Activation of calcium ion-dependent proteinases by bradykinin in dental pulp of the rat.
The present study was aimed to examine whether BANA-degrading enzyme activities could be enhanced by bradykinin(BK) in dental pulp of the rat in vitro. The results showed that BK(0.1-10 microM) dose-dependently enhanced BANA-degrading enzyme activity at pH 7.4. The effects of BK(1 microM) were found to be most effective at both pH 7 and 8, with enhancement of the enzyme activities at a wide range of pH. The BK effects at both the pH were not inhibited by FOY-305(0.1 microM), an inhibitor of trypsin-like enzymes, differing from that at pH 6 in adrenal medulla of the rat. On the other hand, the effects of BK at both the pH were remarkably inhibited by EGTA (2 mM), followed by reversal with calcium ion (2.42 mM). These results suggested as follows: 1) there might be two kinds of BANA-degrading enzymes activated by BK in the pulp. 2) it was conceivable that BANA-degrading enzymes activated by BK were quite different from serine proteinases and were interfered with them in the pulp. 3) calcium ion might play a role in BK-induced enhancement of BANA-degrading enzyme activities which were regarded as met-enkephalin (ME) processing enzyme activities in the pulp.
Kudo
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Department of Pharmacology, Osaka University Faculty of Dentistry, Japan.
Wei
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Inoki
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D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology; D002154:Calpain / Q000378:metabolism*; D003782:Dental Pulp / Q000201:enzymology*; D004533:Egtazic Acid / Q000494:pharmacology; D004789:Enzyme Activation; D004952:Esters; D016670:Gabexate / Q000031:analogs & derivatives*; D006146:Guanidines / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D011480:Protease Inhibitors / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D004952:Esters; D006146:Guanidines; D011480:Protease Inhibitors; C034532:camostat; D016670:Gabexate; D004533:Egtazic Acid; D002154:Calpain; D001920:Bradykinin; D002118:Calcium