Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this preliminary study, 120 cord blood samples were subjected to a simple on-the-ward triglyceride screening procedure and 15 were designated as being high and another 15 randomly selected as controls. All the samples were then subjected to detailed biochemical analysis for fatty acid profiles and/or concentrations of free fatty acids, triglycerides (TG), phospholipids, cholesterol esters and glycerol. Eleven of the samples designated 'high' were associated with one or more of the following clinical conditions: family history of ischaemic heart disease, maternal starvation, fetal distress, light-for-dates babies and excessive weight gain during pregnancy. There was an association between high TG levels and high glycerol levels. The fatty acid pattern of the TG was altered when at abnormally high concentration, in particular oleic acid was increased relative to the others, and this was associated with an increase in cholesterol ester oleic acid. The possible mechanisms resulting in cord hypertriglyceridaemia are discussed.
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PMID:Cord blood hypertriglyceridaemia as an index of fetal stress: use of a simple screening test and results of further biochemical analysis. 63 98

The influence of exercise on forearm muscle metabolism was examined in 9 healthy subjects, in 16 diabetics and in 4 obese subjects during complete starvation. During exercise glucose uptake rose 7-8 fold in the controls. However, no increase of glucose uptake was observed in the other groups studied. Moreover, a glucose production from the working muscle took place in about 40 percent of both the diabetic patients and the starved obese subjects. The nonutilization of glucose during physical work in the diabetic like states was accompanied by a significantly diminished lactate output. The arterial concentration of FFA, glycerol beta-HOB and Acac was markedly elevated in the starved obese patients. The FFA-uptake at rest and during exercise, however, was not different from results of controls. Whereas an effux of beta-HOB has been observed during exercise, Acac uptake was increased in these patients. It is suggested that in maturity onset and starvation diabetes glycolysis is inhibited.
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PMID:Muscle metabolism during exercise in diabetics and in obese during starvation. 68 Jun 26

A glycerol-requiring mutant of Salmonella typhimurium was used in a study of the biosynthesis and assembly of a structural lipoprotein in the cell envelope of gram-negative bacteria. Upon removal of glycerol from the growth medium, the biosynthesis of lipoprotein, as measured by radioactive arginine incorporation, was reduced by the same extent as that of other envelope proteins, the cumulative incorporation of arginine being 20% of that of the unstarved control cells. However, the incorporation of radioactive palmitate into lipoprotein was more severely curtailed after glycerol starvation, the cumulative rate of which was 8% of that observed in the unstarved cells. It was further observed that the lipoprotein synthesized in the glycerol-starved cells was more enriched in unmodified cysteine, which is known to be the N-terminal amino acid of lipoprotein, than that synthesized in the unstarved cells. We conclude that the synthesis of the apoprotein portion of Braun's lipoprotein proceeds independently of the attachment of diglyceride to the sulfhydryl group of the N-terminal cysteine and may, in fact, precede the incorporation of the diglyceride moiety.
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PMID:Biosynthesis and assembly of envelope lipoprotein in a glycerol-requiring mutant of Salmonella typhimurium. 76 31

The metabolic function of triaclyglycerol in Tetrahymena pyriformis was investigated by prelabeling endogenous lipid with a 14C-labeled short chain fatty acid, and then following the disappearance of radioactivity from triacylglycerol and its appearance in other products. In 90 min, up to 85% of the label in triacylglycerol turns over, and although some radioactivity appears in CO2 and glycogen, most of the label appears in phospholipid. Starvation of the cells, as well as resuspension in enriched medium or provision of acetate all block triacylglycerol breakdown, while supplementation of the medium with pyruvate does not. Prelabeling lipid with [3H] glycerol shows that some of the transfer of material from triacylglycerol to phospholipid involves transfer of the glycerol backbone, although transfer of triacylglycerol fatty acids directly to phospholipid probably also occurs. In addition, the catabolism of triacylglycerol occurs by a "last-in-first-out" mechanism, indicating some form of compartmentation of triacylglycerol in this cell. The results demonstrate an important metabolic interrelationship between triacylglycerol catabolism and phospholipid synthesis and raise the question, in this cell at least, of the validity of considering triacylglycerol only as a fuel storage form.
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PMID:Triacylglycerol turnover in Tetrahymena pyriformis. Relation to phospholipid synthesis. 81 31

