scholarly journals Changes in Hypothalamic Corticotropin-Releasing Hormone, Neuropeptide Y, and Proopiomelanocortin Gene Expression during Chronic Rapid Eye Movement Sleep Deprivation of Rats

Endocrinology ◽  
2006 ◽  
Vol 147 (1) ◽  
pp. 421-431 ◽  
Author(s):  
Michael Koban ◽  
Wei Wei Le ◽  
Gloria E. Hoffman

Chronic rapid eye movement (paradoxical) sleep deprivation (REM-SD) of rats leads to two conspicuous pathologies: hyperphagia coincident with body weight loss, prompted by elevated metabolism. Our goals were to test the hypotheses that 1) as a stressor, REM-SD would increase CRH gene expression in the hypothalamus and that 2) to account for hyperphagia, hypothalamic gene expression of the orexigen neuropeptide Y (NPY) would increase, but expression of the anorexigen proopiomelanocortin (POMC) would decrease. Enforcement of REM-SD of adult male rats for 20 d with the platform (flowerpot) method led to progressive hyperphagia, increasing to approximately 300% of baseline; body weight steadily declined by approximately 25%. Consistent with changes in food intake patterns, NPY expression rapidly increased in the hypothalamic arcuate nucleus by d 5 of REM-SD, peaking at d 20; by contrast, POMC expression decreased progressively during REM-SD. CRH expression was increased by d 5, both in mRNA and ability to detect neuronal perikaryal staining in paraventricular nucleus with immunocytochemistry, and it remained elevated thereafter with modest declines. Taken together, these data indicate that changes in hypothalamic neuropeptides regulating food intake are altered in a manner consistent with the hyperphagia seen with REM-SD. Changes in CRH, although indicative of REM-SD as a stressor, suggest that the anorexigenic actions of CRH are ineffective (or disabled). Furthermore, changes in NPY and POMC agree with current models of food intake behavior, but they are opposite to their acute effects on peripheral energy metabolism and thermogenesis.

2021 ◽  
pp. 113464
Author(s):  
Mitchell A. Head ◽  
Allen S. Levine ◽  
David G. Christian ◽  
Anica Klockars ◽  
Pawel K. Olszewski

2001 ◽  
Vol 280 (4) ◽  
pp. R1052-R1060 ◽  
Author(s):  
Cynthia A. Blanton ◽  
Barbara A. Horwitz ◽  
James E. Blevins ◽  
Jock S. Hamilton ◽  
Eduardo J. Hernandez ◽  
...  

The anorexia of aging syndrome in humans is characterized by spontaneous body weight loss reflecting diminished food intake. We reported previously that old rats undergoing a similar phenomenon of progressive weight loss (i.e., senescent rats) also display altered feeding behavior, including reduced meal size and duration. Here, we tested the hypothesis that blunted responsiveness to neuropeptide Y (NPY), a feeding stimulant, occurs concurrently with senescence-associated anorexia/hypophagia. Young (8 mo old, n = 9) and old (24–30 mo old, n = 11) male Fischer 344 rats received intracerebroventricular NPY or artificial cerbrospinal fluid injections. In response to a maximum effective NPY dose (10 μg), the net increase in size of the first meal after injection was similar in old weight-stable (presenescent) and young rats (10.85 ± 1.73 and 12.63 ± 2.52 g/kg body wt0.67, respectively). In contrast, senescent rats that had spontaneously lost ∼10% of body weight had significantly lower net increases at their first post-NPY meal (1.33 ± 0.33 g/kg body wt0.67) than before they began losing weight. Thus altered feeding responses to NPY occur in aging rats concomitantly with spontaneous decrements in food intake and body weight near the end of life.


Endocrinology ◽  
1998 ◽  
Vol 139 (2) ◽  
pp. 466-473 ◽  
Author(s):  
B. Xu ◽  
M. G. Dube ◽  
P. S. Kalra ◽  
W. G. Farmerie ◽  
A. Kaibara ◽  
...  

