Ghrelin receptor signalling is not required for glucocorticoid-induced obesity in female mice.

2021 ◽  
Author(s):  
Zachary Silver ◽  
Sam Abbott-Tate ◽  
Lindsay Hyland ◽  
Frances Sherratt ◽  
Barbara Woodside ◽  
...  

Chronic exposure to high circulating glucocorticoid or ghrelin concentrations increases food intake, weight gain and adiposity, suggesting that ghrelin could contribute to the metabolic effects of chronic glucocorticoids. In male mice, however, blocking ghrelin receptor (GHSR) signalling increased the weight gain and adiposity induced by chronic corticosterone (CORT), rather than attenuating them. In the current study, we investigated the role of GHSR signalling in the metabolic effects of chronic exposure to high circulating CORT in female mice. To do this, female WT and GHSR KO mice were treated with either CORT in a 1% ethanol (EtOH) solution or 1% EtOH alone in their drinking water for 32 days (N=5-8/group). Body weight, food, and water intake as well as vaginal cyclicity were assessed daily. As expected, CORT treatment induced significant increases in body weight, food intake, adiposity and also impaired glucose tolerance. In contrast to results observed in male mice, WT and GHSR KO female mice did not differ on any of these parameters. Neither plasma levels of ghrelin, LEAP-2, the endogenous GHSR antagonist produced by the liver, nor their ratio were altered by chronic glucocorticoid exposure. In addition, CORT treatment disrupted vaginal cyclicity, produced a reduction in sucrose consumption and increased locomotor activity regardless of genotype. Chronic CORT also decreased exploration in WT but not GHSR KO mice. Collectively, these data suggest that most metabolic, endocrine, reproductive and behavioral effects of chronic CORT exposure are independent of GHSR signalling in female mice.

2020 ◽  
Author(s):  
Clayton Spada ◽  
Chau Vu ◽  
Iona Raymond ◽  
Warren Tong ◽  
Chia-Lin Chuang ◽  
...  

Abstract Background Bimatoprost negatively regulates adipogenesis in vitro and likely participates in a negative feedback loop on anandamide-induced adipogenesis. Here, we investigate the broader metabolic effects of bimatoprost action in vivo in rats under both normal state and obesity-inducing conditions. Methods Male Sprague Dawley rats were a fed standard chow (SC) diet in conjunction with dermally applied bimatoprost treatment for a period of 9–10 weeks. Body weight gain, energy expenditure, food intake, and hormones associated with satiety were measured. Gastric emptying was also separately evaluated. In obesity-promoting diet studies, rats were fed a cafeteria diet (CAF) and gross weight, fat accumulation in SQ, visceral fat and liver was evaluated together with standard serum chemistry. Results Chronic bimatoprost administration attenuated weight gain in rats fed either standard or obesity-promoting diets over a 9–10 weeks. Bimatoprost increased satiety as measured by decreased food intake, gastric emptying and circulating gut hormone levels. Additionally, SQ and visceral fat mass was distinctly affected by treatment. Bimatoprost increased satiety as measured by decreased food intake, gastric emptying and circulating gut hormone levels. Conclusions These findings suggest that bimatoprost (and possibly prostamide F2α) regulates energy homeostasis through actions on dietary intake. These actions likely counteract the metabolic actions of anandamide through the endocannabinoid system potentially revealing a new pathway that could be exploited for therapeutic development.


2020 ◽  
Vol 319 (1) ◽  
pp. E146-E162 ◽  
Author(s):  
Stefanie Y. Tan ◽  
Xia Lei ◽  
Hannah C. Little ◽  
Susana Rodriguez ◽  
Dylan C. Sarver ◽  
...  

Secreted hormones facilitate tissue cross talk to maintain energy balance. We previously described C1q/TNF-related protein 12 (CTRP12) as a novel metabolic hormone. Gain-of-function and partial-deficiency mouse models have highlighted important roles for this fat-derived adipokine in modulating systemic metabolism. Whether CTRP12 is essential and required for metabolic homeostasis is unknown. We show here that homozygous deletion of Ctrp12 gene results in sexually dimorphic phenotypes. Under basal conditions, complete loss of CTRP12 had little impact on male mice, whereas it decreased body weight (driven by reduced lean mass and liver weight) and improved insulin sensitivity in female mice. When challenged with a high-fat diet, Ctrp12 knockout (KO) male mice had decreased energy expenditure, increased weight gain and adiposity, elevated serum TNFα level, and reduced insulin sensitivity. In contrast, female KO mice had reduced weight gain and liver weight. The expression of lipid synthesis and catabolism genes, as well as profibrotic, endoplasmic reticulum stress, and oxidative stress genes were largely unaffected in the adipose tissue of Ctrp12 KO male mice. Despite greater adiposity and insulin resistance, Ctrp12 KO male mice fed an obesogenic diet had lower circulating triglyceride and free fatty acid levels. In contrast, lipid profiles of the leaner female KO mice were not different from those of WT controls. These data suggest that CTRP12 contributes to whole body energy metabolism in genotype-, diet-, and sex-dependent manners, underscoring complex gene-environment interactions influencing metabolic outcomes.


