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

Using histochemical techniques the glycogen content and the activities of glycogen synthetase (UDPGGT) and phosphorylase were studied in the livers of 106 golden hamsters under following experimental conditions; a) starvation of 16, 36, 48, 72, and 96 hours: b) alloxan-diabetes. Starvation leads to a depletion of liver glycogen during the first 48 hours, which is finally restricted to zone 3 of the liver acinus. After starvation of 72 and 96 hours a new glycogen accumulation is demonstrable in the microvasculatory periphery of the acinus (zone 3 and 2). The process of glycogen depletion is characterized in the beginning by a high phosphorylase activity in all zones of the acinus, later only in the forefield of glycogen content. The weak activity of glycogen synthetase is mainly restricted to zone 3. All phases of glycogen depletion are to be found in alloxan diabetic animals, too. Out of 45 hamsters 23 showed an extreme depletion of glycogen; typical for this situation is a weak or absent glycogen synthetase activity in zone 3 and a broad field of phosphorylase activity in zones 1 and 2. The short stimulation by insulin leads to a considerable increase of glycogen synthetase activity at the portally oriented border of the glycogen area and to a shift of the moderate phosphorylase activity of zone 1. Thus the histochemical characteristics of glycogen depletion are: a shift of the reduced glycogen content in direction of the microvasculatory periphery of the liver acinus (zone 3), caused by a high phosphorylase activity in the portal forefield, while glycogen synthetase activity is low in the glycogen area. The histochemical characteristics of glycogen accumulation are: after a short phase of glycogen synthesis in all hepatocytes a moderate phosphorylase activity in zone 1 leads to a mobilization of the portal glycogen deposits and to an increasing accumulation of glycogen in the peripheral part of the acinus. At the portally oriented border of the glycogen area a high synthetase activity leads to a broadening of the glycogen area in direction of the portal branches. At the end of this process the "normal" pattern of the liver acinus occurs: all hepatocytes are filled with glycogen, the glycogen enzymes are restricted to the periportal border of zone 1.
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PMID:Dynamics of liver glycogen: the topochemistry of glycogen synthesis, glycogen content and glycogenolysis under the experimental conditions of glycogen accumulation and depletion. 81 13

Twenty-three postoperative patients were divided into three groups to evaluate the peripheral vein administration of solutions containing glucose, amino acids, or glucose and amino acids. Serum insulin, glucose, and nitrogen balances were monitored in each patient. Serum insulin concentrations rose on the first postoperative day in all three groups, then fell to near preoperative levels by the third day after surgery. Negative nitrogen balance was most pronounced in patients recieving glucose only. Patients receiving only amino acids had a reduction in nitrogen balance, but some protein catabolism was present. The mean nitrogen balance in patients who received a combination of these solutions was positive on days one and two after surgery and slightly negative on the third postoperative day. These changes were not significantly better than the amino acid group. However, the combination group had 12 to 21 days of positive balance, as compared to seven of 20 days in the amino acid group. Since starvation adaptation accurs gradually, it is concluded that the simplest and safest way to reduce protein catabolism in the immediate postoperative period is by the peripheral intravenous administration of both glucose and amino acids.
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PMID:Endogenous caloric sources and nitrogen balance: regulation in postoperative patients. 82 36

Studies in man and experimental animals suggest that the metabolism of glucose by skeletal muscle is depressed during starvation. To investigate the basis for this, the effect of starvation on the uptake and disposition of glucose in skeletal muscle was studied in the isolated perfused rat hindquarter. In contrast to earlier work carried out in heart, neither glucose uptake, whether stimulated by insulin or exercise, nor glycolysis were depressed by 48 hr of starvation or by perfusion of the hindquarter with acetoacetate, palmitate, or octanoate. Glucose oxidation, assessed from the oxidation of 1-[14C]lactate, was depressed by approximately 75% in starved rats and by 30% in fed rats perfused with acetoacetate. Exercise increased lactate oxidation 10-fold in both fed and starved rats; however, the relative difference between the groups persisted. In general, changes in lactate oxidation were paralleled by changes in the activity of pyruvate dehycrogenase (active form). The data suggest that glucose metabolism in skeletal muscle is inhibited during starvation at the step of pyruvate oxidation and that this inhibition persists during exercise. The also suggest that the diminution of glucose uptake that occurs in skeletal muscle of intact organisms during starvation may not be related to the presence of high concentrations of free fatty acids and ketone bodies.
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PMID:Effect of starvation on muscle glucose metabolism: studies with the isolated perfused rat hindquarter. 83 85

