Social defeat and footshock increase body mass and adiposity in male Syrian hamsters

2007 ◽  
Vol 292 (1) ◽  
pp. R283-R290 ◽  
Author(s):  
Matia B. Solomon ◽  
Michelle T. Foster ◽  
Timothy J. Bartness ◽  
Kim L. Huhman
Keyword(s):  
Food Intake ◽  
Body Mass ◽  
Social Stress ◽  
Social Defeat ◽  
Mass Gain ◽  
Syrian Hamsters ◽  
Laboratory Rats ◽  
Footshock Stress ◽  
Lipid Mass ◽  
Increase Food Intake

Obesity is a world-wide epidemic, and many factors, including stress, have been linked to this growing trend. After social stress (i.e., defeat), subordinate laboratory rats and most laboratory mice become hypophagic and, subsequently, lose body mass; the opposite is true of subordinate Syrian hamsters. After social defeat, Syrian hamsters become hyperphagic and gain body mass compared with nonstressed controls. It is unknown whether this increase in body mass and food intake is limited to subordinate hamsters. In experiment 1, we asked, do dominant hamsters increase food intake, body mass, and adiposity after an agonistic encounter? Subordinate hamsters increased food intake and body mass compared with nonstressed controls. Although there was no difference in food intake or absolute body mass between dominant and nonstressed control animals, cumulative body mass gain was significantly higher in dominant than in nonstressed control animals. Total carcass lipid and white adipose tissue (WAT) (i.e., retroperitoneal and epididymal WAT) masses were significantly increased in subordinate, but not dominant, hamsters compared with nonstressed controls. In experiment 2, we asked, does footshock stress increase food intake, body mass, and adiposity. Hamsters exposed to defeat, but not footshock stress, increased food intake relative to nonstressed controls. In animals exposed to defeat or footshock stress, body mass, as well as mesenteric WAT mass, increased compared with nonstressed controls. Collectively, these data demonstrate that social and nonsocial stressors increase body and lipid mass in male hamsters, suggesting that this species may prove useful for studying the physiology of stress-induced obesity in some humans.

Social defeat increases food intake, body mass, and adiposity in Syrian hamsters

2006 ◽  
Vol 290 (5) ◽  
pp. R1284-R1293 ◽  
Author(s):  
Michelle T. Foster ◽  
Matia B. Solomon ◽  
Kim L. Huhman ◽  
Timothy J. Bartness
Keyword(s):  
Food Intake ◽  
Body Mass ◽  
Interaction Model ◽  
Social Defeat ◽  
Syrian Hamsters ◽  
Laboratory Rats ◽  
Increase Food Intake ◽  
Human Stress ◽  
Natural Stressor ◽  
Resident Intruder

Overeating and increases in body and fat mass are the most common responses to day-to-day stress in humans, whereas stressed laboratory rats and mice respond oppositely. Group housing of Syrian hamsters increases body mass, adiposity, and food intake, perhaps due to social confrontation-induced stress. In experiment 1 we asked, Does repeated social defeat increase food intake, body mass, and white adipose tissue (WAT) mass in Syrian hamsters? Male hamsters subjected to the resident-intruder social interaction model and defeated intermittently 15 times over 34 days for 7-min sessions significantly increased their food intake, body mass, and most WAT masses compared with nondefeated controls. Defeat significantly increased terminal adrenal norepinephrine, but not epinephrine, content. In experiment 2 we asked, Are 15 intermittent resident-intruder interactions necessary to increase body mass and food intake? Body mass and food intake of subordinate hamsters defeated only once were similar to those of nondefeated controls, but four or eight defeats similarly and significantly increased these responses. In experiment 3 we asked, Do intermittent defeats increase adiposity and food intake more than consecutive defeats? Four intermittent or consecutive defeats similarly and significantly increased food intake and body mass compared with nondefeated controls, but only intermittent defeats significantly increased all WAT masses. Consecutive defeats significantly increased mesenteric and inguinal WAT masses. Plasma leptin, but not insulin, concentrations were similarly and significantly increased compared with nondefeated controls. Collectively, social defeat, a natural stressor, significantly increased food intake, body mass, and adiposity in Syrian hamsters and may prove useful in determining mechanisms underlying human stress-induced obesity.

