Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “STARVATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63Linked to original sources
PubMed1981

Metabolic response to starvation. II. Effects of sex steroid administration to pre- and postmenopausal women.

Premenopausal women become more ketotic than do men during short term starvation. The possible influence of female sex steroids on ketosis during an 84-hr fast was studied in premenopausal women receiving combined oral contraceptive steroids. The results were compared to age and weight-matched women on no steroid birth control regimen. Although concentrations of several plasma substrates, insulin, and glucagon were measured throughout the fast, no differences between groups were observed with the exception of the 36-hr interval. At this time total plasma ketones and betahydroxybutyrate were significantly higher in women receiving oral contraceptives. In a second study six postmenopausal women were investigated in a similar fashion during a 36-hr fast. The procedure was repeated following a 5 day treatment regimen of oral estradiol and medroxyprogesterone acetate. After sex steroid treatment, total plasma ketones and betahydroxybutyrate concentrations exceeded control values significantly at 36 hr while plasma alanine and free fatty acid levels were significantly lower. The results suggest that oral estrogen-progestin combinations increase the ketogenic response of pre- and postmenopausal women during the early phases of total starvation. This hormonal effect may explain, in part, why women are more sensitive to fasting than are men.

Adult↗
PubMed1983

Insulin action during acute starvation: evidence for selective insulin resistance in normal man.

The effects of insulin on glucose utilization, lipolysis, and potassium and phosphate metabolism were studied during short-term fasting in six lean subjects using a sequential euglycemic glucose clamp technique (two additional subjects were used in 70 mU/m2/min clamp studies). The subjects were infused with insulin for four hours at four rates ranging from 6 to 442 mU/m2/min before and after a 48-hour fast. Insulin was infused for one hour at each rate in all experiments. Fasting markedly reduced glucose utilization at all insulin infusion rates. On the other hand, the decline in levels of free fatty acids that occurred at insulin concentrations of 30 microU/ml was virtually identical before and after fasting. After insulin was infused for four hours, serum phosphate had decreased in all subjects (P less than 0.001) and strongly correlated with glucose disposal rates (r = 0.76, P less than 0.005). The plasma potassium level also declined in all subjects but did not relate to fasting or glucose disposal. These studies demonstrate that starvation produces selective insulin resistance. The biologic effect of insulin on glucose utilization and plasma phosphate shifts is clearly diminished. Free fatty acid and potassium metabolism are unaffected by starvation.

Adult↗
PubMed1985

Starvation enhances the ability of insulin to inhibit its own secretion.

To examine whether decreased insulin secretion during starvation is related to a change in the ability of insulin to inhibit its own secretion, plasma C-peptide was measured after plasma insulin levels were acutely raised by intravenous (IV) insulin infusion in a dose of 40 and 80 mU/M2/min in obese subjects before and after a 72 hour fast. Plasma glucose concentration was maintained +/- 4% of basal levels by a variable glucose infusion. During the 80 mU infusion, at plasma insulin levels of 200 microU/mL, plasma C-peptide fell by 0.17 pmol/mL in the fed state. In the fasted state, despite basal levels that were 36% lower, C-peptide decreased by 0.21 pmol/mL. Highly significant increases in percent suppression after fasting were noted during both 40 mU and 80 mU studies. The plasma C-peptide response was related to the insulin infusion dose in both the fed and fasted state. In contrast, alpha cell suppression by insulin, as determined by plasma glucagon levels, was not altered by fasting. It is concluded that enhanced inhibitory influences of insulin on the beta cell during starvation may be a physiologically important mechanism for diminished insulin secretion during the transition from the fed to the fasting state.

Adult↗
PubMed1990

Protein synthesis in skeletal muscle during starvation and refeeding: comparison of data from intact muscle and muscle biopsy material.

The intact extensor digitorum longus (EDL) preparation in rat is a well-documented model for assessing protein synthesis in skeletal muscle. Human muscle biopsy material has also been used, but the extent to which biopsy material is representative for evaluation of muscle protein synthesis has not been established. Therefore, the aim of this study was to compare protein synthesis in intact muscle and in muscle biopsy material simultaneously in rats. The animals (70 g) were divided into three groups: fed (n = 22), starved for 36 hours (n = 22), and refed for 24 hours (n = 19). Protein synthesis and RNA content were measured in each group. Protein synthesis was determined as the incorporation of 14-C-phenylalanine into muscle protein in the intact EDL muscle from one leg and in a muscle biopsy from the contralateral EDL muscle. The incorporation of 14-C-phenylalanine was linear over time in both preparations, but was consistently lower in the muscle biopsy compared with the intact muscle. The relative change in incorporation, in % of that obtained in the fed state, showed a decrease in incorporation after 36 hours of starvation, in both intact muscle and in muscle biopsy material, 33% +/- 10% and 42% +/- 6%, respectively. After 24 hours of refeeding, an overshoot in protein synthesis was seen, to 136% +/- 6% in the intact muscle and to 133% +/- 6% in the muscle biopsy, as compared with the fed state. The RNA content decreased during the starvation period from 21.6 +/- 0.7 to 14.5 +/- 0.4 mg RNA/g protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Influence of repeated deprivation upon starvation-induced hypovolemia and plasma aldosterone concentration in rats.

