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

In bilaterally nephrectomized rats and in normal rats treated with 0.1 N HCl elevated levels of plasma total glycerol and lowered FFA and free glycerol are observed after a period of 25 h of starvation. In both cases the removal of intravenous lipid loads is slowed down, plasma LA is decreased after starvation and after lipid loads. The bicarbonate treatment of nephrectomized rats tends to normalize the plasma lipid levels and LA as well as the removal of intravenous lipid loads. The etiological importance of acidosis in uremic hypertriglyceridemia and possible clinical significance is pointed out.
 ...
PMID:Lipid metabolism in uremic and nonuremic acidosis. 4 Nov 94

1) Thyroidectomized rats were fed with a low iodine diet, injected daily with 0, 0.1, 1.8 or 25 microgram of L-thyroxine/100 g body wt., and compared with intact controls. 2) Plasma protein-bound iodine was decreased in the rats given the 0 and 0.1 microgram doses, unchanged in those given the 1.8 microgram doses, unchanged in those given the 1.8 microgram dose increased in those given the 25 microgram one. 3) The liver content of DNA-P, phospholipid-P, proteins and fatty acids was decreased in the rats that did not receive thyroxine, practically recuperated in those receiving 0.1 microgram and normal in those given 1.8 or 25 microgram of thyroxine. 4) 3 h of starvation produced a reduction in the liver content of total fatty acids that disappeared after 24 h. 5) When fed, liver glycogen concentration was low in the rats given 25 microgram of thyroxine. 6) With starvation, the fall in liver glycogen and blood glucose, and the rise in liver acetyl-CoA and citrate and blood glycerol concentrations were faster in the thyroidectomized rats that did not receive thyroxine than in the other groups. 7) The rise in plasma free fatty acid and blood ketone bodies concentrations were similar in all the groups, the greater level of the first parameter being observed after 6 h of starvation in the rats given 25 microgram of thyroxine and in the second one after 24 h in the rats given either 0.1, 1.8 or 25 microgram of thyroxine. 8) The rapid decrease in the availability of carbohydrate stores with starvation in the thyroidectomized rats could be responsible for their fast call for lipid utilization. The slower response to fasting in the hyperthyroid animals is probably a consequence of their reduced amount of endogenous substrates to be mobilized.
 ...
PMID:Metabolic response to short periods of starvation in hypo- and hyper-thyroid male rats. 7 35

Exponential biosynthesis and excretion of lipoteichoic acid (LTA) during the exponential phase of growth, and continued synthesis and excretion during valine starvation of Streptococcus faecium (S. faecalis ATCC 9790), were shown. During exponential growth, extracellular LTA (LTAx) accounted for approximately 13% of the total LTA in cultures, whereas during valine starvation, this percentage increased to approximately 60% within 4 h. LTAx was present in a low-molecular-weight, apparently deacylated form, whereas intracellular (LTAi) was present primarily in an apparently high-molecular-weight, acylated and micellar form. Experiments utilizing chases of either fully equilibrated or short pulses of [14C]- or [3H]glycerol were used to demonstrate that LTAx was derived directly from LTAi.
 ...
PMID:Precursor-product relationship of intracellular and extracellular lipoteichoic acids of Streptococcus faecium. 10 43

Two DNA polymerases were detected in Tetrahymena pyriformis, strain GL. One (enzyme I) was sensitive to N-ethylmaleimide, while the other (enzyme II) was insensitive. The molecular weight of the enzymes, as determined by glycerol gradient centrifugation analysis, were approximately 130,000 and 70,000, respectively. Optimal concentration of MgCl2 was 10mM for enzyme I and 18mM for enzyme II. KCl inhibited enzyme I but stimulated enzyme II. Poly (dA-dT) served effectively as a template for enzyme I, while poly(dA).(dT)12-18 was an effective template for enzyme II. Enzyme I activity increased with cell growth and sharply declined after the cells reached the stationary phase. On the other hand, enzyme II activity appeared only at the end of log phase. In cells synchronized by starvation-refeeding technique enzyme I was markedly stimulated in correspondence to the rate of DNA synthesis, whereas the level of enzyme II activity changed to lesser extent. By ethidium bromide treatment, only enzyme I activity was induced.
 ...
PMID:Presence of two DNA polymerases in Tetrahymena pyriformis. 11 38

