scholarly journals Orexigenic response to tail pinch: role of brain NPY1 and corticotropin releasing factor receptors

2014 ◽  
Vol 306 (3) ◽  
pp. R164-R174 ◽  
Author(s):  
Miriam Goebel-Stengel ◽  
Andreas Stengel ◽  
Lixin Wang ◽  
Yvette Taché

Tail pinch stimulates food intake in rats. We investigated brain mechanisms of this response and the influence of repeated exposure. Sprague-Dawley rats received acute (5 min) or repeated (5 min/day for 14 days) tail pinch using a padded clip. Acute tail pinch increased 5-min food intake compared with control (0.92 ± 0.2 vs. 0.03 ± 0.01 g, P < 0.01). This response was inhibited by 76% by intracerebroventricular injection of BIBP-3226, a neuropeptide Y1 (NPY1) receptor antagonist, increased by 48% by astressin-B, a corticotropin-releasing factor (CRF) receptor antagonist, and not modified by S-406-028, a somatostatin subtype 2 antagonist. After the 5-min tail pinch without food, blood glucose rose by 21% ( P < 0.01) while changes in plasma acyl ghrelin (+41%) and adrenocorticotropic hormone (+37%) were not significant. Two tail pinches (45 min apart) activate pontine and hindbrain catecholaminergic and hypothalamic paraventricular CRF neurons. After 14 days of repeated tail pinch, the 5-min orexigenic response was not significantly different from days 2 to 11 but reduced by 50% thereafter ( P < 0.001). Simultaneously, the 5-min fecal pellet output increased during the last 5 days compared with the first 5 days (+58%, P < 0.05). At day 14, the body weight gain was reduced by 22%, with a 99% inhibition of fat gain and a 25% reduction in lean mass ( P < 0.05). The orexigenic response to acute 5-min tail pinch is likely to involve the activation of brain NPY1 signaling, whereas that of CRF tends to dampen the acute response and may contribute to increased defecation and decreased body weight gain induced by repeated tail pinch.

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.


2003 ◽  
Vol 285 (4) ◽  
pp. R791-R799 ◽  
Author(s):  
Chantal Michel ◽  
Barry E. Levin ◽  
Ambrose A. Dunn-Meynell

To assess the interaction between stress and energy homeostasis, we immobilized male Sprague-Dawley rats prone to diet-induced obesity (DIO) or diet resistance (DR) once for 20 min and then fed them either low-fat (4.5%) chow or a medium-fat (31%), high-energy (HE) diet for 9 days. Stressed, chow-fed DIO rats gained less, while stressed DIO rats on HE diet gained more body weight and had higher feed efficiency and plasma leptin levels than unstressed controls. Neither stress nor diet affected DR body weight gain. While stress-induced plasma corticosterone levels did not differ between phenotypes, DIO rats were initially more active in an open field and had higher hippocampal dentate gyrus and CA1 glucocorticoid receptor (GR) mRNA than DR rats, regardless of prior stress or diet. HE diet intake was associated with raised dentate gyrus and CA1 GR and amygdalar central nucleus (CeA) corticotropin-releasing hormone (CRH) mRNA expression, while stress was associated with reduced hypothalamic dorsomedial nucleus Ob-R mRNA and CeA CRH specifically in DIO rats fed HE diet. Thus a single stress triggers a complex interaction among weight gain phenotype, diet, and stress responsivity, which determines the body weight and adiposity of a given individual.


2003 ◽  
Vol 284 (6) ◽  
pp. R1560-R1566 ◽  
Author(s):  
Amit Varma ◽  
Jing He ◽  
Lisa Weissfeld ◽  
Sherin U. Devaskar

We investigated the effect of repetitive postnatal (2–7 days) intracerebroventricular administration of neuropeptide Y (NPY) on food intake and body weight gain in the 3- to 120-day-old Sprague-Dawley rats. NPY caused a 32% transient increase in body weight gain with elevated circulating insulin concentrations within 24 h. This early intervention led to the persistence of hyperinsulinemia and relative hyperleptinemia with euglycemia in the 120-day-old female alone. This perturbation was associated with 50% suppression in adult female hypothalamic NPY concentrations and a 50–85% decline in NPY immunoreactivity in the paraventricular and arcuate nuclei. This change was paralleled by a ∼20% decline in food intake and body weight gain at 60 and 120 days. However, when exogenous NPY was stereotaxically reinjected into the paraventricular nucleus of the ∼120-day-old adult females who were pretreated with NPY postnatally, an increase in food intake and body weight gain was noted, attesting to no disruption in the NPY end-organ responsivity. We conclude that postnatal intracerebroventricular NPY has long-lasting effects that predetermine the resultant adult phenotype in a sex-specific manner.


Peptides ◽  
2001 ◽  
Vol 22 (3) ◽  
pp. 483-491 ◽  
Author(s):  
A.J Danielsa ◽  
W.T Chance ◽  
M.K Grizzle ◽  
D Heyer ◽  
J.E Matthews

2019 ◽  
Vol 317 (2) ◽  
pp. E337-E349
Author(s):  
Elizabeth T. Nguyen ◽  
Sarah Berman ◽  
Joshua Streicher ◽  
Christina M. Estrada ◽  
Jody L. Caldwell ◽  
...  

