M.

It has been proposed that one of the leptin receptor subtypes, with a short intracellular domain, may function as a transport obesitty and regulate leptin uptake into the brain Select Format Select format. Citrate synthase was used as a general marker for oxidative capacity and was assayed as described by Srere Nutrition Reviews 11 Supplement FEBS Lett : 87 — Leptin had no effect on the concentrations of any other neurotransmitter measured in the three brain areas dissected.

Introduction Roux-en-Y gastric bypass surgery RYGB is among the most effective bariatric surgeries in producing sustained decrease in body weight and remission leptin obesity mice experiment type-2 diabetes. The Zucker rat is therefore considered a good animal model for this metabolic syndrome. One explanation for the lack of effect on body weight in the study by Irvin et al could be that exendin-4 was only given once daily. Raw data from food intake, body composition, body temperature, and body weight.

Liver short form leptin receptor detected by Western blot using a polyclonal antibody raised to the extracellular membrane portion of the receptor. Open in new tab Download slide. Finally, in vitro studies may not be representative of in vivo responses due to the absence of appropriate feedback systems, compensatory mechanisms, and secondary responses to leptin treatment.

Gastroenterology ; leptim — e This would allow separation of physiological from potentially pharmacological responses. In humans central obesity and cvd rodents with an intact leptin axis, energy expenditure is highly correlated with metabolic mass [ 6 ]. FollettAminata BojangKhrystyne N. Physiological response to long-term peripheral and central leptin infusion in lean and obese mice. Ruth B.

Toward a more complete and less controversial understanding of energy expenditure and its role in obesity pathogenesis. Physiol Behav 61 : — The current leptin obesity mice experiment is limited in the ability to look at genetic factors aside from leptin that can alter the response to caloric restriction since all the mice studied were the same strain. Obese humans and mice made obese by dietary means have elevated circulating concentrations of leptin but maintain a normal food intake 30 — Biological activity of EXf, a peptide analogue of exendin

Leptin as a Treatment of Obesity The administration of leptin acts differently from food restriction and exercise. These DIO mice exhibited a partial response to leptin therapy [6]. Materials and Methods. There was no effect of leptin on UCP expression in lean mice. Peptides 17 : —

Hypothalamic and genetic obesity central obesity and cvd experimental animals: an autonomic and endocrine hypothesis. The reduction was experiemnt percentage relative to the pretreatment level. Hexokinse and phosphofructokinase. These changes were small, and significance was due to the absence of variance in some of the treatment groups, but they may be representative of a shift in nutrient utilization from glucose to fatty acid oxidation, consistent with fatty acids being mobilized from adipose tissue.

  • Over the 9-week period following leptin obesity mice experiment release of CR mice to ad libitum feeding until the end of the study cumulative food intake calculated for each group was It has also become clear that the negative energy balance after RYGB does not result from an inability to increase energy intake.

  • Hexokinse and phosphofructokinase. Leptin acts within a feedback loop to regulate body weight.

  • Gastroenterology ; : —

  • Effects of chronic weight perturbation on energy homeostasis and brain structure in mice.

  • Depending on food intake and energy expenditure, the size of fat cells will vary. The significance is for a genotype effect on catecholamine concentration determined by two-way ANOVA in which genotype and leptin dose were independent variables.

Superscripts indicate significant differences experiment expression between groups of obese mice. Finally, in vitro studies may not be representative of in vivo responses due to the absence of appropriate feedback systems, compensatory mechanisms, and secondary responses to leptin treatment. In studies with mice, it was found that some strains became obese after being fed a high-fat diet diet-induced obese mice or DIO micewhereas some mice did not. Hexokinse and phosphofructokinase. Leptin was a gift from ZymoGenetics Corp.

However, neuropeptide Y knockout mice are responsive to leptin 51indicating some redundancy in the mechanisms that mediate leptin-induced hypophagia. Sleep deprivation by the flower pot technique and spatial reference memory. Superscripts indicate significant differences in levels of expression in fat from obese mice. Leptin levels in human and rodent: measurement of plasma leptin and ob RNA in obese and weight-reduced subjects. The concept of a biological factor in weight regulation is not new.

Hexokinse and phosphofructokinase. Leptin receptors have also been found on pancreatic b-cells, which produce insulin. If the change in liver composition had been directly mediated by leptin, a change in receptor number may have been expected as liver energy stores declined.

  • PloS one. However, a common argument against the monogenic models in general and the monogenic models deficient in the leptin system in particular is that they are not representative of the human pathogenesis of obesity.

  • A similar rate-limiting transport system appears to be present in humans, as leptin obesity mice experiment concentration gradient in leptin is maintained between blood and cerebrospinal fluid 14 The lipostatic theory proposed that there was product of fat metabolism that circulated in the blood and acted as a signal to the hypothalamus.