The influence of low carbohydrate (CHO) diets, starvation, and high CHO diets on glucose tolerance tests (GTT) and plasma insulin response of men with chemical diabetes was studied. The GTT and insulin responses of these seven lean diabetic men were unchanged when the carbohydrate content of the diet was reduced from 44 to 20% of calories. After a 48-hr fast a significant deterioration of the GTT was observed in these diabetic men but the percentage change was identical to that reported previously for normal men. Thus these studies indicate that changes in glucose mtes are quite similar to those reported previously for normal men. The fasting plasma glucose values of seven lean and four obese men with chemical diabetes were significantly lower after one week on a 75% CHO diet than values on a 44% CHO diet. The 75% CHO diet also was accompanied by slight improvements in the oral and intravenous GTT and by slightly lower plasma insulin responses. The improvement in glucose metabolism on high CHO diets appears to results from increased insulin sensitivity. Serum triglyceride values were approximately 55% higher on the 75% CHO diet than values on the 44% CHO diet for the 11 men but these differences were not statistically significant. These studies support previous observations and suggest that high CHO diets may be beneficial in the management of certain diabetic patients. However, further studies are required to determine the long-term effects of high CHO diets containing natural foods on the glucose and lipid metabolism of diabetic patients.
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PMID:Effect of carbohydrate restriction and high carbohydrates diets on men with chemical diabetes. 84 91

1. Rates and rate coefficients of glucose utilization and replacement in post-absorptive rats, either conscious or under halothane anaesthesia, were determined in a thermoneutral environment by using [5-3H]- and [U-14C]glucose. Label was not injected into rats under halothane until about 0.5h after anaesthesia was initiated. 2. Comparison with the results for 24h-starved rats in the preceding paper [Heath et al. (1977) Biochem. J. 162, 643-651] showed that insulin concentrations were considerably higher but rate coefficients for glucose utilization were little altered in post-absorptive rats. Sensitivity to insulin was thus considerably increased by a 24h period of starvation in the rat. 3. Fractional recycling of glucose carbon in post-absorptive rats was under one-half of that in starved rats, reflecting the larger contribution of liver glycogenolysis to glucose production in the former. 4. In post-absorptive rats halothane decreased the mean rate of glucose utilization by about 17%. This decrease was associated with an increase in mean plasma insulin concentration, showing that halothane decreased sensitivity to insulin. 5. Recycling was slightly increased by halothane, indicating that the contribution of liver glycogen to the total glucogenic rate was decreased, probably because liver glycogen concentration were about 40% lower throughout the rate determinations in halothane. 6. Comparison of our results with earlier work shows that during and shortly after induction of halothane anaesthesia glucose turnover must have been greatly increased whereas from about 0.5h after induction it was decreased.
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PMID:Glucose turnover in the post-absorptive rat and the effects of halothane anaesthesia. 86 9

During a 72-hr period of starvation plasma levels of glucose and immunoreactive insulin fell to a greater extent, and alanine, free fatty acid, and glycerol concentrations were higher in fasted chronically uremic rats than in nonuremic controls. These changes, in conjunction with a significant increase in the uremic group's activity of phosphoenolypyruvate-carboxykinase, the rate-limiting enzyme in hepatic gluconeogenesis, after only 12 hr of fasting suggest that alterations in glucose metabolism in uremia may contribute to an exaggeration and acceleration of the metabolic consequences of starvation.
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PMID:Evidence for an accelerated adaptation to starvation in chronic uremia. 89 25

