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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Molecular and cellular mechanisms of the interrelations between the feeding and defense behaviour were studied in a snail Helix lucorum. The dynamics of defense reactions was investigated in snails with different levels of feeding motivation. Defense reactions were suppressed in hungry snails, while 15-20 min after the beginning of food intake they were facilitated. The facilitation depended on a duration of starvation. Injection of 0.5 ml of 5 mM glucose solution (up to the glucose level in the haemolymph of a food satiated snail, 1.6-2.0 mM) or injections of 20-30 ng of synthetic analogues of the gastrointestinal peptides (pentagastrin of octapeptide cholecystokinin, CCK-8) facilitated the defense reaction in a hungry snail. Parameters of the facilitation were similar to those in the period of food intake. Activity of the command neurons of defense behaviour (L-PPL1) after the carrot juice application to the lip of a semi-intact preparation from a hungry snail was glucose-dependent. Similar glucose-dependent changes of L-PPL1 activity were found after CCK-8, but not FMRFamide application during the perfusion with 0.5 mM glucose. L-PPL1, but not L-PPa2-3 neurons were most sensitive to glucose and CCK-8 level changes in the Ringer solution. Adaptive significance of the behavioural phenomena as well as glucose and gastrin/CCK-like peptide participation in these processes are discussed.
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PMID:[The facilitation of defensive reactions during food consumption in the snail helix: the participation of glucose and gastrin/cholecystokinin-like peptide]. 128 84

Anorexia nervosa (AN) is a syndrome of unknown cause characterized by voluntary starvation. Cholecystokinin has been implicated as a neuroendocrine regulatory factor in control of satiety. Relatively little information is known about gastrointestinal hormone responses to feeding in subjects with anorexia nervosa. In the present studies, we examine fasting and postprandial levels of cholecystokinin (CCK), vasoactive intestinal peptide (VIP) and peptide histidine methionine (PHM) in anorexia nervosa subjects and in control individuals. Results of these studies indicate that plasma CCK response to a liquid meal (Ensure Plus) in untreated AN subjects was distinctly different from that observed in healthy controls, both in terms of temporal pattern of peptide released and the amount of CCK secreted into the circulation. Peak levels of CCK release occurred at 30 min following meal ingestion in AN patients and at 60 min in control subjects. Integrated CCK release in untreated AN patients was approximately twice that measured in control individuals. Renutrition therapy was associated with reversion of the pattern of CCK release to that observed in control subjects. Plasma VIP levels were unchanged following meal ingestion in both control and anorexic subjects. In contrast, PHM levels in AN subjects were significantly greater than that observed in control individuals. The pattern of PHM release following liquid meal ingestion was similar to that observed with plasma CCK; namely, peak release of peptide was observed at 30 min which was significantly greater than corresponding control values (P less than 0.05). In conclusion, these results demonstrate distinctive differences in plasma CCK and PHM levels in response to feeding in AN subjects when compared to control individuals. These findings suggest that the earlier and greater rise in plasma CCK levels in AN subjects following meal ingestion may contribute to the abnormal sensation of satiety in this condition.
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PMID:Cholecystokinin, vasoactive intestinal peptide and peptide histidine methionine responses to feeding in anorexia nervosa. 179 80

The effects of starvation on the tissue concentrations of some peptides common to the gastrointestinal tract and the central nervous system have been examined. Groups of 6 rats were either fed ad libitum or starved for up to 4 days and killed by decapitation. Antrum, fundus, duodenum, jejunum, ileum, colon, pancreas and brain were dissected, weighed and then frozen on dry ice. The tissues were extracted sequentially in boiling water and 3% acetic acid, centrifuged and the supernatants radioimmunoassayed for gastrin, cholecystokinin (CCK), vasoactive intestinal peptide (VIP), gastric inhibitory peptide (GIP) and somatostatin. Each peptide was not assayed in each tissue. Starvation had no effect on the concentrations of peptides measured in the fundus (somatostatin and VIP), ileum (somatostatin, GIP, VIP) and colon (somatostatin, GIP, VIP). VIP concentration was increased in the jejunum and GIP was increased in both the duodenum and jejunum. Antral gastrin was the only peptide in the gastrointestinal tract to be decreased by food deprivation. Somatostatin concentration was approximately doubled in the antrum, duodenum, jejunum and pancreas. Brain VIP was unchanged. Brain somatostatin and CCK were significantly reduced by starvation. We conclude that starvation results in organ-specific and hormone-specific alterations in tissue concentrations of peptides of the gastrointestinal tract and the central nervous system.
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PMID:Starvation in the rat: effect on peptides of the gut and brain. 614 Sep 13

