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

The influence of food deprivation on gastric G- and D-cells and on parietal cells was studied in the rat. In fed controls and groups of rats fasted for 12 and 96 h G-, D- and parietal cell densities, somatostatin and gastrin concentration in antral and fundic specimens and serum gastrin were compared. Gastrin in antral mucosa, serum gastrin, G-cell density as well as antral D-cell density decreased in long-term fasted rats by 52%, 90%, 58% and 42%, respectively. Fundic D-cell density remained unchanged. After 96 h starvation somatostatin concentration slightly increased in antral mucosa (+35%; P less than 0.05), but decreased in fundic mucosa (-40%; P less than 0.05). Parietal cell density was not influenced by prolonged fasting. These findings demonstrate that changes in D-cell morphology and mucosal somatostatin content are not parallel and that the rat gastric D-cell is less dependent on food in the gastric lumen than the G-cell. The unaltered fundic D-cell density reflects the functional activity of gastric D-cell which has also been shown to be independent of the presence or absence of food.
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PMID:Effect of starvation on endocrine cells in the rat stomach. 287 99

Serum gastrin concentration and antral gastrin content were measured in 4-5- and 26-28-mo rats under fed conditions, after 3 days of starvation, and after 1 day of refeeding after starvation, to determine whether gastrin homeostasis is altered during aging. Gastric weight was 29% greater, but antral weight and DNA were less in the older rats. Serum gastrin fell during starvation and rose during refeeding in both groups, but it was lower in aging rats only during refeeding. Antral gastrin content in older animals was 60% of that in young rats. Starvation reduced antral gastrin only in the young, whereas refeeding lowered antral gastrin in the older animals. We conclude that, in aging rats, the relationship of serum and antral gastrin is altered during changes in food intake.
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PMID:Aging and gastrin production: changes in serum and antral gastrin concentrations in the rat. 292 71

The gastrin cells (G cells) in the rat pyloric antrum after 7, 14, 21 and 28 days of starvation were investigated by immunohistochemistry and electron microscopy. In the peroxidase anti-peroxidase method for light microscopy, gastrin immunoreactive cells during starvation markedly decreased in number and size. Quantitative electron microscopy revealed that during starvation the number of electron-lucent granules were greatly reduced, but the number of electron-dense granules increased; the number of intermediate granules were not remarkably changed in G cells. These results may suggest that the synthesis of gastrin and granule maturation were greatly inhibited during long-term starvation.
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PMID:Immunohistochemistry and morphometry of gastrin cells in the rat pyloric antrum during starvation. 379 93

The effects of cimetidine on plasma secretin were studied during prolonged fasting in order to determine whether gastric acid output influences secretin release under these circumstances. Twenty healthy volunteers starved for 36 h and were refed with oral glucose. They were given placebo or cimetidine (1.6 g daily) for 24 h before and during the starvation period. After 12 h fasting plasma secretin like immunoreactivity (SLI) was lower (P less than 0.02) in the cimetidine group than in the placebo group. After 36 h plasma SLI was higher (P less than 0.001) in both groups compared to the 12 h value but there was no statistically significant difference between the 2 groups. Refeeding caused prompt suppression of plasma SLI in both groups. Plasma gastrin was lower (P less than 0.001) after 36 h than 12 h in the placebo group only, but there was no significant difference between the groups. Blood glycerol (P less than 0.01) and 3 hydroxybutyrate (P less than 0.02) concentrations were higher after 36 h than after 12 h fasting in both groups. During fasting, sufficient to cause mobilisation of fat and ketosis, cimetidine failed to suppress plasma SLI. This may be due to inadequate suppression of gastric acid output or to some alternative stimulus to secretin release during fasting.
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PMID:Cimetidine fails to suppress the rise in plasma secretin during fasting. 399 16

Intracerebroventricular (icv) injection of pentagastrin showed a powerful, dose dependent antidipsogenic effect in the rat. Drinking behavior stimulated by 48 h water deprivation was inhibited by 2000 ng of pentagastrin which also blocked, at lower doses, water intake induced by icv injection of angiotensin II (100 ng) and carbachol (150 ng). Pentagastrin was less effective on food intake stimulated by 24 h starvation. The antidipsogenic effect was not a consequence of behavioral alteration. It is suggested that gastrin-like peptides in the brain may play a role in the regulation drinking, acting as thirst inhibitors.
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PMID:Effect of intracerebroventricular injection of pentagastrin on rat drinking behavior. 408 Jun 44