scholarly journals Differential effects of glucocorticoids on energy homeostasis in Syrian hamsters

2011 ◽  
Vol 301 (2) ◽  
pp. E307-E316 ◽  
Author(s):  
Matia B. Solomon ◽  
Randall R. Sakai ◽  
Stephen C. Woods ◽  
Michelle T. Foster
Keyword(s):  
Food Intake ◽  
Body Mass ◽  
Energy Homeostasis ◽  
Fat Tissue ◽  
Thymic Involution ◽  
Syrian Hamsters ◽  
Differential Effects ◽  
Body Adiposity ◽  
Increase Food Intake ◽  
Response To Stress

Syrian hamsters, like many humans, increase food intake and body adiposity in response to stress. We hypothesized that glucocorticoids (cortisol and corticosterone) mediate these stress-induced effects on energy homeostasis. Because Syrian hamsters are dual secretors of cortisol and corticosterone, differential effects of each glucocorticoid on energy homeostasis were investigated. First, adrenal intact hamsters were injected with varying physiological concentrations of cortisol, corticosterone, or vehicle to emulate our previously published defeat regimens (i.e., 1 injection/day for 5 days). Neither food intake nor body weight was altered following glucocorticoid injections. Therefore, we investigated the effect of sustained glucocorticoid exposure on energy homeostasis. This was accomplished by implanting hamsters with supraphysiological steady-state pellets of cortisol, corticosterone, or cholesterol as a control. Cortisol, but not corticosterone, significantly decreased food intake, body mass, and lean and fat tissue compared with controls. Despite decreases in body mass and adiposity, cortisol significantly increased circulating free fatty acids, triglyceride, cholesterol, and hepatic triglyceride concentrations. Although corticosterone did not induce alterations in any of the aforementioned metabolic end points, Syrian hamsters were responsive to the effects of corticosterone since glucocorticoids both induced thymic involution and decreased adrenal mass. These findings indicate that cortisol is the more potent glucocorticoid in energy homeostasis in Syrian hamsters. However, the data suggest that cortisol alone does not mediate stress-induced increases in food intake or body mass in this species.

Food hoarding is increased by food deprivation and decreased by leptin treatment in Syrian hamsters

2003 ◽  
Vol 285 (5) ◽  
pp. R1021-R1029 ◽  
Author(s):  
Carolyn A. Buckley ◽  
Jill E. Schneider
Keyword(s):  
Food Intake ◽  
Food Deprivation ◽  
Syrian Hamsters ◽  
Laboratory Rats ◽  
Hoarding Behavior ◽  
Increase Food Intake ◽  
Ad Libitum ◽  
Access To Food ◽  
Plasma Leptin ◽  
Rats And Mice

Compensatory increases in food intake are commonly observed after a period of food deprivation in many species, including laboratory rats and mice. Thus it is interesting that Syrian hamsters fail to increase food intake after a period of food deprivation, despite a fall in plasma leptin concentrations similar to those seen in food-deprived rats and mice. In previous laboratory studies, food-deprived Syrian hamsters increased the amount of food hoarded. We hypothesized that leptin treatment during food deprivation would attenuate food-deprivation-induced increases in hoarding. Baseline levels of hoarding were bimodally distributed, with no hamsters showing intermediate levels of hoarding. Both high (HH) and low hoarding (LH) hamsters were included in each experimental group. Fifty-six male hamsters were either food deprived or given ad libitum access to food for 48 h. One-half of each group received intraperitoneal injections of leptin (4 mg/kg) or vehicle every 12 h during the food-deprivation period. Within the HH group, the hoarding score increased significantly in food-deprived but not fed hamsters ( P < 0.05). Leptin treatment significantly decreased hoarding in the food-deprived HH hamsters ( P < 0.05). The LH hamsters did not increase hoarding regardless of whether they were food deprived or had ad libitum access to food. These results are consistent with the idea that HH hamsters respond to energetic challenges at least in part by changing their hoarding behavior and that leptin might be one factor that mediates this response.