Abstract Although ciliary neurotropic factor (CNTF) is a tropic factor in nervous system development and maintenance, peripheral administration of this cytokine also causes severe anorexia and weight loss. The neural mechanism(s) mediating the loss of appetite is not known. As hypothalamic neuropeptide Y (NPY) is a potent orexigenic signal, we tested the hypothesis that CNTF may adversely affect NPYergic signaling in the hypothalamus. Intraperitoneal administration of CNTF (250μ g/kg) daily for 4 days significantly suppressed 24-h food intake in a time-dependent manner and decreased body weight. The loss in body weight was similar to that which occurred in pair-fed (PF) rats. As expected, hypothalamic NPY gene expression, determined by measurement of steady state prepro-NPY messenger RNA by ribonuclease protection assay, significantly increased in PF rats in response to energy imbalance. However, despite a similar loss in body weight, there was no increase in NPY gene expression in CNTF-treated rats. Daily administration of CNTF intracerebroventricularly (0.5 or 5.0 μg/rat) also produced anorexia and body weight loss. In this experiment, negative energy balance produced by both PF and food deprivation augmented hypothalamic NPY gene expression. However, despite reduced intake and loss of body weight, no similar increment in hypothalamic NPY gene expression was observed in CNTF-treated rats. In fact, in rats treated with higher doses of CNTF (5.0 μg/rat), NPY gene expression was reduced below the levels seen in control, freely fed rats. Furthermore, CNTF treatment also markedly decreased NPY-induced feeding. These results suggested that anorexia in CNTF-treated rats may be due to a deficit in NPY supply and possibly in the release and suppression of NPY-induced feeding. The possibility that CNTF-induced anorexia may be caused by increased leptin was next examined. Daily intracerebroventricular injections of leptin (7 μg/rat) decreased food intake, body weight, and hypothalamic NPY gene expression in a manner similar to that seen after CNTF treatment. Leptin administration also suppressed NPY-induced feeding. However, peripheral and central CNTF injections markedly decreased leptin messenger RNA in lipocytes, indicating a deficiency of leptin in these rats; thus, leptin was unlikely to be involved in appetite suppression. Thus, these results show that a two-pronged central action of CNTF, causing diminution in both NPY availability and the NPY-induced feeding response, may underlie the severe anorexia. Further, unlike other members of the cytokine family, suppression of NPYergic signaling in the hypothalamus by CNTF does not involve up-regulation of leptin, but may involve a direct action on hypothalamic NPY neurons or on neural circuits that regulate NPY signaling in the hypothalamus.


2015 ◽  
Vol 308 (1) ◽  
pp. E40-E50 ◽  
Author(s):  
Beatriz de Carvalho Borges ◽  
Rodrigo C. Rorato ◽  
Ernane Torres Uchoa ◽  
Paula B. Marangon ◽  
Carol F. Elias ◽  
...  

Leptin resistance is induced by the feedback inhibitors tyrosine phosphatase-1B (PTP1B) and decreased Src homology 2 domain-containing tyrosine phosphatase-2 (SHP-2) signaling. To investigate the participation of PTP1B and SHP-2 in LPS-induced leptin resistance, we injected repeated (6-LPS) intraperitoneal LPS doses (100 μg/kg ip) for comparison with a single (1-LPS) treatment and evaluated the expression of SHP-2, PTP1B, p-ERK1/2, and p-STAT3 in the hypothalamus of male Wistar rats. The single LPS treatment increased the expression of p-STAT3 and PTP1B but not SHP-2. The repeated LPS treatment reduced SHP-2, increased PTP1B, and did not change p-STAT3. We observed that the PTP1B expression induced by the endotoxin was highly colocalized with leptin receptor cells in the hypothalamus of LepRb-IRES-Cre-tdTomato reporter mice. The single, but not the repeated, LPS treatment decreased the food intake and body weight. Leptin had no stimulatory effect on the hypophagia, body weight loss, or pSTAT3 expression in 6-LPS rats, indicating leptin unresponsiveness. Notably, the PTP1B inhibitor (3.0 nmol/rat in 5 μl icv) restored the LPS-induced hypophagia in 6-LPS rats and restored the ability of leptin to reduce food intake and body weight as well as to phosphorylate STAT3 in the arcuate, paraventricular, and ventromedial nuclei of the hypothalamus. The present data suggest that an increased PTP1B expression in the hypothalamus underlies the development of leptin resistance during repeated exposure to LPS. Our findings contribute to understanding the mechanisms involved in leptin resistance during low-grade inflammation as seen in obesity.