The influence of food deprivation on the release of somatostatin and gastrin from the rat stomach was investigated using an isolated, vascularly perfused rat stomach preparation. Basal and acetylcholine-stimulated gastrin release were significantly lower after a 3 day starvation, whereas the inhibitory effect of acetylcholine and the stimulatory effect of glucagon on somatostatin secretion were not influenced by fasting. In dose-response studies, isoproterenol dose-dependently stimulated somatostatin secretion. The increases were similar in both groups fasted for 12 and 72 h. Gastrin release remained at basal levels. Bombesin dose-dependently increased gastrin secretion; this stimulatory effect on the G cell was significantly reduced after a 72-h starvation. Somatostatin secretion was only weakly stimulated by high concentration of bombesin revealing no effect of fasting. Somatostatin content of the nonperfused stomach declined from 57 +/- 4 pmol/stomach in fed controls to 36 +/- 3 pmol/stomach after a 72-h fast. Antral gastrin concentration decreased by 42% in a 3-day fasting period. It is concluded that rat gastric somatostatin release in vitro is--in contrast to gastrin--not altered by food deprivation while the somatostatin content in gastric tissue declined during fasting.
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PMID:Effect of food deprivation on rat gastric somatostatin and gastrin release. 612 Aug 79

The effects of starvation and refeeding on intestinal cell proliferation at several sites of the rat gastrointestinal tract were studied and used as a model of altered cell proliferation in order to investigate the relationship between the rate of cell production and plasma gastrin and enteroglucagon. There was a marked fall in crypt cell production rate after four days starvation, with the proximal sites of the gut being most affected. The response to refeeding varied with site, suggesting that there was more than one mechanism for the control of intestinal cell proliferation. Plasma gastrin and enteroglucagon both fell to one fifth of their control level after starvation. Plasma gastrin increased slowly after refeeding, whilst plasma enteroglucagon increased rapidly to values significantly above control. Plasma gastrin was only correlated with crypt cell production in the duodenum, while plasma enteroglucagon was correlated with crypt cell production rate at several sites, indicating that enteroglucagon may be involved in the control of intestinal cell production.
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PMID:Cell proliferation, plasma enteroglucagon and plasma gastrin levels in starved and refed rats. 613 20

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

Various tumor cells contain chromatographically distinct isoacceptor tRNA species. To decide whether the tumor-specific species represent an expression of a separate tRNA gene or only an undermodified form of normal tRNAPhe, nucleotide sequences of tRNAPhe isolated from neuroblastoma and normal mouse liver were determined by postlabeling techniques. The results showed identical sequences except for the changes of post-transcriptional modifications in the anticodon loop. Normal mouse liver tRNAPhe contained Cm32, Gm34, and the hypermodified YOH next to the 3' end of the anticodon. On the contrary, tRNAPhe from neuroblastoma contained C32, G34, and, instead of YOH base m1G. A small proportion of tRNAPhe species contained an undermodified YOH base. For the examination of the conditions leading to the undermodified tRNAPhe, Vero cells derived from the kidney of African green monkey in culture were used. In these cells, deprivation of methionine or lysine resulted in changes in tRNAPhe modification similar to those in tumor cells. Ehrlich ascites tumor cells were examined to determine whether the presence of altered tRNAPhe species in various tumors is also the result of starvation of some nutritional factors. Results obtained with these cells showed that tRNAPhe species lacking the Y base disappeared in tumor-bearing mice after intraperitoneal injection with a mixture of amino acids and vitamins. Thus it is concluded that tumor-specific tRNAPhe species are the products of aberrant post-transcriptional modification, not the transcripts of different, normally repressed genes.
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PMID:Alterations in post-transcriptional modification of the Y base in phenylalanine tRNA from tumor cells. 640 57

The effect of a prolonged 5-day fast on the blood concentrations of vasoactive intestinal polypeptide (VIP), secretin, human pancreatic polypeptide (hPP), gastrin, and group I pepsinogens (PG I) was studied in 11 healthy subjects. During the fast there was a marked increase in the concentrations of VIP, secretin, and hPP, whereas the rise in the concentrations of gastrin and PG I was less pronounced. Refeeding suppressed the increased concentration of VIP and caused elevated postprandial concentrations of secretin and hPP, whereas starvation did not influence the postprandial release of gastrin and PG I. The study shows that prolonged starvation has a pronounced effect on gut endocrine responses.
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PMID:The fasting levels and the postprandial response of gastroenteropancreatic hormones before and after prolonged fasting. 666 32


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