Phosphate starvation induced teichuronic acid synthesis in cells of Bacillus subtilis 168trp-which had previously been grown with excess phosphate. This induction was prevented when protein systhesis was inhibited immediately prior to phosphate starvation and under these conditions cells continued to form teichoic acid. The converse was true when phosphate was added to cells previously grown in a phosphate-limited chemostat. The increase in teichoic acid synthesis normally following phosphate addition was prevented by chloramphenicol or amino acid starvation and cells continued to make teichuronic acid. This suggestion that repression of enzyme synthesis is involved in controlling the type of wall polymer made was supported by the low levels of UDP-glucose dehydrogenase found in cells grown with excess phosphate and of CDP-glycerol pyrophosphorylase in phosphate-limited cells. The greater amounts of teichoic acid made under phosphate limitation and of teichuronic acid with excess phosphate when protein synthesis was also inhibited indicated that modulation of enzyme activity occurs. Glycerol starvation of a glycerol-requiring mutant did not derepress teichuronic acid synthesis, indicating that glycerol-containing imtermediates do not act as repressors.
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PMID:Control of teichoic and teichuronic acid biosynthesis in Bacillus subtilis 168trp. Evidence for repression of enzyme synthesis and inhibition of enzyme activity. 81 32

Acute starvation of the pregnant rabbit before delivery leads to lipid mobilization, the circulating concentrations of free fatty acids (FFA) increase, and more fatty acids cross the placenta and are stored as triglyceride in fetal tissues, particularly the liver and adipose tissue. Thus the newborns from these unfed does are born with larger fat stores than normal. In this investigation the responses of newborns of unfed and fed does were compared with respect to aspects of the metabolic responses to birth and subsequent cold exposure. It was found that at 2 hr of age the newborns of unfed does had higher circulating concentrations of FFA and triglycerides. The glucose and glycerol concentrations were similar in the two groups, but after 2 hr of cold exposure the newborns of fed does had much higher blood concentrations of both glucose and glycerol. In both, a large increase in FFA concentration was seen. The newborns of unfed and fed does had similar minimal metabolic rates, but the maximal rate of heat production was greater on average by 15% in the newborns of unfed does over the first 3 days of life. Maternal nutrition immediately before delivery has considerable effect on the circulating concentrations of metabolites and the responses to cold of the newborn.
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PMID:The effect of maternal starvation on the metabolic response to cold of the newborn rabbit. 87 97

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

Extracts of Acetobacter xylinum catalyze the phosphorylation of glycerol and dihydroxyacetone (DHA) by adenosine 5'-triphosphate (ATP) to form, respectively, L-alpha-glycerophosphate and DHA phosphate. The ability to promote phosphorylation of glycerol and DHA was higher in glycerol-grown cells than in glucose- or succinate-grown cells. The activity of glycerol kinase in extracts is compatible with the overall rate of glycerol oxidation in vivo. The glycerol-DHA kinase has been purified 210-fold from extracts, and its molecular weight was determined to be 50,000 by gel filtration. The glycerol kinase to DHA kinase activity ratio remained essentially constant at 1.6 at all stages of purification. The optimal pH for both reactions was 8.4 to 9.2. Reaction rates with the purified enzyme were hyperbolic functions of glycerol, DHA, and ATP. The Km for glycerol is 0.5 mM and that for DHA is 5 mM; both are independent of the ATP concentration. The Km for ATP in both kinase reactions is 0.5 mM and is independent of glycerol and DHA concentrations. Glycerol and DHA are competitive substrates with Ki values equal to their respective Km values as substrates. D-Glyceraldehyde and l-Glyceraldehyde were not phosphorylated and did not inhibit the enzyme. Among the nucleotide triphosphates tested, only ATP was active as the phosphoryl group donor. Fructose diphosphate (FDP) inhibited both kinase activities competitively with respect to ATP (Ki= 0.02 mM) and noncompetitively with respect to glycerol and DHA. Adenosine 5'-diphosphate (ADP) and adenosine 5'-monophosphate (AMP) inhibited both enzymic activities competitively with respect to ATP (Ki (ADP) = 0.4 mM; Ki (AMP) =0.25 mM). A. xylinum cells with a high FDP content did not grow on glycerol. Depletion of cellular FDP by starvation enabled rapid growth on glycerol. It is concluded that a single enzyme from A. xylinum is responsible for the phosphorylation of both glycerol and DHA. This as well as the sensitivity of the enzyme to inhibition by FDP and AMP suggest that it has a regulatory role in glycerol metabolism.
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PMID:Phosphorylation of glycerol and dihydroxyacetone in Acetobacter xylinum and its possible regulatory role. 95 17