Rats exposed to repeated periods of food deprivation during development revealed significant inhibition of starvation-induced hypovolemia as adults. Same age littermates food deprived once as adults indicated severe hypovolemia. Plasma aldosterone (but not angiotensin II) was significantly elevated in the repeatedly fasted group as compared with the control and the singly deprived groups. It is concluded that the repeated application of food deprivation during development results in physiological compensation in the form of increased aldosterone release if starvation is encountered in adulthood. These increments in plasma aldosterone promote greater sodium retention thus lessening the compromising of blood volume necessary to maintain normal plasma osmolality given the lack of dietary sodium.

Aldosterone↗
PubMed1980

Recovery of body weight following starvation or food restriction in rats.

Recovery of body weight and food intake have been studied and compared after a 25% weight loss produced by total starvation in one group of rats or by food restriction in a second group. It was shown that rats in both groups returned to their initial body weight within the same time on the average, but the hyperphagia observed during the recovery phase was significantly higher in restricted than in starved rats. In the former, the increase of food intake fully accounted for the weight gain. On the contrary, the recovery of body weight in previously starved rats involved both hyperphagia and a long lasting persistence of the fasting hypometabolism. In addition, it was shown that in those rats the higher the contribution of hypometabolism the longer the recovery. Starvation diabetes was higher in starved than in restricted rats and might be one factor which impairs weight regulation through hyperphagia after a weight loss induced by food deprivation.

Animals↗
PubMed1985

Metabolic and endocrine indices of starvation in bulimia: a comparison with anorexia nervosa.

Fifteen patients with bulimia (DSM-III) and 22 patients with anorexia nervosa (10 "restricters" and 12 "vomiters") were compared with 24 age- and sex-matched healthy controls. Serial blood samples were collected between 8:30 and 9:30 a.m. with patients in supine and standing positions. Elevated blood values of beta-hydroxybutyric acid and free fatty acids were observed in the majority of patients with bulimia and anorexia nervosa. These data indicate that many patients with bulimia showed the metabolic signs of starvation at the time of the study, a finding supported by the symptoms of endocrine adaptation to starvation, namely low triiodothyronine and a decreased noradrenaline response to an orthostatic test in many of these patients.

3-Hydroxybutyric Acid↗
PubMedDate not supplied

Effect of cold stress and starvation on the cerebral glucose-6-phosphate dehydrogenase activity of male garden lizards of three different age groups.

In the present study we observed that the cerebral glucose-6-phosphate dehydrogenase activity of male garden lizards did not change appreciably during maturation but showed a significant rise between middle-aged and old-aged groups. Whereas cold stress (1 h at 0-4 degrees C) induced a significant increase in G6PDH activity of young animals, it caused a decrease in both middle-aged and old lizards. This decrease was more severe in the old group than in the middle-aged group. Another form of stress, 72 hours of starvation, led to a significant increase in enzyme activity in young and in middle-aged lizards with young animals showing the greater effect. The old counter-parts showed a decrease in enzyme activity after starvation stress.

Aging↗
PubMed1979

Response of heterogenous rat liver lysosome populations to starvation and refeeding.

Starvation-induced alterations in liver lysosomes and their recovery pattern following refeeding were investigated. Fasting of adult rats for five days caused an increase in 'free' activities of acid hydrolyses in liver homogenates and loss in sedimentation of one of the heterogenous populations of lysosomes that could be isolated by differential centrifugation. Isopycnic sucrose gradient centrifugation revealed a decrease in the median and modal equilibration densities of all the forms of lysosomes in response to the dietary deprivation. Further, starvation also evoked a distinct bimodal distribution in a population that was rich in acid phosphatases, beta-galactosidase and N-acetyl-beta-glucosaminidase. Realimentation of starved animals for 10 days was found to restore the enzyme levels and the sedimentation characteristics to normal profiles.

Acetylglucosaminidase↗
PubMed1986

Effects of surgical stress on the response of hepatic carnitine metabolism to 48 h starvation in the rat.