Effects of neurosecretory protein GL on food intake and fat accumulation under different dietary nutrient compositions in rats

2021 ◽  
Author(s):  
Keisuke Fukumura ◽  
Kenshiro Shikano ◽  
Yuaki Narimatsu ◽  
Eiko Iwakoshi-Ukena ◽  
Megumi Furumitsu ◽  
...  
Keyword(s):  
Food Intake ◽  
Feeding Behavior ◽  
Body Mass ◽  
Mass Gain ◽  
Chow Diet ◽  
Tissue Mass ◽  
Fat Accumulation ◽  
Intracerebroventricular Infusion ◽  
Body Mass Gain ◽  
Sucrose Diet

Abstract We recently identified a novel hypothalamic small protein, named neurosecretory protein GL (NPGL), which is involved in energy homeostasis in birds and mammals. However, whether the action of NPGL is influenced by nutritional composition remains unknown. Thus, we investigated the effect of chronic intracerebroventricular infusion of NPGL for 13 days on feeding behavior and body mass gain under a normal chow diet (NC), high-fat diet, high-sucrose diet (HSD), and medium-fat/medium-sucrose diet (MFSD) in rats. NPGL stimulated food intake of NC and MFSD, especially during the light period. By contrast, NPGL decreased body mass gain under NC and increased total white adipose tissue mass in HSD- and MFSD-fed rats. These data suggest that the effects of NPGL on feeding behavior, body mass gain, and fat accumulation depend on nutrient type. Among them, sucrose in diets seems to contribute to fat accumulation elicited by NPGL.

Effects of the fructose analog, 2,5-anhydro-D-mannitol, on food intake and estrous cyclicity in Syrian hamsters

1997 ◽  
Vol 272 (3) ◽  
pp. R935-R939
Author(s):  
J. E. Schneider
Keyword(s):  
Food Intake ◽  
Plasma Glucose ◽  
Acid Oxidation ◽  
Estrous Cycles ◽  
Syrian Hamsters ◽  
Glucose Levels ◽  
Fuel Metabolism ◽  
Increase Food Intake ◽  
Estrous Cyclicity ◽  
Estrous Cycling

Hyperphagia and anovulation are both triggered by prior food deprivation or other treatments that decrease intracellular availability of metabolic fuels in most species studied. Syrian hamsters fail to show compensatory hyperphagia, but do show anestrus in response to these energetic challenges. In the present experiments, we examined food intake, plasma glucose levels, and estrous cyclicity in Syrian hamsters in response to 2,5-anhydro-D-mannitol (2,5-AM), a fructose analog that is thought to trigger eating in rats by depleting intracellular levels of ATP. In experiment 1, female estrous cycling hamsters were treated with 100, 200, 400, or 800 mg/kg 2,5-AM or the vehicle by intraperitoneal injection. Food intake was measured 1, 2, 4, 8, and 24 h after treatment. There were no statistically significant increases in food intake in response to any dose of 2,5-AM. In experiment 2, blood samples were drawn at 0, 1, 3, 5, 7, and 25 h after hamsters were treated with 0 or 400 mg/kg 2,5-AM. 2,5-AM treatment resulted in a mild but significant decrease in plasma glucose levels similar to those seen in 2,5-AM-treated rats, suggesting that 2,5-AM has similar effects on fuel metabolism in rats and hamsters. In experiment 3, hamsters received 2,5-AM, 2,5-AM plus the fatty acid oxidation inhibitor methyl palmoxirate, or vehicle every 6 h over the first 48 h of the estrous cycle and were tested for indexes of estrous cyclicity at the end of the cycle. All hamsters showed normal estrous cycles, regardless of treatment. If 2,5-AM has similar metabolic consequences in rats and hamsters, the present results suggest that decreased intracellular levels of ATP and mild hypoglycemia do not increase food intake or inhibit estrous cyclicity in Syrian hamsters.

scholarly journals Foraging dive frequency predicts body mass gain in the Adélie penguin