The stimulatory effect of starvation on omega oxidation of stearate by the 20,000 X g supernatant fluid of rat liver homogenates was studied. The effect was obtained after starvation for 24 hours. Starvation for longer times did not further increase omega oxidation. The stimulatory effect of starvation on omega oxidation of stearic acid was accompanied by a reduced incorporation of stearic acid into phosphatidic acid, diglycerides, and triglycerides. Substitution of the 100,000 X g supernatant fluid from liver homogenate of starved rats with 100,000 X g supernatant fluid from liver homogenates of control rats reduced the microsomal omega oxidation of stearic acid with a simultaneous increase in incorporation of stearic acid into the different glycerides. Under the latter conditions almost no free stearic acid could be isolated from the incubation mixture after the incubation. Of three different soluble factors necessary for glyceride formation, ATP appeared to be the most important from a regulatory point of view. Thus the soluble fraction of liver homogenate from a starved rat was shown to contain suboptimal concentrations of ATP. Addition of physiological amounts of ATP to the 20,000 X g supernatant fluid of homogenate of liver of starved rats had the same effect as addition of 100, 000 X g supernatant fluid from liver homogenate of control rats, i.e. decrease in omega oxidation and increase in formation of glycerides. Addition of sn-glycerol 3-phosphate and CoA-SH in amounts optimal for glyceride formation to the 20,000 X g supernatant fluid of liver homogenate of starved rats had only small effects on omega oxidation and glyceride formation. The results are consistent with a competition for free fatty acids between the acyl-CoA synthetases involved in biosynthesis of glycerides and the microsomal hydroxylase(s) involved in omega oxidation of fatty acids. The concentration of ATP in the soluble fraction is of importance in this competition. The possibility is discussed that this competition is of importance also under in vivo conditions and that a decreased rate of esterification in the starved state is responsible for the higher excretion of omega-oxidized fatty acids in urine in the ketotic state.
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PMID:On the mechanism of regulation of omega oxidation of fatty acids. 95 85

Glycerol starvation of an Escherichia coli glycerol auxotroph results in a specific inhibition of membrane phospholipid synthesis. Mindich ((1972) J. Bacteriol. 110, 96-102) observed only a trace accumulation of free fatty acid following glycerol deprivation. We have repeated these experiments using glycerol auxotrophs which also possess a lesion in beta oxidation. This defect was introduced in order to control fatty acid degradation. In contrast to the previous results, we find free fatty acid does accumulate during glycerol starvation. Similar results were found using beta oxidation-defective (fadE-) derivatives of both gpsA and plsB glycerol auxotrophs. Upon glycerol starvation of a plsB- fadE- strain, phospholipid synthesis is 90 percent inhibited. Following a lag of 20 to 40 min, free fatty acid synthesis begins and proceeds at a rate that steadily increases until the rate of fatty acid synthesis is equal to that found in glycerol-supplemented cultures. The accumulation of free fatty acid is the result of de novo synthesis. The average chain length of the fatty acid in the unesterified fraction is abnormally long. Two 20-carbon fatty acids, cis-13-eicosenoic acid and arachidic acid, are found in this frction. Furthermore, a greatly increased level of stearic acid and a small amount of a C-22 (behenic) acid are found in the free fatty acid fraction. These data indicate that acyl transfer into phospholipid is a major determinant of phospholipid acyl moiety chain length. Other experiments have shown that the free fatty acid fraction in glycerol-starved cells is metabolically active. This fraction turns over despite the defective beta oxidation system. Restoration of glycerol to starved cells allows the incorporation of the unesterified fatty acids into phospholipid.
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PMID:Regulation of membrane lipid synthesis in Escherichia coli. Accumulation of free fatty acids of abnormal length during inhibition of phospholipid synthesis. 109 44


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