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Results 701 - 750 of 854
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Zittel T T - - 1998
BACKGROUND: Calcitonin gene-related peptide (CGRP) is a widely distributed neuropeptide contained in intrinsic and extrinsic neurons of the gastrointestinal wall that has been shown to be released by noxious stimulation, to be involved in nociception, to inhibit gastrointestinal motility, and to partly mediate postoperative gastric ileus. We hypothesized that abdominal ...
Mercer J G - - 1998
Food deprivation in the laboratory rat decreases plasma leptin and insulin, elevates glucocorticoid concentration, and increases the activity of the neuropeptide Y (NPY) system and feeding drive. In contrast, Syrian hamsters fail to modify feeding behaviour in response to various food scarcity paradigms. Two components of the neuroendocrine-hormonal response to ...
Jahng J W - - 1998
The anorexia (anx) mutation causes reduced food intake in preweanling mice, resulting in death from starvation within 3-4 weeks. In wild-type rodents, starvation induces increased neuropeptide Y (NPY) mRNA levels in the arcuate nucleus that promotes compensatory hyperphagia. Despite severely decreased body weight and food intake at 3-weeks age, anx/anx ...
Dryden S - - 1998
To evaluate the role of neuropeptide Y (NPY), a potent appetite stimulant, in controlling food intake and body weight, we investigated the use of antisense oligodeoxynucleotides (ODNs) to inhibit NPY gene expression in the hypothalamus. We compared the hypothalamic distribution of fluorescein-labelled ODNs administered intracerebroventricularly, and effects on food intake ...
Marín Bivens C L - - 1998
Although hypothalamic injections of neuropeptide Y (NPY) induce robust feeding, there is little information about the patterns of feeding elicited by this peptide. To reveal these patterns, NPY (0, 8, 24, 78, 235 pmol/10 nl) was injected into the perifornical hypothalamus (PFH) of satiated adult male rats and their subsequent ...
Beck B - - 1998
Neuropeptide Y (NPY) and leptin are actually two of the most potent peptides involved in the regulation of food intake with their respective stimulatory and inhibitory actions. The infusion of each peptide has a significant influence on the mRNA expression of the other in the adipose tissue for leptin and ...
Morovat A - - 1998
Understanding the interactions between metabolic signals that regulate insulin-like growth factor-I (IGF-I) is crucial to a recognition of mechanisms that control mammalian growth. Thyroid hormones (THs) are essential for normal growth and development, and it has been suggested previously that they can modify circulating IGF-I concentrations. However, the fact that ...
Horn C C - - 1998
Injection of the fructose analogue, 2,5-anhydro-D-mannitol (2,5-AM), stimulates eating behavior in rats. Previous studies have shown that administration of 2,5-AM in doses that elicit eating induces Fos-like immunoreactivity (Fos-li) primarily in hindbrain structures, including the nucleus of the solitary tract (NTS), area postrema (AP), and lateral parabrachial nucleus (PBN). To ...
Cummings S L - - 1998
Neuropeptides affect food intake via peripheral and brainstem mechanisms, but their roles in mediating feeding via the cerebral cortex have received little attention. The anterior piriform cortex (APC) appears to play a critical role in neuroperception of deficiencies of essential amino acids (AA) and the anorectic response to such deficiencies. ...
Gomez F - - 1997
Arginine vasopressin (AVP) produced in the hypothalamic suprachiasmatic nuclei (SCN) plays a role in establishing neuroendocrine rhythms and, in particular, in regulating the corticotrope axis rhythm. It has recently been shown that AVP from SCN inhibits corticosteroid release. In order to investigate the influence of suprachiasmatic AVP on the different ...
Rybkin I I - - 1997
Three experiments were conducted to investigate the effect of restraint stress applied at different times of the light-dark cycle on feeding behavior and body weight of rats. Sprague-Dawley rats were restrained for 3 h in restraining tubes either at the start or the end of the light cycle. There was ...
Broberger C - - 1997
Neuropeptide Y is one of the most powerful neurochemical stimulants of food intake known. The neuronal substrate for this action is believed to be the neuropeptide Y-expressing cell population in the hypothalamic arcuate nucleus. In this study, mice homozygous for the anorexia mutation (anx) were investigated histochemically; anx is a ...
