Effects of starvation on the maximal activities of some glycolytic and citric acid-cycle enzymes and glutaminase in mucosa of the small intestine of the rat

Budohoski, L; Challis, R. A. John; Newsholme, Eric A.

doi:10.1042/bj2060169

Cited by 31 publications

(20 citation statements)

References 22 publications

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“…All glassware was silicone-treated bolism in the whole animal (see Ruderman, 1975), before use. the effect of this condition on these enzyme activities has been measured to indicate possible changes of Graft-versus-host reaction fuel utilization and to compare the results with those Ford et al (1970) have established that the of a similar study on the rapidly dividing cells of the popliteal-lymph-node weight assay is more sensitive small intestine (Budohoski et al, 1982). Finally, the for indicating the extent of the graft-versus-host effect of a graft-versus-host reaction, used as a reaction in rats than is the spleen weight assay.…”

Section: 5) and 3-hydroxybutyratementioning

confidence: 99%

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Maximum activities of some enzymes of glycolysis, the tricarboxylic acid cycle and ketone-body and glutamine utilization pathways in lymphocytes of the rat

Ardawi

Newsholme

1982

Biochemical Journal

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207

114

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1. The maximum activity of hexokinase in lymphocytes is similar to that of 6-phosphofructokinase, but considerably greater than that of phosphorylase, suggesting that glucose rather than glycogen is the major carbohydrate fuel for these cells. Starvation increased slightly the activities of some of the glycolytic enzymes. A local immunological challenge in vivo (a graft-versus-host reaction) increased the activities of hexokinase, 6-phosphofructokinase, pyruvate kinase and lactate dehydrogenase, confirming the importance of the glycolytic pathway in cell division. 2. The activities of the ketone-body-utilizing enzymes were lower than those of hexokinase or 6-phosphofructokinase, unlike in muscle and brain, and were not affected by starvation. It is suggested that the ketone bodies will not provide a quantitatively important alternative fuel to glucose in lymphocytes. 3. Of the enzymes of the tricarboxylic acid cycle whose activities were measured, that of oxoglutarate dehydrogenase was the lowest, yet its activity (about 4.0mumol/min per g dry wt. at 37 degrees C) was considerably greater than the flux through the cycle (0.5mumol/min per g calculated from oxygen consumption by incubated lymphocytes). The activity was decreased by starvation, but that of citrate synthase was increased by the local immunological challenge in vivo. It is suggested that the rate of the cycle would increase towards the capacity indicated by oxoglutarate dehydrogenase in proliferating lymphocytes. 4. Enzymes possibly involved in the pathway of glutamine oxidation were measured in lymphocytes, which suggests that an aminotransferase reaction(s) (probably aspartate aminotransferase) is important in the conversion of glutamate into oxoglutarate rather than glutamate dehydrogenase, and that the maximum activity of glutaminase is markedly in excess of the rate of glutamine utilization by incubated lymphocytes. The activity of glutaminase is increased by both starvation and the local immunological challenge in vivo. This last finding suggests that metabolism of glutamine via glutaminase is important in proliferating lymphocytes.

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Section: 5) and 3-hydroxybutyratementioning

confidence: 99%

“…Results and discussion the absorptive cells of the intestine (Budohoski et al, 1982). The latter cells also possess glucose 6-Glycolysis phosphatase and fructose bisphosphatase activities, The activities of some of the glycolytic enzymes in which may play a role in the regulation of the lymphocytes are given in Table 1.…”

Section: Chemicals and Enzymesmentioning

confidence: 99%

Maximum activities of some enzymes of glycolysis, the tricarboxylic acid cycle and ketone-body and glutamine utilization pathways in lymphocytes of the rat

Ardawi

Newsholme

1982

Biochemical Journal

Self Cite

207

114

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“…The maximal activity of glutaminase in intestinal mucosa of female rats (measured in scrapings or the whole of the small intestine) is higher than those found for male rats [being 63.17+ 5.75 (n = 14) or 7.12+2.03 (n = 8) nmol/min per mg of protein measured in scrapings or whole of the small intestine of male rats respectively; see also Budohoski et al (1982), Watford et al (1984 and Ardawi (1986b)], and is presented in Table 1. A marked increase in the activity of glutaminase was evident in both late pregnancy and peak lactation, whether measured in intestinal scrapings or in the whole organ (Table 1).…”