Endocrinology ◽  
2020 ◽  
Vol 162 (1) ◽  
Author(s):  
Hailan Liu ◽  
Chunmei Wang ◽  
Meng Yu ◽  
Yongjie Yang ◽  
Yang He ◽  
...  

Abstract AbstractCentral 5-hydroxytryptamine (5-HT), which is primarily synthesized by tryptophan hydroxylase 2 (TPH2) in the dorsal Raphe nuclei (DRN), plays a pivotal role in the regulation of food intake and body weight. However, the physiological functions of TPH2 on energy balance have not been consistently demonstrated. Here we systematically investigated the effects of TPH2 on energy homeostasis in adult male and female mice. We found that the DRN harbors a similar amount of TPH2+ cells in control male and female mice. Adult-onset TPH2 deletion in the DRN promotes hyperphagia and body weight gain only in male mice, but not in female mice. Ablation of TPH2 reduces hypothalamic pro-opiomelanocortin (POMC) neuronal activity robustly in males, but only to a modest degree in females. Deprivation of estrogen by ovariectomy (OVX) causes comparable food intake and weight gain in female control and DRN-specific TPH2 knockout mice. Nevertheless, disruption of TPH2 blunts the anorexigenic effects of exogenous estradiol (E2) and abolishes E2-induced activation of POMC neurons in OVX female mice, indicating that TPH2 is indispensable for E2 to activate POMC neurons and to suppress appetite. Together, our study revealed that TPH2 in the DRN contributes to energy balance regulation in a sexually dimorphic manner.


1973 ◽  
Vol 51 (12) ◽  
pp. 1604-1616 ◽  
Author(s):  
B. Szepesi

Starvation followed by refeeding a 65% glucose diet led to elevated levels of hepatic glucose-6-phosphate dehydrogenase and malic enzyme activity. A second starve–refeed episode led to even greater enzyme responses. Food intake and body weight gain were increased by one, and further increased by a second, starve–refeed episode. Prefeeding a 65% fructose or sucrose diet ad libitum (which results in elevated enzyme levels comparable with the effect of one starve–refeed episode) was not accompanied by increased food intake or body-weight gain, nor did such treatment increase the enzyme response to subsequent starvation–refeeding. Previous starvation, however, did increase the subsequent enzyme response to feeding ad libitum a diet containing sucrose or invert sugar. The enzyme response was greater when the sucrose-containing diet was fed, and the diet effect was independent of the treatment effect. The results suggest that: (1) the metabolic consequences of starvation–refeeding are longer lasting than the metabolic consequences of feeding fructose or sucrose, (2) the effect of dietary sucrose is greater than the effect of an equal amount of invert sugar, (3) the metabolic effects of dietary fructose and sucrose may be mediated by different mechanisms than the corresponding effects of starvation–refeeding.


2018 ◽  
Vol 32 (5) ◽  
pp. 533-540 ◽  
Author(s):  
Jacob S Ballon ◽  
Utpal B Pajvani ◽  
Laurel ES Mayer ◽  
Zachary Freyberg ◽  
Robin Freyberg ◽  
...  

Second generation antipsychotics are prescribed for an increasing number of psychiatric conditions, despite variable associations with weight gain, dyslipidemia, and impaired glucose tolerance. The mechanism(s) of the apparent causal relationships between these medications and metabolic effects have been inadequately defined and are potentially confounded by genetic risk of mental illness, attendant lifestyle, and concomitant medications. Therefore, we conducted a study in which 24 healthy volunteers were randomized to olanzapine (highly weight-gain liability), iloperidone (less weight-gain liability), or placebo treatment for 28 days under double-blind conditions. We hypothesized that antipsychotics induce weight gain primarily through increased caloric intake, which causes secondary dyslipidemia and insulin resistance. Subjects were phenotyped pre- and post-treatment for body weight, adiposity by dual energy X-ray absorptiometry, energy expenditure by indirect calorimetry, food intake, oral glucose tolerance, plasma lipids, glucose, insulin, and other hormones. We found significantly increased food intake and body weight but no change in energy expenditure in olanzapine-treated subjects, with associated trends towards lipid abnormalities and insulin resistance the extent of which were presumably limited by the duration of treatment. Iloperidone treatment led to modest non-significant and placebo no weightgain, lipid increases and alterations in insulin metabolism. We conclude that second generation antipsychotic drugs, as represented by olanzapine, produce their weight and metabolic effects, predominantly, by increasing food intake which leads to weight gain that in turn induces metabolic consequences, but also through other direct effects on lipid and glucose metabolism independant of food intake and weight gain.