Pomonis J D - - 1997
Neuropeptide Y (NPY) is a powerful inducer of food intake with a key site of action in the paraventricular nucleus (PVN) of the hypothalamus. An effective method for inhibiting the effects of NPY is pretreatment with the opioid antagonists naloxone or naltrexone. In the present study, we used immunohistochemistry for ...
Galef BG - - 1997
The influence of both social and asocial factors on the stability of a socially learned tradition of food preference was explored in colonies of domesticated Norway rats, Rattus norvegicusWe trained members of 'founding colonies' of rats to avoid eating a distinctively flavoured food and then introduced them into enclosures where ...
Wolf G - - 1997
Leptin, the circulating protein that inhibits food intake and energy expenditure, was thought to function through inhibition of the hypothalamic neuropeptide Y (NPY), a stimulator of food intake. However, mouse mutants lacking NPY are normal, suggesting that alternative neuromodulators of food intake must exist. Recently, melanocortin, a neuropeptide acting on ...
Wilding J P - - 1997
Neuropeptide Y (NPY) is the most powerful appetite stimulant known, and rates of synthesis and release in the hypothalamus correlate closely with nutritional status. Pregnancy and lactation provide an excellent model of physiological hyperphagia. In this study the authors measured food intake, plasma glucose, insulin and luteinizing hormone (LH) and ...
Cabanac M - - 1997
We studied the influence of acute intracerebroventricular (i.c.v.) NPY on the relation existing in the rat between food-hoarding behavior and the body weight of the animals. Six male rats were trained to feed every day from 1000 to 1200 h. Then, their threshold for the onset of food hoarding was ...
Grebe T A - - 1996
We report on a two-generation family exhibiting dominant inheritance of complex polysyndactyly associated with hypothalamic hamartoma. These individuals have some manifestations of Pallister-Hall syndrome (PHS), but their phenotype is milder. The proposita is a 16-year-old girl with polysyndactyly of the hands and feet, short stature, and a large hypothalamic hamartoma. ...
Forbes J M - - 1996
Numerous factors have the potential to affect the amount of forage or pasture eaten by ruminant animals, including gut capacity, ability of tissues to metabolize nutrients, ruminal acidity, and osmolality. Much research into the control of food intake has tested one particular theory, often by applying greater degrees of stimulation ...
Lopez-Valpuesta F J - - 1996
The central actions of neuropeptide Y antisense oligodeoxynucleotide (aNPY) and NPY-Y1 receptor antisense (aNPY-Y1) on body temperature (Tb), feeding and body weight of unrestrained rats were determined by the repeated intracerebroventricular (i.c.v.) injection of 0.5 microgram doses. aNPY-Y1 caused intense phasic rises in Tb, lowered body weight and caused transient ...
Sipols A J - - 1996
In the present study, we examined the ability of the orexigenic peptide neuropeptide Y (NPY) to stimulate feeding when administered into the lateral ventricle of baboons. No increase of either meal size or total daily food intake was observed over the dose range tested (1-30 micrograms). These results suggest that, ...
Seeley R J - - 1996
The suppression of food intake after a period of forced overfeeding is potent and long lasting, yet little is known of the underlying mechanisms for this regulatory response. Rats were overfed via a surgically implanted gastrostomy tube. During overfeeding, plasma insulin and corticotropin-releasing hormone (CRH) mRNA in the paraventricular nucleus ...
Choi S J - - 1996
Cobalt protoporphyrin (CoPP) reduces food intake and body weight following intracerebroventricular (i.c.v.) administration in rats. We injected 0.2 mumol CoPP per kg body weight i.c.v. and monitored body weight and daily food intake for 7 days. The body weight and 24 h food intake of CoPP-treated animals was significantly lower ...
Matos F F - - 1996
Administration of neuropeptide Y (NPY) into hypothalamic areas or into the cerebral ventricles induces marked increases in food consumption in satiated rats. Since monoamines have been suggested to be involved in NPY-induced feeding, we investigated the effects of NPY and [D-Trp32]NPY, a putative NPY antagonist, on extracellular levels of norepinephrine ...
Yoshihara T - - 1996
Extracellular neuropeptide Y (NPY) in the vicinity of the paraventricular nucleus (PVN) as well as NPY concentrations in the PVN were measured in rats under ad libitum feeding and 2-day and 10-day food deprivation. Plasma corticosterone levels were not changed by 2-day food deprivation but were increased by subsequent refeeding. ...