2014 ◽  
Vol 25 (10) ◽  
pp. 991-996 ◽  
Author(s):  
Diana Sánchez-Hernández ◽  
Clara E. Cho ◽  
Ruslan Kubant ◽  
Sandra A. Reza-López ◽  
Abraham N. Poon ◽  
...  

2006 ◽  
Vol 291 (2) ◽  
pp. R473-R480 ◽  
Author(s):  
E. Szentirmai ◽  
J. M. Krueger

Neuropeptide Y (NPY) is a well-characterized neuromodulator in the central nervous system, primarily implicated in the regulation of feeding. NPY, orexins, and ghrelin form a hypothalamic food intake regulatory circuit. Orexin and ghrelin are also implicated in sleep-wake regulation. In the present experiments, we studied the sleep-modulating effects of central administration of NPY in rats. Rats received intracerebroventricular injection of physiological saline or three different doses of NPY (0.4, 2, and 10 μg in a volume of 4 μl) at light onset. Another group of rats received bilateral microinjection of saline or 2 μg NPY in the lateral hypothalamus in a volume of 0.2 μl. Sleep-wake activity and motor activity were recorded for 23 h. Food intake after the control and treatment injections was also measured on separate days. Intracerebroventricular and lateral hypothalamic administration of NPY suppressed non-rapid-eye-movement sleep and rapid-eye-movement sleep in rats during the first hour after the injection and also induced changes in electroencephalogram delta power spectra. NPY stimulated food intake in the first hour after both routes of administration. Data are consistent with the hypothesis that NPY has a role in the integration of feeding, metabolism, and sleep regulation.


2004 ◽  
Vol 24 (8) ◽  
pp. 659-669 ◽  
Author(s):  
Monika Leonhardt ◽  
Sabine Münch ◽  
Margriet Westerterp-Plantenga ◽  
Wolfgang Langhans

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2195
Author(s):  
Ester Arévalo Sureda ◽  
Xuemei Zhao ◽  
Valeria Artuso-Ponte ◽  
Sophie-Charlotte Wall ◽  
Bing Li ◽  
...  

Isoquinoline alkaloids (IQ) exert beneficial antimicrobial and anti-inflammatory effects in livestock. Therefore, we hypothesized that supplementing sows’ diets with IQ during gestation would decrease farrowing stress, affecting the piglets’ development and performance. Sows were divided into: IQ1, supplemented with IQ from gestation day 80 (G80) to weaning; IQ2, supplemented from gestation day 110 (G110) to weaning, and a non-supplemented (NC) group. Sow body weight (BW), feed intake, back-fat thickness and back-muscle thickness were monitored. Cortisol, glucose and insulin were measured in sows’ blood collected 5 d before, during, and after 7 d farrowing. Protein, fat, IgA and IgG were analyzed in the colostrum and milk. Piglets were monitored for weight and diarrhea score, and for ileum histology and gene expression 5 d post-weaning. IQ-supplemented sows lost less BW during lactation. Glucose and insulin levels were lower in the IQ groups compared to NC-sows 5 d before farrowing and had higher levels of protein and IgG in their colostrum. No other differences were observed in sows, nor in the measured parameters in piglets. In conclusion, IQ supplementation affected sows’ metabolism, reducing body weight loss during lactation. Providing IQ to sows from their entrance into the maternity barn might be sufficient to induce these effects. IQ improved colostrum quality, increasing the protein and IgG content, improving passive immunity for piglets.


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