title: Inhibition of the enzymatic degradation of Met-enkephalin by catecholamines.
abstract: The influence of the catecholamine hormones and some of their metabolites on the enzymatic degradation of met-enkephalin by rat brain homogenates has been evaluated. The enzyme activity was determined by the release of [125I]-tyrosine from radioiodinated met-enkephalin following Porapak Q column chromatography. Each of the biologically active catecholamines inhibited the measured enzyme activity, and dose-response curves indicated that dopamine was most effective and epinephrine least effective. At 5 x 10(-5)M the O-methylated metabolite of each hormone failed to inhibit the enzyme activity. An enzyme activity similar to that found in brain was also found in adrenal and ileal homogenates. This enzyme activity was strongly inhibited by dopamine as well as by puromycin.
mesh_terms: D000311:Adrenal Glands / Q000187:drug effects / Q000201:enzymology*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology*; D002395:Catecholamines / Q000494:pharmacology*; D004298:Dopamine / Q000494:pharmacology; D004723:Endorphins / Q000378:metabolism*; D004744:Enkephalin, Methionine; D004745:Enkephalins / Q000378:metabolism*; D005260:Female; D007082:Ileum / Q000187:drug effects / Q000201:enzymology*; D011691:Puromycin / Q000494:pharmacology; D051381:Rats
chemical_list: D002395:Catecholamines; D004723:Endorphins; D004745:Enkephalins; D011691:Puromycin; D004744:Enkephalin, Methionine; D004298:Dopamine