Lemos F J - - 1996
The effects of age and food composition on the expression of trypsin and aminopeptidase genes in the Anopheles gambiae gut were investigated. No trypsin mRNA was detected in the gut of newly eclosed females, but this mRNA accumulated to relatively high levels within the first day of life. In contrast, ...
Kotz C M - - 1996
Neuropeptide Y (NPY) has potent effects on several components of energy metabolism, including increased feeding and decreased brown fat thermogenesis. Negative energy balance, such as food deprivation, increases NPY mRNA in hypothalamic arcuate nucleus (ARC). Naltrexone (NLTX), an opioid receptor antagonist, decreases NPY-induced feeding. We hypothesized that NLTX would alter ...
Mercer J G - - 1996
Because the Syrian hamster, Mesocricetus auratus, does not increase food intake in response to food deprivation, we investigated whether hypothalamic NPY gene expression in this species was sensitive to this imposed state of negative energy balance. In the rat, food deprivation for 48 h resulted in a 150% increase in ...
Erickson J C - - 1996
Neuropeptide Y (NPY), a 36-amino-acid transmitter distributed throughout the nervous system, is thought to function as a central stimulator of feeding behaviour. NPY has also been implicated in the modulation of mood, cerebrocortical excitability, hypothalamic-pituitary signalling, cardiovascular physiology and sympathetic function. However, the biological significance of NPY has been difficult ...
Yoshihara T - - 1996
The neuronal system responsible for the release of neuropeptide Y (NPY) in the paraventricular nucleus (PVN) was examined in rats under food deprivation and restricted daily feeding (RF). The ascending noradrenergic bundle (NAB) of neurons from the brain stem were destructed by microinjection of 6-hydroxydopamine (6-OHDA), and the extracellular NPY ...
Dryden S - - 1996
To determine whether NPY and 5-HT interact, we studied the effects on hypothalamic NPY and NPY mRNA levels of acute (10 mg/kg) and 7-day administration (10 mg/kg/day) of mCPP (a 5-HT 1B/2C agonist) and flesinoxan (a 5-HT 1A agonist). After both treatments, mCPP reduced food intake and NPY levels in ...
Boss-Williams K A - - 1996
Siberian hamsters (phodopus sungorus sungorus) show naturally occurring seasonal cycles of food intake that are triggered by changes in the photoperiod. In long "summer-like" days (LD) food intake is at its peak, whereas in short "winter-like" days (SD) food intake reaches a nadir. Although the mechanisms underlying these changes in ...
Cangiano C - - 1996
During tumor growth, anorexia and reduced food intake markedly contribute to the development of malnutrition, thus worsening overall patients' survival. A better understanding of the pathophysiology of eating behavior may lead to new and more effective therapies, aiming at counteracting the detrimental effects of anorexia and reduced food intake on ...
Komenami N - - 1995
We investigated the effect of chronic infusion of neuropeptide Y (NPY) aimed at the hypothalamic suprachiasmatic nucleus (SCN) or the lateral cerebral ventricle (LCV) on food intake. The experiments were performed in adult male Wistar rats infused for 7 days with saline or NPY (10 and 100 pmol microliters-1 h-1) ...
Mercer J G - - 1995
Two catabolic states leading to loss of body weight were compared in the Djungarian hamster (Phodopus sungorus campbelli). Hypothalamic neuropeptide Y (NPY) and gene expression for NPY and corticotropin-releasing factor (CRF) were examined after withdrawal of food for 48 h or exposure to short photoperiod for 10 or 20 wk. ...
Bray G A - - 1995
Many peptides have been shown to modulate nutrient intake. In most cases, these peptides decrease food intake, but in a few cases they have been demonstrated to stimulate feeding. Infusion of insulin peripherally will decrease food intake unless hypoglycemia occurs where the reduced glucose is a stimulus to feeding. Other ...
Frankish H M - - 1995
Neuropeptide Y (NPY) is synthesized in arcuate (ARC) neurons which project principally to the paraventricular nucleus (PVN). NPY injected into the PVN causes hyperphagia, reduced energy expenditure and eventually obesity, effects which are opposed by nicotine. We aimed to investigate whether nicotine's effects on energy balance might be mediated by ...