Rats subjected to laparotomy and handling of the liver were starved for 48 h, starting either immediately after surgery or 48 h later. Surgery enhanced the rise in plasma non-esterified fatty acid concentrations after starvation without affecting the responses of blood or liver ketone bodies. Thus in surgically stressed rats, blood and liver ketone body concentrations were inappropriately low for the blood fatty acid concentrations. In the control rats, starvation increased hepatic carnitine concentrations, mainly through increases in short-chain acylcarnitine. Surgical stress decreased or abolished these increases. This may possibly contribute to the blunted ketonaemic response observed after surgery.

Anesthesia, General↗
PubMed1993

Metabolic fate of alanine in an insect Manduca sexta: effects of starvation and parasitism.

The fate of [3-13C]alanine administered to last instar larvae of an insect Manduca sexta was investigated in vivo by 13C-NMR spectroscopy. Following injection of the isotopically substituted substrate and conversion to [3-13C]pyruvate 13C was principally incorporated into C2, C3 and C4 of glutamate and glutamine in unparasitized ad libitum-fed larvae, insects starved 48 hr prior to injection and larvae parasitized by the insect parasite Cotesia congregata. Selective labeling at C2 and C3 of glutamate/glutamine resulted from carboxylation of [3-13C]pyruvate to [2,3-13C]oxaloacetate catalyzed by pyruvate carboxylase, randomization of the label in fumarate, and synthesis of glutamate and glutamine after condensation with acetyl CoA to [2 proR,3-13C]citrate. In contrast, enrichment at C4 of glutamate and glutamine resulted from oxidation [3-13C]pyruvate to [2-13C]acetyl CoA catalyzed by pyruvate dehydrogenase followed by condensation with oxaloacetate. The ratio of enrichment (C2 + C3): C4 provided a measure of the relative contributions of the pyruvate dehydrogenase and pyruvate carboxylase catalyzed pathways of substrate utilization by the tricarboxylic acid cycle. The mean ratio was 0.6 and 0.7 in control and parasitized larvae, respectively, and 2.4 in starved insects. The latter result demonstrated that substrate utilization by the TCA cycle was markedly altered by starvation. In addition, the rate of labeled alanine metabolism was significantly reduced by starvation. The concentrations of glutamate and glutamine in the blood (hemolymph) were similar in all three groups of insects. No evidence for gluconeogenesis was observed in any group. Starved larvae incorporated label into C6 of glucose and trehalose but no complementary enrichment at C1 was observed. This result was consistent with the activity of the non-oxidative phase of the pentose phosphate pathway during which labeled glyceraldehyde-3-phosphate arising from [3-13C]alanine reacts with sedoheptulose-7-phosphate yielding erythrose-4-phosphate and [6-13C]fructose-6-phosphate catalyzed by transaldolase. Specifically labeled fructose-6-phosphate then gives rise to glucose and trehalose labeled at C6. Preliminary analysis of the hemolymph of starved insects indicated the presence of several hexose phosphates labeled at C6. The hemolymph level of trehalose was significantly reduced in both starved and parasitized insects. Lipogenesis from [3-13C]alanine was evident in unparasitized control larvae but was absent in parasitized and starved insects. The pattern of labeling in fatty acid was consistent with de novo pathway utilizing [2-13C]acetyl CoA derived by oxidation of [3-13C]alanine.

Alanine↗
PubMed1977

The effects of starvation on the sodium, potassium, water and free amino acid content of parietal muscle from Agonus cataphractus.

1. The levels of the individual free amino acids, K, Na and water present in parietal muscle were measured in fish starved for periods of 3-115 days. 2. The Na and water content progressively increased relative to dry weight of tissue during the starvation period whereas an initial increase in the K content up to 67 days was followed by a decrease to near the normal fed level by 115 days. The ammonia content remained essentially stable over the same period. 3. The essential free amino acid content tended to follow the muscle sodium pattern while the non-essential amino acids and taurine gave results somewhat similar to those of potassium. 4. The net result of these changes is that the Na, K and total free amino acid concentration is maintained within fairly narrow limits relative to the tissue water content during 11-67 days of the starvation period under the experimental conditions used.

Amino Acids↗
PubMed1979

Effects of acute starvation on carbohydrate metabolism in rat salivary glands.

1. Effects of acute starvation on enzymes of carbohydrate metabolism were determined in rat submandibular and parotid glands. 2. Activities of glycolytic enzymes were high in submandibular gland, but those of pentose phosphate pathway and glycogen metabolism were high in parotid gland. 3. Enzyme activities were lowered by acute starvation. Refeeding the rats with solid diet restored the enzyme activities, but with liquid diet, only partial recoveries were found in submandibular gland.

Animals↗
PubMed1984

Properties of the lysosomes from liver and gill of rainbow trout, Salmo gairdnerii R.: effect of starvation, salinity and 2,4,5-T.