Growth of Halobacterium halobium under illumination with limiting aeration induces bacteriorhodopsin formation and renders the cells capable of photophosphorylation. Cells depleted of endogenous reserves by a starvation treatment were used to investigate the means by which energy is coupled to the active transport of [14C]proline, -leucine, and -histidine. Proline was readily accumulated by irradiated cells under anaerobiosis even when the photophosphorylation was abolished by the adenosine triphosphatase inhibitor N,N'-dicyclohexylcarbodimiide (DCCD). The uptake of proline in the dark was limited except when the cells were allowed to accumulate adenosine 5'-triphosphate (ATP) by prior light exposure or by the oxidation of glycerol. DCCD inhibited this dark uptake. These findings essentially support Mitchell's chemiosmotic theory of active transport. The driving force is apparently the proton-motive force developed when protons are extruded from irradiated bacteriorhodopsin or by the dydrolysis of ATP by membrane adenosine triphosphatase. Carbonylcyanide m-chlorophenylhydrazone (CCCP), a proton permeant known to abolish membrane potential, was a strong inhibitor of proline uptake. Leucine transport was also apparently driven by proton-motive force, although its kinetic properties differed from the proline system. Histidine transport is apparently not a chemiosmotic system. Dark- or light-exposed cells show comparable initial rats of histidine uptake, and these processes were only partially inhibited by DCCD or CCCP. The histidine system apparently does not utilize ATP per se since comparable rates of uptake were exhibited by cells of differing intracellular ATP levels. Irradiated cells did effect a greater total accumulation of histidine than dark-exposed cells. These findings suggest that ATP is needed for sustained transport.
 ...
PMID:Energy coupling in the active transport of amino acids by bacteriohodopsin-containing cells of Halobacterium holobium. 12 52

In conditions of glucose starvation, the maximum velocity of the mediated transport of nonmetabolized and metabolized amino acids, uridine, adenosine, and sucrose across the plasma membrane is stimulated by a factor of two by the addition of 1 mM adenosine 3':5'-monophosphate to Schizosaccharomyces pombe 972h- wild strain, to the glucose-super-repressed and derepressed mutants COB5 and COB6, and to Saccharomyces cerevisiae strain IL 216-IA. The mediated uptake of 2-D-deoxyglucose and the apparently nonmediated uptake of guanosine are not stimulated by the cyclic nucleotide. N6,O2'-Dibutyryl adenosine 3':5'-monophosphate is also efficient, whereas theophylline, guanosine 3':5'-monophosphate, 5'-AMP, ATP, and adenosine are ineffective. The cellular ATP content of glycerol-grown S. pombe COB5 is about 10 nmol per mg of protein and is not decreased by further incubation in the starvation medium. The addition of 100 mM glucose markedly enhances transport without any increase of the cellular ATP content. The addition of antimycin A or Dio-9 decreases markedly both cellular ATP content and transport. The addition of 2.5 mM glucose to antimycin A-containing medium restores both transport is not necessarily of mitochondrial origin. The uptake of 2-D-deoxyglucose is unaffected by the respiratory inhibitors. Stimulation of uptake by cyclic adenosine 3':5'-monophosphate occurs only in glucose-deprived cells. The addition of 10 mM glucose elicits the disappearance of the stimulation and prevents the 30% decrease of the cellular adenosine 3':5'-monophosphate content produced by glucose starvation. Adenosine 3':5'-'monophosphate does not enhance the steady state ATP level but requires cellular ATP produced either by endogenous respiration or, in the absence of respiration blocked by antimycin A, by further addition of 2.5 mM glucose. Stimulation of active uptake by adenosine 3':5'-monophosphate does not require protein synthesis because the addition of cycloheximide or anisomycin does not prevent the stimulation of L-leucine uptake. In the absence of respiration, Dio-9, and ATPase inhibitor, suppresses instantaneously the cellular ejection of protons as well as the uptake of uridine and amino acids. It abolishes also the adenosine 3':5'-monophosphate-stimulated transport. In the presence of antimycin A, specific mitochondrial ATPase inhibitors such as venruricidin A do not inhibit metabolite uptakes and their stimulation by adenosine 3':5'-monophosphate. These results suggest that in these conditions, the target of Dio-9 is not the mitochondrial ATPase but a plasma membrane proton-translocating function generating an electrochemical gradient required for active transport. That adenosine 3':5'-monophosphate enhances the Dio-9-sensitive proton extrusion supports the view that the cyclic nucleotide might modulate the plasma membrane ATPase.
 ...
PMID:Stimulation of active uptake of nucleosides and amino acids by cyclic adenosine 3' :5'-monophosphate in the yeast Schizosaccharomyces pombe. 16 26