1986 ◽  
Vol 250 (5) ◽  
pp. E518-E522 ◽  
Author(s):  
R. Racotta ◽  
L. Ramirez-Altamirano ◽  
E. Velasco-Delgado

Chronic infusions of epinephrine, norepinephrine, or vehicle were performed in adult male rats by means of subcutaneous implanted osmotic minipumps (ALZET). The calculated dose was 180 ng/min during 7-8 days. Daily food intake and body weight were measured during this period and also 7 days before and 5 days after it. During the period of infusion, norepinephrine stopped body weight gain while epinephrine-infused rats gained weight at the same rate as controls. Once the infusion period was finished, epinephrine-infused rats gained more weight than controls, while norepinephrine-infused rats just returned to the slope of weight gain of the controls. In no group did food intake change. In a second experiment, similar infusions were carried out in other rats on the same schedule; body temperature, glycemia, and serum insulin and triiodothyronine were measured. Epinephrine infusion significantly elevated glycemia and triiodothyronine, whereas norepinephrine infusion increased temperature and serum insulin. The results obtained by chronic administration of the catecholamines support the concept of a disassociation of adrenomedullary and sympathetic nervous system metabolic effects.


2020 ◽  
Vol 9 (4) ◽  
pp. 353-370 ◽  
Author(s):  
Jian Zhang ◽  
Catherine A Powell ◽  
Matthew K Kay ◽  
Min Hi Park ◽  
Sunitha Meruvu ◽  
...  

Abstract Exposure to endocrine disrupting chemicals (EDCs) used in plastic manufacturing processes may be contributing to the current increase in metabolic disorders. Here, we determined that benzyl butyl phthalate (BBP), a common EDC and food packaging plasticizer, mixed into chow diet (CD) and high fat diets (HFD) at varying concentrations (4 μg/kg body weight (bw)/day, 169 μg/kg bw/day, 3 mg/kg bw/day, 50 mg/kg bw/day) produced a number of detrimental and sex-specific metabolic effects in C57BL/6 male and female mice after 16 weeks. Male mice exposed to moderate (3 mg/kg bw/day) concentrations of BBP in an HFD were especially affected, with significant increases in body weight due to significant increases in weight of liver and adipose tissue. Other doses did not show any significant changes when compared to only CD or HFD alone. HFD in the presence of 3 mg/kg bw/day BBP showed significant increases in fasting blood glucose, glucose intolerance, and insulin intolerance when compared to HFD alone. Furthermore, this group significantly alters transcriptional regulators involved in hepatic lipid synthesis and its downstream pathway. Interestingly, most of the BBP doses had no phenotypic effect when mixed with CD and compared to CD alone. The female mice did not show a similar response as the male population even though they consumed a similar amount of food. Overall, these data establish a dose which can be used for a BBP-induced metabolic research model and suggest that a moderate dosage level of EDC exposure can contribute to widely ranging metabolic effects.


2019 ◽  
Vol 8 (1) ◽  
pp. 35 ◽  
Author(s):  
Nicolas Lucas ◽  
Romain Legrand ◽  
Camille Deroissart ◽  
Manon Dominique ◽  
Saïda Azhar ◽  
...  

Use of new generation probiotics may become an integral part of the prevention and treatment strategies of obesity. The aim of the present study was to test the efficacy of a potential probiotic strain of lactic bacteria Hafnia alvei (H. alvei) HA4597™, in a mouse model of obesity characterized by both hyperphagia and diet-induced adiposity. For this purpose, 10-week-old high-fat-diet (HFD)-fed hyperphagic ob/ob male mice received a daily treatment with 1.4 × 1010 CFU of H. alvei for 38 days. Effects of H. alvei were compared to those of a lipase inhibitor orlistat (80 mg/kg daily) and a vehicle (NaCl 0.9%) in HFD-fed ob/ob mice. A control untreated group of ob/ob mice received the standard diet throughout the experiment. The vehicle-treated HFD group displayed increased food intake, worsening of adiposity, and glycemia. Treatment with H. alvei was accompanied by decreased body weight and fat-mass gain along with reduced food intake to the level of the standard-diet-fed mice. At the end of the experiment, the group treated with H. alvei showed a decrease of glycemia, plasma total cholesterol, and alanine aminotransferase. The orlistat-treated mice showed a lower rate of body weight gain but were hyperphagic and hyperglycemic. These results demonstrate the beneficial anti-obesity and metabolic effects of H. alvei HA4597™ in mice with obesity resulting from hyperphagia and diet-induced adiposity.


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