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amélie Lescroël ◽  
Annie Schmidt ◽  
Megan Elrod ◽  
David G. Ainley ◽  
Grant Ballard
Keyword(s):  
Food Intake ◽  
Foraging Behavior ◽  
Body Mass ◽  
Marine Environment ◽  
Mass Gain ◽  
Rfid Tags ◽  
Wild Animals ◽  
Foraging Success ◽  
Body Mass Gain ◽  
Adélie Penguins

AbstractQuantifying food intake in wild animals is crucial to many ecological and evolutionary questions, yet it can be very challenging, especially in the marine environment. Because foraging behavior can be inferred from dive recordings in many marine creatures, we hypothesized that specific behavioral dive variables can indicate food intake. To test this hypothesis, we attached time-depth recorders to breeding Adélie penguins also implanted with RFID tags that crossed a weighbridge as they traveled to and from the ocean to feed their chicks. The weighbridge reported how much mass the penguin had gained during a foraging trip. The variables that explained a significant amount of the change in body mass while at sea were the number of foraging dives per hour (46%) and the number of undulations per hour (12%). Most importantly, every increment of 1 in the rate of foraging dives per hour equated to a penguin gaining an average 170 g of mass, over the course of a 6–60 h foraging trip. These results add to a growing understanding that different metrics of foraging success are likely appropriate for different species, and that assessing the types and frequencies of dives using time-depth recorders can yield valuable insights.

scholarly journals Short-term menthol treatment promotes persistent thermogenesis without induction of compensatory food consumption in Wistar rats: implications for obesity control

2018 ◽  
Vol 124 (3) ◽  
pp. 672-683 ◽  
Author(s):  
Robson Cristiano Lillo Vizin ◽  
Anna Carolina P. Motzko-Soares ◽  
Giovana Marchini Armentano ◽  
Débora T. Ishikawa ◽  
Ariovaldo P. Cruz-Neto ◽  
...  
Keyword(s):  
Food Intake ◽  
Energy Expenditure ◽  
Body Mass ◽  
Wistar Rats ◽  
Transient Receptor Potential ◽  
Mass Gain ◽  
Term Treatment ◽  
Short Term ◽  
Short Term Treatment ◽  
Cutaneous Vasoconstriction

In this study, we aimed to evaluate the influence of daily repeated menthol treatments on body mass and thermoregulatory effectors in Wistar rats, considering that menthol is a transient receptor potential melastatin 8 channel agonist that mimics cold sensation and activates thermoregulatory cold-defense mechanisms in mammals, promoting hyperthermia and increasing energy expenditure, and has been suggested as an anti-obesity drug. Male Wistar rats were topically treated with 5% menthol for 3 or 9 consecutive days while body mass, food intake, abdominal temperature, metabolism, cutaneous vasoconstriction, and thermal preference were measured. Menthol promoted hyperthermia on all days of treatment, due to an increase in metabolism and cutaneous vasoconstriction, without affecting food intake, resulting in less mass gain in menthol-hyperthermic animals. As the treatment progressed, the menthol-induced increases in metabolism and hyperthermia were attenuated but not abolished. Moreover, cutaneous vasoconstriction was potentiated, and an increase in the warmth-seeking behavior was induced. Taken together, the results suggest that, although changes occur in thermoeffector recruitment during the course of short-term treatment, menthol is a promising drug to prevent body mass gain. NEW & NOTEWORTHY Menthol produces a persistent increase in energy expenditure, with limited compensatory thermoregulatory adaptations and, most unexpectedly, without affecting food intake. Thus short-term treatment with menthol results in less mass gain in treated animals compared with controls. Our results suggest that menthol is a promising drug for the prevention of obesity.