Modulation of feeding by opiates, putative satiety peptides, and dopamine was explored in the Chinese hamster, an animal that develops diabetes mellitus in certain inbred strains. Diabetic hamsters were hyperphagic relative to their nondiabetic controls, but both groups exhibited natural circadian variation in feeding. Starvation provoked hyperphagia of about 1-h duration in both groups. Naloxone and butorphanol had no effects on Chinese hamster feeding. Opiate receptor binding on Chinese hamster brains demonstrated no specific binding of naloxone or ethylketocyclazocine, but IR-dynorphin concentrations were comparable with that in rats. N-allylnormetazocine, a sigma-opiate receptor agonist, appeared to stimulate diabetic hamster feeding. Peptides reputed to have satiety effects in rats were without effect in Chinese hamsters: cholecystokinin, bombesin, somatostatin, and pancreatic polypeptide. Calcitonin limited feeding in both groups but may be nonspecific. Dopaminergic blockade by haloperidol also limited feeding, and diabetic hamsters were more sensitive to this. Although Chinese hamsters clearly can modulate their food intake when diabetic, we conclude that the opiatergic and peptidergic influences on feeding are very different from those in rats and may be of little importance.
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PMID:Feeding systems in Chinese hamsters. 614 21

The nature and mechanism of the pancreatic exocrine dysfunction in diabetes mellitus were evaluated in vitro using isolated pancreatic acini prepared from streptozotocin-induced diabetic rats. The content of amylase and ribonuclease in diabetic acini was approximately 0.5 and 50% of the normal content, respectively. Further, reduced amounts of both enzymes were secreted by diabetic acini in response to both cholecystokinin (CCK) and carbamylcholine. However, when enzyme secretion was normalized relative to initial acinar contents, both normal and diabetic acini released enzymes at a comparable maximal rate. The time course of the release of these enzymes, and newly synthesized protein were similar in both acini. In normal acini, the effect of CCK was maximal at a concentration of 100 pM; higher concentrations led to submaximal enzyme release. The dose-response curve in diabetic acini was similarly shaped, but shifted three-fold towards higher concentration. The mobilization of cellular Ca(2+) in response to CCK was also shifted. In contrast to these results with CCK, the dose-response curve to carbamylcholine was unaltered by diabetes. The observed effects were confirmed to be due to insulin deficiency and not due to direct toxic effect of streptozotocin on acinar cells or malnutrition. Streptozotocin had no acute effect on acini when measured 24 h after administration, and alloxan, another beta cell toxin, induced similar changes in acinar enzyme content and secretory response. Moreover, the administration of exogenous insulin to diabetic rats returned the content of pancreatic amylase and the secretory response to CCK towards normal. Starvation for 48 h, although inducing a significant weight loss, did not mimic the effects of diabetes. The present studies demonstrate two major abnormalities in pancreatic exocrine secretion in the diabetic rat: (a) the content of certain digestive enzymes is markedly altered, leading to an altered amount of zymogen secretion, (b) the sensitivity to CCK is selectively reduced, most likely related to a defect in receptor activated transmembrane signaling.
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PMID:Effect of diabetes mellitus on the regulation of enzyme secretion by isolated rat pancreatic acini. 617 17

Because controversy exists as to the interpretation of the known feeding-suppressive effects of various neuropeptides, we attempted to construct a model that could differentiate satiety from other nonspecific effects. Reasoning that a satiety factor should be less inhibiting of feeding in a hungrier animal, whereas aversive agents should be unaffected by hunger, we studied the neuropharmacologic dose responses of five substances administered peripherally to rats at two different degrees of starvation. Included were four neuropeptides with putative satiety effects: cholecystokinin, calcitonin, bombesin, and pancreatic polypeptide, as well as the known aversive agent lithium chloride. In the study, cholecystokinin behaved as we postulated a satiety factor would, showing significant effect of starvation at every dose and in the ANOVA. The aversive agent lithium showed overlapping among the starvation groups and no starvation effect by ANOVA. Calcitonin failed to show differences attributable to starvation. Bombesin produced some overlapping of starvation groups and a barely significant starvation effect by ANOVA. Pancreatic polypeptide produced no feeding suppression in the rat. We conclude that cholecystokinin is a short-term satiety signal and that calcitonin acts peripherally by some nonspecific nonsatiating means. Bombesin's effects are unclear but may be nonspecific.
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PMID:Are peptides truly satiety agents? A method of testing for neurohumoral satiety effects. 666 Mar 34

Mild tail pinch (TP) in rats resulted in 72% of animals displaying ingestive behavior with 20% demonstrating gnawing behavior without food ingestion and 8% demonstrating licking behavior only. The animals ate steadily over 5 min with a maximum rate occurring at 1 min (0.5 +/- 0.2 g). There was a circadian rhythm of TP-induced behavior with the peak food ingestion occurring at 24 h. A mild increase in blood glucose occurred 120 s after commencement of TP (115 +/- 4 mg/dl). Common satiety signals such as stomach distension and glucose decreased food ingestion. Parenteral administration of glucagon, cholecystokinin-octapeptide, bombesin, and thyrotropin-releasing hormone resulted in suppression of TP-induced food ingestion. Chronic TP (12 5-min TP periods/day) resulted in a fall in spontaneous food intake with the total intake remaining similar to food intake prior to the chronic TP period. We suggest that TP serves as an excellent model for eating behavior because 1) it correlates well with starvation-induced eating; 2) it precludes the necessary deprivation of food and water to adrenalectomized animals; and 3) animals subjected to TP continue chewing in the face of decreased food intake allowing one to exclude the possibility that the effects of an anorectic are secondary to nausea.
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PMID:Stress-induced eating in rats. 719 55

