Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0848237 (acute stress)
 4,619 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been proposed that enkephalins play a role in stress phenomena. However, little is known concerning the effect of stress on the enzymes that may control the enkephalinergic activity. In the present paper we report the changes, after acute and chronic swimming-to-exhaustion stressor, of Tyr-aminopeptidase (which cleave the Tyr-Gly amide-bond) in discrete areas of the rat brain. After acute stress, only significant decreases in the striatum were observed. After chronic application, decreases in the striatum and increases in the hypothalamus and the medulla were seen.
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PMID:Effect of swimming-to-exhaustion stress on the Tyr-aminopeptidase activity in different brain areas of the rat. 808

Brain enkephalin and oxytocin are anxiolytic agents involved in the response mechanism to stress. Degrading enzymes such as enkephalinase and oxytocinase could also be associated with this response. The effect of acute immobilization stress on enkephalinase and oxytocinase activities was determined in the soluble and membrane fractions of the medial prefrontal cortex, hippocampus and amygdala using alanyl- and leucyl-beta-naphthylamide as substrates, the latter in the presence and absence of 20 mM L-methionine. No change in aminopeptidase activities was observed in the prefrontal cortex of stressed rats. In contrast, enkephalinase activity decreased in the soluble fraction of the hippocampus but increased in the membrane fraction. In the amygdala, soluble oxytocinase and membrane enkephalinase activities decreased in stressed animals. These results show that acute immobilization stress affects differentially enkephalinase and oxytocinase activities depending on the fraction and brain region analyzed. A reduction in the activity of soluble enkephalinase in the hippocampus and soluble oxytocinase as well as membrane enkephalinase in the amygdala may suggest higher availability/longer action of enkephalin and oxytocin at these locations. This may explain the relative importance of these enzymatic activities in the anxiolytic properties proposed for enkephalins and oxytocin in the hippocampus and amygdala during stress conditions. This interpretation is not applicable to membrane enkephalinase activity in the hippocampus. However, alanyl-beta-naphthylamide hydrolyzing activity not only measures enkephalinase activity, it also reflects the angiotensinase-induced metabolism of angiotensin III to angiotensin IV. Therefore, our results may also mirror an increase in the formation of Ang IV in hippocampus and a decrease in the amygdala in acute stress. In conclusion, aminopeptidase activities in the hippocampus and amygdala may affect enkephalin, oxytocin and angiotensin III metabolism during acute immobilization stress and therefore be involved in the anxiolytic response.
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PMID:Stress influences brain enkephalinase, oxytocinase and angiotensinase activities: a new hypothesis. 1946 42