Psychological stress and excess glucocorticoids are associated with metabolic and cardiovascular diseases. Glucocorticoids act primarily through mineralocorticoid (MR) and glucocorticoid receptors (GR), and compounds modulating these receptors show promise in mitigating metabolic and cardiovascular-related phenotypes. CORT118335 (GR/MR modulator) prevents high-fat diet-induced weight gain and adiposity in mice, but the ability of this compound to reverse obesity-related symptoms is unknown. Adult male rats were subcutaneously administered CORT118335 (3, 10, or 30 mg/kg) or vehicle once daily. A 5-day treatment with CORT118335 at 30 mg/kg induced weight loss in rats fed a chow diet by decreasing food intake. However, lower doses of the compound attenuated body weight gain primarily because of decreased calorific efficiency, as there were no significant differences in food intake compared with vehicle. Notably, the body weight effects of CORT118335 persisted during a 2-wk treatment hiatus, suggesting prolonged effects of the compound. To our knowledge, we are the first to demonstrate a sustained effect of combined GR/MR modulation on body weight gain. These findings suggest that CORT118335 may have long-lasting effects, likely due to GR/MR-induced transcriptional changes. Prolonged (18 days) treatment of CORT118335 (10 mg/kg) reversed body weight gain and adiposity in animals fed a high-fat diet for 13 wk. Surprisingly, this occurred despite a worsening of the lipid profile and glucose homeostasis as well as a disrupted diurnal corticosterone rhythm, suggesting GR agonistic effects in the periphery. We conclude that species and tissue-specific targeting may result in promising leads for exploiting the metabolically beneficial aspects of GR/MR modulation.


2007 ◽  
Vol 293 (5) ◽  
pp. R1855-R1863 ◽  
Author(s):  
Christine Mack ◽  
Julie Wilson ◽  
Jennifer Athanacio ◽  
James Reynolds ◽  
Kevin Laugero ◽  
...  

The ability of amylin to reduce acute food intake in rodents is well established. Longer-term administration in rats (up to 24 days) shows a concomitant reduction in body weight, suggesting energy intake plays a significant role in mediating amylin-induced weight loss. The current set of experiments further explores the long-term effects of amylin (4–11 wk) on food preference, energy expenditure, and body weight and composition. Furthermore, we describe the acute effect of amylin on locomotor activity and kaolin consumption to test for possible nonhomeostatic mechanisms that could affect food intake. Four-week subcutaneous amylin infusion of high-fat fed rats (3–300 μg·kg−1·day−1) dose dependently reduced food intake and body weight gain (ED50for body weight gain = 16.5 μg·kg−1·day−1). The effect of amylin on body weight gain was durable for up to 11 wks and was associated with a specific loss of fat mass and increased metabolic rate. The body weight of rats withdrawn from amylin (100 μg·kg−1·day−1) after 4 wks of infusion returned to control levels 2 wks after treatment cessation, but did not rebound above control levels. When self-selecting calories from a low- or high-fat diet during 11 wks of infusion, amylin-treated rats (300 μg·kg−1·day−1) consistently chose a larger percentage of calories from the low-fat diet vs. controls. Amylin acutely had no effect on locomotor activity or kaolin consumption at doses that decreased food intake. These results demonstrate pharmacological actions of amylin in long-term body weight regulation in part through appetitive-related mechanisms and possibly via changes in food preference and energy expenditure.


Endocrinology ◽  
2014 ◽  
Vol 155 (11) ◽  
pp. 4189-4201 ◽  
Author(s):  
Jordi Altirriba ◽  
Anne-Laure Poher ◽  
Aurélie Caillon ◽  
Denis Arsenijevic ◽  
Christelle Veyrat-Durebex ◽  
...  

Abstract Oxytocin has been suggested as a novel therapeutic against obesity, because it induces weight loss and improves glucose tolerance in diet-induced obese rodents. A recent clinical pilot study confirmed the oxytocin-induced weight-reducing effect in obese nondiabetic subjects. Nevertheless, the mechanisms involved and the impact on the main comorbidity associated with obesity, type 2 diabetes, are unknown. Lean and ob/ob mice (model of obesity, hyperinsulinemia, and diabetes) were treated for 2 weeks with different doses of oxytocin, analogues with longer half-life (carbetocin) or higher oxytocin receptor specificity ([Thr4,Gly7]-oxytocin). Food and water intake, body weight, and glycemia were measured daily. Glucose, insulin, and pyruvate tolerance, body composition, several hormones, metabolites, gene expression, as well as enzyme activities were determined. Although no effect of oxytocin on the main parameters was observed in lean mice, the treatment dose-dependently reduced food intake and body weight gain in ob/ob animals. Carbetocin behaved similarly to oxytocin, whereas [Thr4,Gly7]-oxytocin (TGOT) and a low oxytocin dose decreased body weight gain without affecting food intake. The body weight gain-reducing effect was limited to the fat mass only, with decreased lipid uptake, lipogenesis, and inflammation, combined with increased futile cycling in abdominal adipose tissue. Surprisingly, oxytocin treatment of ob/ob mice was accompanied by a worsening of basal glycemia and glucose tolerance, likely due to increased corticosterone levels and stimulation of hepatic gluconeogenesis. These results impose careful selection of the conditions in which oxytocin treatment should be beneficial for obesity and its comorbidities, and their relevance for human pathology needs to be determined.


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