Sellami S - - 1995
Interleukin-1beta (IL-1beta ) has anorectic, hyperthermic, and analgesic or hyperalgesic (depending on the studies) effects in the rat. These effects appear to be mediated by the central nervous system; however, the exact localization of action of IL-1beta in the brain has never been delineated with precision. The purpose of this ...
Hagan M M - - 1995
Peptide YY (PYY) administered centrally in rats induces powerful overeating. PYY also occurs endogenously in humans and is elevated in abstaining bulimic patients. To examine the effect of PYY in an environment that parallels some aspects of bulimia, rats were tested in a paradigm associated with approach-avoidance behavior, choosing a ...
Richardson R D - - 1995
To determine if altered sensitivity to neuropeptide Y (NPY) underlies premigratory fattening, white-crowned sparrows held on short day length (9:15-h light-dark) received injections into the third ventricle (ivt) of saline or several doses of NPY. An inverted-U function occurred with food intake increasing 30 and 60 min after doses of ...
Burlet A - - 1995
Neuropeptide Y is demonstrated as a potent orexigenic peptide when injected into the rat hypothalamic paraventricular nuclei. The neuropeptide Y innervation of paraventricular nuclei originates from both hypothalamic arcuate nuclei and brainstem neurons, whose specific role in the control of food intake is still under discussion. To assess the role ...
Upreti R K - - 1995
Regulation of hunger and satiety is a complex process thought to be controlled by a complex interplay of neurotransmitters in the hypothalamic region of the brain. Reduced food intake or anorexia has also been observed under various disease or disorder conditions including AIDS and cancer. On the other hand, increased ...
Hanson E S - - 1995
Neuropeptide Y (NPY) is a powerful stimulus to food intake in the rat. Exogenous NPY given into the third ventricle or into the paraventricular nucleus (PVN) of the hypothalamus stimulates both food consumption as well as the hypothalamus-pituitary-adrenal (HPA) axis. Presumably NPY activates the adrenocortical system through direct stimulation of ...
Yettefti K - - 1995
Extracellular single-unit recordings have been carried out in the caudal part of the nucleus tractus solitarius of male rats anesthetized by i.v. infusion with Ketamine. The sensitivity of 38 cells to 0.2 ml of 0.55 M glucose i.v. administration has been studied. The spike frequency of 75% of these cells ...
Mock D W - - 1995
In choosing how many offspring to rear per cycle, parents commonly starts with more than they really can afford, then allow/encourage some to die. Multiple incentives for overproduction exist. By creating marginal young, parents may: (1) capitalize when unpredictable resources prove unusually rich; (2) supply these as food or servants ...
Bouali S M - - 1995
Because thermoregulation and food consumption are interrelated, and because thermoregulation processes are influenced by ambient temperature, we examined the effects of neuropeptide Y (NPY) on both body temperature and food intake in various thermal environments after intracerebroventricular administration of 20 micrograms. Results reveal that the prominent effects of NPY on ...
Seeley R J - - 1995
Neuropeptide Y (NPY) has a potent orexigenic effect when administered either into the third ventricle or directly into hypothalamic nuclei, but the mechanism by which NPY increases intakes is poorly understood. The present study tested the ability of NPY to increase intake of the rat in the intraoral intake test, ...
Jolicoeur F B - - 1995
The objective of the present study was to identify hypothalamic sites that might be implicated in the effects of neuropeptide Y (NPY) on both body temperature and food intake. For this purpose, the effects of direct microinjections of NPY in several doses (0.156-20 micrograms) into discrete hypothalamic nuclei on body ...
O'Shea R D - - 1995
The role of neuropeptide Y (NPY) in the central control of appetite and energy balance is now established, but its involvement in the control of drinking and fluid homeostasis is less well characterized. Central administration of NPY stimulates drinking in rats, an effect believed to be independent of its orexigenic ...
Bouali S M - - 1995
Our previous in vivo structure-activity studies suggested that the putative receptors mediating the effects of NPY and NPY2-36 on food intake and body temperature are pharmacologically different [17]. In the present study, we examined and compared dose-related effects of NPY and NPY2-36 on ad lib food intake and rectal temperature ...
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