1. The development of glycerolkinase before and after birth was investigated in liver and kidney of rat and hamster. In rat liver, enzyme activity increased very slowly before birth and rapidly thereafter, reaching adult values at the 6th day of postnatal life. In hamster liver, glycerolkinase was considerably elevated already in utero, increased dramatically within the 1st day of postnatal life and reached adult values at the end of the 1st week. The development of hepatic glycerolkinase was compared with that of hepatic phosphoenolpyruvate carboxykinase of rat and hamster up to the 20th day of postnatal life. The different time-courses of the levels of these two enzymes before and after birth as well as the known kinetics of serum insulin, glucagon and corticosterone during that time suggested that none of these hormones is involved in the perinatal development of hepatic glycerolkinase activity. In contrast to liver, kidney glycerolkinase activity in both, rat and hamster, showed a delayed increase during the first week of postnatal life followed by a more pronounced elevation to adult values within the following 2 weeks. 2. When liver and kidney glycerolkinase activity was investigated during starvation (+/- refeeding), in alloxan diabetes(+/- insulin) and after adrenalectomy (+/- cortisol) no significant change in enzyme activity per g tissue could be detected either in liver or in kidney. However, total hepatic glycerolkinase activity was diminished during starvation as a consequence of decreasing liver weight. 3. Incorporation of U-[14C]-glycerol into CO2, lipids and glucose + glycogen by rat liver and kidney cortex slices was studied under the above gluconeogenetic conditions. Despite unchanged glycerolkinase activity in both organs, gluconeogenesis from glycerol was enhanced during starvation and in chronic alloxan diabetes, and could be reversed by refeeding and insulin replacement, respectively. 4. Feeding 20% of linolic acid to normal, alloxan-diabetic or adrenalectomized rats resulted in a significant increase in glycerolkinase activity in liver but not in kidney. 5. From the present findings it is suggested that the first step of gluconeogenesis from glycerol in liver and kidney is not influenced by glucagon, insulin and glucocorticoids, which are generally believed to regulate the rate of gluconeogenesis from non-glycerol precursors, but probably by the change in blood glycerol concentration.
 ...
PMID:Glycerolkinase--a regulatory enzyme of gluconeogenesis? 18 91

Swine were fed equal amounts of isoenergetic-isonitrogenous diets with low-fat or high-fat content. The high-fat diet, as well as starvation, suppressed the synthesis of fatty acid from glucose in adipose tissue. Diet had no effect on adipose tissue enzymes associated with glyceride synthesis; whereas starvation caused all activities expressed per g tissue to decrease. The hepatic enzyme activities associated with glyceride synthesis tended to be greater in swine fed the the high-fat diet compared to the low-fat diet. Starvation lowered the hepatic esterification of glycerol-3-phosphate but did not influence other enzymes.
 ...
PMID:Effects of diet on swine glyceride lipid metabolism. 20 75