Hyperhomocysteinemia induced by methionine nutritional overload more promptly affects brain than heart cholinergic system without affects on food intake and body mass gain

2017 ◽  
Vol 263 ◽  
pp. e168
Author(s):  
Dragan Hrncic ◽  
Aleksandra Rasic-Markovic ◽  
Mirjana Colovic ◽  
Danijela Krstic ◽  
Nikola Sutulovic ◽  
...  
Keyword(s):  
Food Intake ◽  
Body Mass ◽  
Cholinergic System ◽  
Mass Gain ◽  
Body Mass Gain

Agouti-related protein increases food hoarding more than food intake in Siberian hamsters

2004 ◽  
Vol 286 (1) ◽  
pp. R38-R45 ◽  
Author(s):  
Diane E. Day ◽  
Timothy J. Bartness
Keyword(s):  
Food Intake ◽  
Arcuate Nucleus ◽  
Third Ventricle ◽  
Mass Gain ◽  
Dark Phase ◽  
Related Protein ◽  
Food Hoarding ◽  
Laboratory Rats ◽  
Siberian Hamsters ◽  
Agouti Related Protein

Agouti-related protein (AgRP), an endogenous melanocortin 3/4 receptor antagonist, appears to play an important role in the control of food intake and energy balance because exogenous administration in rats and overexpression in mice result in hyperphagia and body mass gain. Furthermore, arcuate nucleus AgRP mRNA is increased with fasting in laboratory rats and mice and is decreased with refeeding. In Siberian hamsters, fasting also increases arcuate nucleus AgRP mRNA, but these animals increase food hoarding, rather than food intake with refeeding. Therefore, we tested whether exogenous AgRP increased food hoarding in this species. Hamsters were trained in a hoarding/foraging apparatus to run a programmed number of wheel revolutions to earn food pellets. Four doses of AgRP-(83-132) or vehicle were injected into the third ventricle at the beginning of the dark phase, and food hoarding, food intake, and foraging were measured at various time points subsequently. Overall, food hoarding was stimulated as much as 10 times more than food intake, and both responses occurred as early as 1 h after injection. Food hoarding was increased the greatest at the lowest dose (0.1 nmol), whereas food intake was increased the greatest at the second lowest dose (1 nmol). Food intake and especially food hoarding were increased up to seven days after the AgRP injections. Foraging was increased at all AgRP doses except the highest dose (100 nmol). These results suggest that AgRP triggers the search for food in this species, and once they find it, hoarding predominates over eating.

scholarly journals A Single Dose of Ginkgo biloba Extract Induces Gene Expression of Hypothalamic Anorexigenic Effectors in Male Rats

2021 ◽  
Vol 11 (12) ◽  
pp. 1602
Author(s):  
Meira M. F. Machado ◽  
Janilda P. Pereira ◽  
Bruna K. S. Hirata ◽  
Viviane S. Júlio ◽  
Renata M. Banin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Food Intake ◽  
Body Mass ◽  
Ginkgo Biloba ◽  
Mass Gain ◽  
Ginkgo Biloba Extract ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Protein Levels ◽  
Rapid Stimulation

Previous studies have shown that Ginkgo biloba extract (GbE) reduces food intake and body mass gain and regulates proteins related to lipid metabolism in obese rats. In ovariectomized rats, GbE restored the hippocampal and hypothalamic serotonergic system activity, favoring the spontaneous feeding decrement. Considering the promising hypophagic effect of GbE, this study aimed to investigate the effect of a single acute dose on hypothalamic pathways that regulate feeding behavior in male rats. Four-month-old Wistar male rats received either a single acute oral GbE dose (500 mg/kg) or vehicle. Food intake and body mass were measured after 1, 4, 12, and 24 h. Rats were euthanized, and hypothalami were removed for mRNA quantification of anorexigenic (POMC/CART) and orexigenic (AgRP/NPY) neuropeptides, leptin/serotonin receptors (5HT1A, 5HT1B, 5HT2C), and serotonin transporters. We also investigated POMC, 5-HT1B, and 5-HT2C protein levels. A single acute GbE dose induced the hypothalamic POMC, CART, and 5-HT2C gene expression but failed to modify orexigenic effectors. No alterations in food intake, body mass, and hypothalamic protein levels were observed. In summary, the present findings demonstrate the rapid stimulation of pivotal hypothalamic anorexigenic pathways in response to a single GbE administration, reinforcing the GbE hypophagic activity. However, more studies are necessary to evaluate its potential as an appetite modulator.

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