R A Challis

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The mechanisms by which N-methyl-D-aspartate (NMDA) receptor activation can modulate muscarinic receptor-stimulated phosphoinositide turnover have been studied in neonatal rat cerebral cortex slices. A maximally effective concentration of carbachol (1 mM) caused a large stimulation of both total [3H]inositol phosphate ([3H]InsPx) accumulation (30-40-fold(More)
In previous studies it has been shown that both bradykinin and histamine increase the formation of 3H-labeled inositol phosphates in adrenal chromaffin cells prelabelled with [3H]inositol and that both these agonists stimulate release of catecholamines by a mechanism dependent on extracellular calcium. Here, we have used mass assays of inositol(More)
Starvation decreases activities of some glycolytic and citric acid-cycle enzymes, and increases those of glucose 6-phosphatase and fructose bisphosphatase, whereas that of glutaminase is unchanged. These findings may be of significance for the control of glucose metabolism in the absorptive cells of the intestine.
The effects of cold-exposure, the hyperthyroid state and a single exercise bout in vivo on the maximal enzyme activities of 6-phosphofructokinase and fructose-1,6-bisphosphatase in vastus lateralis muscle and the rates of fructose 6-phosphate/fructose 1,6-bisphosphate cycling measured in epitrochlearis muscle in vitro were investigated. In all cases(More)
The decreased sensitivity of glycolysis to insulin seen in isolated soleus muscles from genetically obese Zucker rats was abolished by addition of the adenosine-receptor antagonist 8-phenyltheophylline to the incubation medium; 8-phenyltheophylline had no effect on the sensitivity of glycogen synthesis to insulin. These findings suggest that changes in the(More)
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