1. Male rats were injected daily for 5 days with 0.15m-NaCl, corticotropin, cortisol or l-thyroxine and the rates of glycerolipid synthesis were measured in the livers after intraportal injection of [(14)C]palmitate and [(3)H]glycerol. 2. Injection of all three hormones decreased the rates of body-weight gain. 3. Cortisol treatment increased the weight of the liver relative to body weight. 4. Thyroxine treatment increased the relative rate of triacylglycerol synthesis from [(3)H]glycerol and decreased the relative accumulation of (3)H and (14)C in diacylglycerol. It did not significantly alter the accumulation of these isotopes in phosphatidate nor the activity of the soluble phosphatidate phosphohydrolase in the total liver. However, this activity increased by 1.5-fold when expressed relative to the soluble protein of the liver. The increased triacylglycerol synthesis appears to be related to a general increase in the turnover of fatty acids in the liver. 5. Treatment with cortisol and corticotropin increased the relative rate of triacylglycerol synthesis from [(3)H]glycerol, decreased the accumulation of (3)H in phosphatidate and increased the flux of both isotopes from phosphatidate to diacylglycerol. This appeared to be caused by the increased activity of the soluble phosphatidate phosphohydrolase that was observed in the livers of the cortisol-treated rats. 6. It is proposed that cortisol could be directly or indirectly involved in increasing the activity of hepatic phosphatidate phosphohydrolase in starvation, diabetes, laparotomy, subtotal hepatectomy, liver damage, ethanol feeding and in obesity. This enzyme adaptation could contribute to the potential of the liver to increase its synthesis and accumulation of triacylglycerols or to secrete very-low-density lipoproteins.
 ...
PMID:The effects of cortisol, corticotropin and thyroxine on the synthesis of glycerolipids and on the phosphatidate phosphohydrolase activity in rat liver. 21 53

When either fructose, glycerol, or succinate served as a sole source of carbon and energy in nitrogen-starved cultures of Escherichia coli W4597(K) the values of the kinetic constants of the equation that expresses the relationship between glycogen synthesis and hexose phosphates were different from the values observed when glucose was the sole source of carbon and energy. Addition of glucose during either exponential growth or nitrogen starvation to a culture using one of the other carbon sources slowed the rate of glycogen synthesis and shifted the values of the constants toward the values observed in cultures using glucose alone. Addition of cyclic AMP (cyclic adenosine 3':5'-monophosphate) during exponential growth of a culture using glucose caused the values of the constants to be shifted toward the values observed in cultures using a carbon source other than glucose. In all of the metabolic conditions studied in this report the adenylate energy charge ((ATP + 1/2 ADP)/(ATP + ADP + AMP)) and the level of the rate-limiting enzyme of glycogen synthesis, ADP-glucose synthetase (glucose 1-phosphate adenylyltransferase, EC 2.7.7.27), were the same. The data presented here indicate that the difference we observed in the quantitative relationship for glycogen synthesis is the result of the different cellular levels of cyclic AMP in the cells using glucose and the cells using one of the other carbon sources. Since cyclic AMP does not affect the velocity of ADP-glucose synthetase in vitro, apparently a change in the cellular level of cyclic AMP causes a shift in the cellular level of a presently unknown (and previously undetected) effector of this enzyme. The shift in the level of this effector evidently alters the response of the enzyme in vivo to the substrate glucose 1-phosphate and the activator fructose 1,6-diphosphate.
 ...
PMID:Contribution of cyclic adenosine 3':5'-monophosphate to the regulation of bacterial glycogen synthesis in vivo. Effect of carbon source and cyclic adenosine 3':5'-monophosphate on the quantitative relationship between the rate of glycogen synthesis and the cellular concentrations of glucose 6-phosphate and fructose 1,6-diphosphate in Escherichia coli. 22 50


1 2 3 4 5 6 7 8 9 10 Next >>