Oral glucose tolerance tests were performed on 14 lean and 14 obese nondiabetic subjects before and after a 6-day fast. In addition, insulin tolerance tests were performed on 8 lean and 8 obese subjects before and after starvation. Both in lean and obese subjects glucose tolerance deteriorated during starvation, but much more so in the lean population. During fasting, insulin elevation after a glucose load was significantly delayed in lean subjects but not in the obese. Circulating levels of factors known to affect glucose tolerance, such as glucagon, growth hormone, free fatty acids, and ketone bodies were higher in fasting lean than in fasting obese individuals. In normals fasting resulted in a significant decrease of the blood glucose response to insulin injection, whereas in fasting obese subjects glucose response was unchanged. The results obtained suggest that the effect of fasting on insulin release and insulin sensitivity was more pronounced in lean than in obese subjects, which resulted in greater deterioration of glucose tolerance in the lean population.
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PMID:Mechanism of glucose intolerance during fasting: differences between lean and obese subjects. 89 29

Glucose and fructose were studied in eight healthy volunteers who fasted twice for 4 days. Before and after the fasts each subject received a 4-hr glucose or fructose infusion providing 0.5 g/kg/hr. Glucose infusion during starvation resulted in a mean maximal plasma glucose rise of 401 +/- 21 mg/100 ml (+/- SEM) as compared to 119 +/- 10 mg/100 ml before starvation. Insulin/glucose ratios were lower than normal in fasted subjects. Fructose infusion during fasting produced a maximal plasma glucose rise of 91 +/- 9 mg/100 ml as opposed to 5+/-1 mg/100 ml before starvation. During fructose infusion in the fasted state, plasma fructose levels were higher than control and the rise in blood lactate and pyruvate was delayed, but finally lactate concentrations were above control values. The antiketotic effects of intravenous glucose and fructose were similar during fasting but fructose was significantly less potent in reducing free fatty acid levels. After starvation, urinary carbohydrate losses during glucose infusion were 5 times higher than those observed during fructose infusion. Thus, fructose utillization was less impaired during fasting than was glucose utilization, although fasting induced abnormalities in both glucose and fructose metabolism.
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PMID:Comparison of glucose and fructose tolerance before and after starvation. 90 56

The high blood cholesterol and glucagon levels of suckling rats can be rapidly decreased within 24 hours by prematurely weaning rats to a high carbohydrate diet on day 18. The fall in the cholesterol level is much smaller if rats are starved for 24 hours. This decrease can partly be inhibited by injections of glucagon. The only factor so far found to decrease blood cholesterol levels in suckling rats was starvation. Insulin, which slightly but significantly, depressed the level in 40 day old rats, increased it in suckling ones, as does prednisolone. It is concluded that blood cholesterol levels are more easily manipulated in suckling rats than in older rats, and that this is probably related to a different hormonal balance.
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PMID:Control of blood cholesterol levels in suckling and weanling rats. 90 64

Glucagon binding by liver cell membranes was examined in rats with chronically elevated plasma levels of immunoreactive glucagon (IRG) resulting from insulin deficiency, starvation, or twice daily glucagon injections. The concentration of specific glucagon binding sites was significantly reduced in the three chronically hyperglucagonemic (IRG greater than 125 pg/ml) groups as compared with nondiabetic controls and insulin-treated diabetic control rats with only mild hyperglucagonemia. A reduction in glucagon binding sites did not occur with hyperglucagonemia of 12 h or less. Despite the reduced binding of glucagon in the three chronically hyperglucagonemic groups, the ability of glucagon to stimulate cAMP production was not reduced. It is concluded that while decreased glucagon binding occures in the forms of chronic hyperglucagonemia studied, it is not associated with a reduction in the ability of glucagon to stimulate cAMP production.
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PMID:Binding and biologic activity of glucagon in liver cell membranes of chronically hyperglucagonemic rats. 91 19


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