It has been suggested that the long-term reproduction of the sow is best served by minimizing weight and fat loss in lactation. Such a strategy would require only a minimal restoration of weight in the following pregnancy, which would be beneficial, since the greater feed intake and weight gain in pregnancy, the greater the weight loss in lactation. Feeding ad libitum should be practised during lactation while gestation feed intake must be held low. A relationship between feed intake and embryo survival has been demonstrated in several studies, but the data are sometimes difficult to interpret. High energy feeding during the premating period and during early pregnancy, however, are often associated with increased embryo mortality. A short-term starvation in lactation decreased prolactin to post-weaning concentrations, and insulin and glucose to very low concentrations. Prolactin increased very rapidly after refeeding indicating that a neural mechanism might be involved. The increasing levels of cholecystokinin after refeeding and the neural reflex triggered might be related to this increase in prolactin. No changes in LH release were observed during the periods of starvation or refeeding. The catabolic rate during the first week of lactation is higher in sows with higher backfat thickness than in late gestation. As lactation progresses a more balanced metabolism is achieved regardless of backfat thickness before parturition. High-weight-loss primiparous sows need a longer recovery period from their negative energy balance during lactation than do low-weight-loss primiparous sows or multiparous sows. Several investigations have demonstrated that sows losing excessive amounts of body weight have extended weaning to oestrous intervals and an increase in anoestrus. Sows with low body-weight loss during lactation have higher plasma insulin and lower cortisol around weaning than do sows with high body-weight loss. What remains undefined is the degree of weight or condition loss below which an extension in the remating interval will occur and the level of dietary energy intake required to prevent this extension.
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PMID:Effects of nutrition on pregnant and lactating sows. 814 7

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 recessive mutation that causes decreased food intake and starvation, leading to death 22 days after birth. We were interested to see whether any hypothalamic neurochemical abnormalities could be detected in this genetic model of starvation. By using immunohistochemistry and in situ hybridization, the hypothalamic distributions of neuropeptide Y, cholecystokinin, galanin, and serotonin, all messenger molecules postulated to be involved in the regulation of food intake and energy metabolism, were investigated. Immunoreactivities for somatostatin, the excitatory amino acid aspartate, and acetylcholinesterase were also studied. Neuropeptide Y-like immunoreactivity was increased markedly in arcuate cell bodies and decreased in terminals in the arcuate nucleus and other hypothalamic regions of anx/anx mice compared with normal litter mates. In situ hybridization for neuropeptide Y mRNA, however, showed no significant difference in gene expression in the arcuate nucleus. In addition, immunoreactivities for aspartate, acetylcholinesterase, and somatostatin in the arcuate nucleus were decreased in anx/anx mice. For cholecystokinin, galanin, and serotonin, no certain differences in hypothalamic immunoreactivity could be seen. These data suggest that a defect in neuropeptide Y-ergic signalling in the arcuate neurons may contribute to the failure to thrive in anx/anx mice.
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PMID:Hypothalamic neurohistochemistry of the murine anorexia (anx/anx) mutation: altered processing of neuropeptide Y in the arcuate nucleus. 933 Nov 76

Cholecystokinin (CCK) and its analogues are known to exert trophic effects on the exocrine pancreas, whereas at high doses, they produce pancreatic injury. This study was carried out to study the effect of starvation on the dose-dependent pancreatotrophic effect of CCK-8 in rats. Normal or fasted rats were treated with CCK-8 doses ranging from 0.5 to 32 and 0.5 to 8 micrograms kg-1, respectively, twice daily for 5 days. Pancreatic size, protein, DNA, secretory enzyme and trypsin inhibitor (PSTI) contents as well as histology were examined. In normal rats, CCK-8 increased the pancreatic content of protein, amylase, serine proteases and PSTI with maximum values between doses of 2 and 16 micrograms kg-1. The dose of 32 micrograms kg-1, however, yielded less trophic responses. Given to fasted rats, CCK-8 increased the weight as well as protein and secretory enzyme contents of the pancreas with maximum values between doses of 1 and 4 micrograms kg-1. The first dose supramaximum for the trophic responses was as low as 8 micrograms kg-1. Histology revealed necroinflammatory damage (acinar cell vacuolization, focal cell necrosis) in the exocrine pancreas at supramaximum doses of CCK-8 in both groups. Cell necroses and vacuolization were less but present even at doses optimum for trophism and exhibited dependence on both the dose of CCK-8 and nutrition. In either the normal or fasted animals, the periinsular acini were relatively less affected by the toxic effects of CCK-8 than the teleinsular ones. The results indicate that starvation makes the exocrine pancreas more sensitive to necroinflammatory effects of CCK-8. The relative protection seen in periinsular acini suggests a modulatory influence of islet hormones on development of CCK-induced acinar cell injury.
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PMID:Dose-dependent pancreatotrophic effect of cholecystokinin-octapeptide in the rat: the influence of starvation. 963 48


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