Section: Intestinal Glutaminase Activitymentioning

confidence: 73%

The maximal activity of phosphate-dependent glutaminase and glutamine metabolism in late-pregnant and peak-lactating rats

Ardawi¹

1987

Biochemical Journal

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The maximal activity of phosphate-dependent glutaminase was increased in the small intestine, decreased in the liver and unchanged in the kidney of late-pregnant rats. This was accompanied by increases in the size of both the small intestine and the liver. The maximal activity of phosphate-dependent glutaminase was increased in both the small intestine and liver but unchanged in the kidney of peak-lactating rats. Enterocytes isolated from late-pregnant or peak-lactating rats exhibited an enhanced rate of utilization of glutamine and production of glutamate, alanine and ammonia. Arteriovenous-difference measurements across the gut showed an increase in the net glutamine removed from the circulation in late-pregnant and peak-lactating rats, which was accompanied by enhanced rates of release of glutamate, alanine and ammonia. Arteriovenous-difference measurements for glutamine showed that both renal uptake and skeletal-muscle release of glutamine were not markedly changed during late pregnancy or peak lactation; but pregnant rats showed a hepatic release of the amino acid. It is concluded that, during late pregnancy and peak lactation, the adaptive changes in glutamine metabolism by the small intestine, kidneys and skeletal muscle of hindlimb are similar; however, the liver appears to release glutamine during late pregnancy, but to utilize glutamine during peak lactation.

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“…This is in agreement with starvation-induced decreases in the activity of some glycolytic and citric acid-cycle enzymes in the intestine. 16 Furthermore, the down-regulation of glyceraldehyde-3-phosphate dehydrogenase and aldolase B can be explained by lysosomal proteolysis as both are substrates for chaperone-mediated autophagy, a process activated during nutrient limitation, 17 and probably also during starvation. We speculate that the reduction in the level of glycolytic enzymes is a direct effect of the diminished glucose supply to the intestine.…”

Section: Discussionmentioning

confidence: 99%

Starvation Induces Phase-Specific Changes in the Proteome of Mouse Small Intestine

et al. 2006

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Food deprivation results in metabolic, structural, and functional changes in the small intestine that influences gut mucosal integrity, epithelial cell proliferation, mucin synthesis, and other processes. The underlying mechanisms are still unclear, which lead to the study of molecular effects of shortterm and long-term starvation in the intestine of mice. A comparative proteomics approach, combining two-dimensional gel electrophoresis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, was used to identify intestinal proteins whose expression is changed under different starvation conditions (0, 12, 24, and 72 h). In total, the expression levels of 80 protein spots changed significantly between the different groups. The results demonstrate that after 12 h of starvation, mainly proteins involved in glycolysis and energy metabolism show decreased expression levels. Starvation for 24 h results in a down-regulation of proteins involved in protein synthesis and amino acid metabolism. Simultaneously, proteins with a protective role, e.g., reg I and II, glutathione peroxidase 3, and carbonic anhydrase 3, are clearly up-regulated. The last starvation phase (72 h) is characterized by increased ezrin expression, which may enhance villus morphogenesis critical for survival. Together, these results provide novel insights in the intestinal starvation response and may contribute to improved nutritional support during conditions characterized by malnutrition.Keywords: short-term food deprivation • long-term food deprivation • protein profiling • intestinal adaptation • lithostathine 1 and 2 (reg I and II) • ezrin expression

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Effects of starvation on the maximal activities of some glycolytic and citric acid-cycle enzymes and glutaminase in mucosa of the small intestine of the rat

Cited by 31 publications

References 22 publications

Maximum activities of some enzymes of glycolysis, the tricarboxylic acid cycle and ketone-body and glutamine utilization pathways in lymphocytes of the rat

Maximum activities of some enzymes of glycolysis, the tricarboxylic acid cycle and ketone-body and glutamine utilization pathways in lymphocytes of the rat

The maximal activity of phosphate-dependent glutaminase and glutamine metabolism in late-pregnant and peak-lactating rats

Starvation Induces Phase-Specific Changes in the Proteome of Mouse Small Intestine

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