  • In parallel, AL mice gained body weight at a steady rate of approximately 0. A similar rate-limiting transport system appears to be present in humans, as a concentration gradient in leptin is maintained between blood and cerebrospinal fluid 14 ,

  • World Health Organization 3. Nat Med 2 : —

Diabetologia ; 9 : — For another class of pharmacological agents, the GLP-1 receptor agonists, the obese Zucker rat has been shown to be more predictive of the human situation with experiiment to regulation of appetite and body weight. The weight reduction was identical in mass g in the two groups. The mahoganoid mutation Mgrn1md improves insulin sensitivity in mice with mutations in the melanocortin signaling pathway independently of effects on adiposity. Several mice were excluded from the analysis. Methods Enzymol 13 : 3 — 5. Endocrine and metabolic effects of experimental obesity in man.

Heart mg. Seattle, WA. Serum immunoreactive-leptin concentrations in normal-weight and obese humans. In contrast, the two highest doses of leptin caused a stable reduction in food intake and continuous weight loss in obese mice. There were no significant differences within lean or obese genotypes on any other day. Latest Most Read Most Cited Hormonally regulated myogenic miR influences sex-specific differences in cancer-induced skeletal muscle defects. Stephen M.

In recent years, micd leptin obesity mice experiment of fructose in the development of adiposity and metabolic syndrome has received significant attention We have found that this method of protein administration causes excessive, intermittent elevations of the serum leptin concentration Download PDF. Effects of ambient temperature on adaptive thermogenesis during maintenance of reduced body weight in mice.

Sign In or Create an Account. Lower doses of leptn had no significant effect on food intake. A similar rate-limiting transport system appears leptin obesity mice experiment be present in humans, as a concentration gradient in leptin is maintained between blood and cerebrospinal fluid 14 N-3 long chain polyunsaturated fatty acids: a nutritional tool to prevent insulin resistance associated to type 2 diabetes and obesity? Inbred strains resulting from Japanese mice.

Central infusion of leptin into dietary obese mice inhibits intake 32indicating that the resistance to peripheral leptin is caused by a failure to transport the protein to the hypothalamic long form, OB-Rb, receptor, which is responsible for the hypophagic effects of leptin Skip Nav Destination Article Navigation. Cytoplasmic domain mutational analysis and evidence for receptor homo-oligomerization. The improvement cannot be entirely attributed to the reduction in food intake and body fat content of the mice, as Pellymounter et al. Emillson et al. Leptin was a gift from ZymoGenetics Corp. Clin Infect Dis 22 : —

In WT mice, serum insulin was increased by obesity five- to sixfold Figure 4asham. Hao, Z. Notably few cases of human obesity can be accounted for mutations in leptin or the leptin receptor Heart mg. However, recent findings in various rodent models have provided relatively little support for their critical roles in the effects of RYGB, 1011121314 although synergistic actions between these hormones and other factors have not been excluded. N-3 long chain polyunsaturated fatty acids: a nutritional tool to prevent insulin resistance associated to type 2 diabetes and obesity? The Zucker rat The Zucker rat is a commonly used obese rat model.

There was no effect of leptin treatment on receptor in lean or obese mice. There edperiment no effect of leptin on the temperatures of lean mice. It has been proposed that one of the leptin receptor subtypes, with a short intracellular domain, may function as a transport protein and regulate leptin uptake into the brain Liver glycogen mg. Sigma Chemical Co.

In addition, there was no ecperiment of leptin on basal serum insulin concentrations in lean mice, and noninsulin-dependent diabetes is associated with both elevated leptin and insulin leptin obesity mice experiment 40 Recombinant leptin exchanges between parabiosed mice but does not reach equilibrium. Smagin, Steven R. Google Scholar PubMed. The difference in these results and those reported previously 18 may be due to the short duration of this experiment, which involved only 7 days of leptin infusion, compared with the 5-day reproductive cycle of mice. Download all slides.

As leptin had no significant effect on the hepatic lipid or glycogen content of lean mice, these results also suggest that the metabolic effect is tissue specific, diverting nutrients from adipose tissue to other tissues that have a higher metabolic rate. It circulates in the blood and acts on different tissue including the hypothalamus, skeletal muscle, and liver. Increased obese mRNA expression in omental fat cells from massively obese humans. R and D Systems 4. What is Leptin?

Citrate synthase was used muce a general marker for oxidative capacity and was assayed as described by Srere Early and late stimulation of ob mRNA expression in meal-fed and overfed rats. Gill KAmit ZA Effects of serotonin uptake blockade on food, water and ethanol consumption in rats. Figure 1: The Leptin feedback loop.

Expression of UCP mRNA intrascapular brown fat from lean and obese mice infused for 7 days with increasing amounts of human recombinant leptin. Proc Soc Exp Biol Med ; : — Endocrine and metabolic effects of experimental obesity in man. Search Search articles by subject, keyword or author.

The American journal of clinical nutrition. Proc Univ Micd Med School ; 31 : 29—3. There was no significant effect of leptin or of an interaction between genotype and leptin on any of the parameters; therefore, the means for the two genotypes are the average from all animals in the experiment. Mice in the CR group re-gained their lost body weight within 8 days of ad libitum feeding CR: Exp Animals ; 18 : — Download PDF. In humans and rodents with intact leptin signaling, weight reduction imposed by caloric restriction reduces energy expenditure more than predicted by remaining metabolic mass [ 468921 ].

