Enhancement of proteinase activities by bradykinin in adrenal medulla of the rat.
In the present study, a significant positive correlationship was found between the contents of bradykinin (BK)-like and met-enkephalin(ME)-like peptides in adrenal medulla of the rat with cavity-formed incisors in vivo, and the production of ME-like peptides was increased by BK in adrenal medulla of the rat in vitro. Influence of BK on the degradation of BANA, a synthetic substrate for trypsin, by the tissue enzymes was also studied. It was found that BK (0.1-10 microM) enhanced the enzyme activities in a dose-dependent manner, and the effect of BK(1 microM) was most effective at pH 6 and 8. The BK effect was inhibited by FOY-305, an inhibitor of serine proteinases, at pH 6, but not at pH 8. However, E-64, an inhibitor of cysteine proteinases, reduced the BK effects at both pH 6 and 8. These results suggested that 1) BK was an activator for BANA-degrading enzymes which were thought as processing proteinases of ME-like peptides in adrenal medulla of the rat, and 2) there may be, at least, two kinds of BANA-degrading enzymes activated by BK, one might be a serine proteinase with optimal pH at 6, and the others might be cysteine proteinases with optimal pH at both 6 and 8.
Wei
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Department of Pharmacology, Osaka University Faculty of Dentistry, Japan.
Kudo
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Inoki
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D000313:Adrenal Medulla / Q000201:enzymology*; D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D004744:Enkephalin, Methionine / Q000378:metabolism; D004952:Esters; D016670:Gabexate / Q000031:analogs & derivatives*; D006146:Guanidines / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D010447:Peptide Hydrolases / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D004952:Esters; D006146:Guanidines; D011480:Protease Inhibitors; C034532:camostat; D016670:Gabexate; D004744:Enkephalin, Methionine; D010447:Peptide Hydrolases; D001920:Bradykinin