Three isolation procedures were used to test the labilization of the lysosomes after adaptation of the animals to seawater, starvation or acute and chronic treatments with 2,4,5-T, an organochlorine pesticide. The lysosomes from gill and liver had different properties with respect to their resistance to osmotic and mechanical shocks, or treatments with digitonin. Starvation induced a significant labilization of the lysosomes in liver, but not in gill. Salinity changes were without effect on the stability of the gill lysosomes, but induced an increase of the specific activity of the lysosomal enzyme beta-acetylglucosaminidase. Acute treatments with 2,4,5-T increased lysosomal fragility in the gill but not in the liver, while chronic treatments with this herbicide increased lysosomal lability in the two tissues. Liver lysosomes were much more susceptible to in vitro treatments with 2,4,5-T than gill lysosomes. The results are discussed with respect to the different functions of gill and liver, their exposure to the environment, and the possible discrimination between different lysosomal populations.

2,4,5-Trichlorophenoxyacetic Acid↗
PubMed1988

Gluconeogenesis in perfused chicken kidney. Effects of feeding and starvation.

1. Starvation for 48 hr doubled the rate of gluconeogenesis from lactate and pyruvate in perfused chicken kidney, but did not change the rate of production of glucose from malate, succinate, or alpha-ketoglutarate. 2. Amino-oxyacetate and D-malate inhibited the production of glucose from lactate and from pyruvate by 55% in each case. Quinolinate reduced the production of glucose from lactate and from pyruvate by 50% in both fed and starved chickens, but had no effect on the production of glucose from intermediates in the citric acid cycle. 3. Starvation increased the rate of formation of mitochondrial phosphoenolpyruvate from pyruvate, but had no effect on the rate of formation of mitochondrial phosphoenolpyruvate from malate.

Animals↗
PubMed1990

Comparative studies on lipogenic enzyme activities in brown adipose tissue and liver of the rat during starvation-refeeding transition and cold exposure.

1. The effect of starvation-refeeding transition and cold exposure on the activity of lipogenic enzymes in brown adipose tissue (BAT) and liver from rats was compared. 2. Starvation caused a decrease of lipogenic enzyme activities in BAT and liver. 3. Refeeding of the animals with a high carbohydrate diet caused an increase of lipogenic enzymes in these tissues. 4. Cold exposure (4 degrees C for 30 days) led to the increase of BAT enzyme activities to the values observed in rats fed a high carbohydrate diet. 5. Under the same conditions the activity of hepatic lipogenic enzymes also increased but never reached the values observed in the liver of rats fed with a high carbohydrate diet. 6. Therefore BAT and liver lipogenic enzymes showed, in general, a similar pattern of variation under identical nutritional conditions, but substantial differences between these two organs occurred as far as the response to cold exposure was concerned. 7. The experiments also revealed that in the control animals BAT displayed a higher lipogenic potential than the liver.

Adipose Tissue, Brown↗
PubMedDate not supplied

Starvation diet and very-low-calorie diets may induce insulin resistance and overt diabetes mellitus.

We have observed seven initially obese individuals who, during the course of a strenuous weight-reduction program, developed diabetes mellitus: non-insulin-dependent diabetes mellitus in five cases and insulin-dependent diabetes mellitus in two cases. None had any sign of prior diabetic symptoms. Although weight reduction is encouraged in obesity, crash diets without proper medical surveillance may have deleterious effects. This sequence of induction of diabetes has not previously been reported in the medical literature. The metabolic situation in extremely low-calorie diets may be comparable to that in starvation. An attempt is made to explain our observation concerning the induction of a diabetic state during such diets, on the basis of increased insulin resistance in states of starvation and anorexia nervosa, with a concomitant role in stress hormones.

Adult↗
PubMed1995

Effect of prolonged starvation on the activities of malic enzyme and acetylcholinesterase in tissues of Japanese quail.

During starvation muscle protein degradation is increased but the mechanism for this is uncertain. In this study Japanese quail were starved for 5 days and the activities of malic enzyme and acetylcholinesterase were determined in various tissues. SDS-polyacrylamide gel electrophoresis showed that the soluble proteins with molecular weights corresponding to 160, 120, 108, 99 and 38 kDa were absent in the liver of the starved group. In the pectoral muscle the soluble proteins with molecular weights corresponding to 69, 41 and 34 kDa were missing. The activity of malic enzyme in the liver, heart and pectoral muscle of the starved group decreased markedly whereas that of acetylcholinesterase increased markedly in the pectoral muscle (P < 0.005). It is concluded that in prolonged starvation acetylcholinesterase synthesis may be induced in tissues being subjected to protein catabolism and that this enzyme may be involved as a protease in protein degradation.

Acetylcholinesterase↗