Brown adipose UCP levels and rectal temperature were also elevated with high doses of leptin, as discussed below, and it is likely that the associated elevation of ovesity expenditure contributed to weight loss in these mice. Expression of the functional leptin receptor mRNA in pancreatic islets and direct inhibitory action of leptin on insulin secretion. The difference in these results and those reported previously 18 may be due to the short duration of this experiment, which involved only 7 days of leptin infusion, compared with the 5-day reproductive cycle of mice.

Advanced Search. Daily body weights of the mice experiment shown in Fig. Select Format Select format. Google Scholar. The lack of site specificity and the failure of leptin to correct this difference suggest that it is also unrelated to the energy balance aspects of leptin deficiency. Recombinant leptin exchanges between parabiosed mice but does not reach equilibrium. Citing articles via Google Scholar.

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Although leptin mutation is rare in humans, mutations in the downstream signaling proteins are often found in severe obese patients. Suresh Leptin obesity mice experiment Biology Reports Gastric bypass surgery in lean adolescent mice prevents diet-induced obesity later in life Michael B. Life Sci 28 : — Liraglutide has been tested for its ability to reduce body weight, as well as to prevent or delay the onset of diabetes in UCD-T2DM rats 0. Recent progress in hormone research.

Physiol Behav ; : 70— Reprints and Permissions. CR and AL groups had significantly different body weights throughout the calorie restriction phase Fig 2A. Defense of differing weight set points in diet induced obese and resistant rats. The long-acting GLP-1 derivative NN ameliorates glycemia and increases beta-cell mass in diabetic mice. The diabetic Zucker fatty rat. Gill KAmit ZA Effects of serotonin uptake blockade on food, water and ethanol consumption in rats.

  • The absence of post-restriction hyperphagia is not due to mice reaching their physical e.

  • Leptin also plays a role in reproductive function. In normal metabolism, high leptin levels indicate sufficient energy stores and low levels indicate a starvation mode.

  • In lean mice, hexokinase and HOAD activities increased with a low dose of leptin and then decreased with the higher dose. Student t-tests 2-tailed were conducted to compare AL and CR groups.

  • It has been proposed that one of the leptin receptor subtypes, with a short intracellular domain, may function as a transport protein and regulate leptin uptake into the brain Article Contents Abstract.

Spleen mg. Nature : — Thank you for visiting nature. Correlations of energy expenditure with body composition in AL and CR mice. Am J Physiol ; : R—R

In addition to food intake, leptin also moderates the burning of fatty acids in skeletal obesith, i. There was no experiment of leptin on expression in tissue from lean mice. Science Both of these responses would be consistent with increased sympathetic activity, its associated activation of brown adipose tissue, and vasoconstriction in the skin We have found that this method of protein administration causes excessive, intermittent elevations of the serum leptin concentration There were no effects of genotype on concentrations in the frontal cortex. To date, the majority of studies investigating leptin-sensitive central control of food intake have focused on neuropeptide Y, which is elevated in the hypothalamus of genetically obese mice and rats and is down-regulated by leptin 38 ,

It promotes a-melanocyte-stimulating hormone a-MSHwhich acts as an appetite suppressant. There was no effect of obesith on the temperatures of lean mice. Forty micrograms of protein were loaded in each lane. A systematic review and meta-analysis of prospective studies on obesity and risk of inflammatory bowel disease. Serum immunoreactive-leptin concentrations in normal-weight and obese humans.

  • Interestingly, it also seemed to change food preference because a preferential reduction in candy intake and a relative increase in chow intake were seen after liraglutide treatment in candy-fed rats Journal of Comparative Physiology B

  • Smith, Erin Rodgers, Jeffrey J. Thus, a greater input than output of energy will result in increased fat storage.

  • Insulin sensitivity was measured by fasting insulin and homeostatic model assessment-insulin resistance.

  • It reduces the effects of neuropeptide Y NPYwhich is a feeding stimulant.

  • Interestingly, a persistent weight gain was observed in the mice thereafter.

FXR is a molecular target for the effects of vertical sleeve expeiment. Jeffrey J. Food was placed on the top of the cages and food intake was recorded daily for all mice throughout the study. Both of these responses would be consistent with increased sympathetic activity, its associated activation of brown adipose tissue, and vasoconstriction in the skin Means and standard deviations of both activity and TEE were determined for each bin.

These results confirm that, in congenitally leptin deficient animals, leptin is not required for compensatory reduction leptin obesity mice experiment energy expenditure accompanying weight loss, but suggest that the hyperphagia of the weight-reduced state is leptin-dependent. Atherosclerosis ; : — Enzyme activity was only measured in tissue from three treatment groups per genotype. The six included files are: 1. This relative hyperphagia decreases over the ensuing 7 days, at which point the intake of the weight-reduced animals equals that of the controls [ 7 ].

R and D Systems 4. Rp mg. Oxford Academic. This explanation is true but incomplete. Permissions Icon Permissions. The liver, hypothalamus, brown fat, and gonadal fat were snap-frozen.

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