Inhibitors of peptidases: how they influence the biological activities of substance P, neurokinins, bradykinin and angiotensin in guinea pig, hamster and rat urinary bladders.
Neurokinins, bradykinin and angiotensins were tested in isolated urinary bladder of the guinea pig, the hamster and the rat, in the absence and in presence of a variety of peptidase inhibitors in order to establish if peptide degradation interferes with the bladder contractions elicited by the three types of peptides. Indeed, the effects of neurokinins, bradykinin and angiotensin I in the guinea pig bladder were significantly enhanced by captopril (4.6 x 10(-6) mol/l), chymostatin (1 mg/l), phosphoramidon (4.6 x 10(-6) mol/l) and thiorphan (1.0 x 10(-6) mol/l), while only captopril was found to potentiate the effects of the same peptides in the rat bladder. The four peptidase inhibitors, as well as bacitracin were found to modify the responses of the hamster urinary bladder to one or another or to all three groups of peptides and to DiMeC7. The present results suggest that the urinary bladders of various species have different types of active proteolytic enzymes: only the angiotensin-converting enzyme appears to be present in the rat bladder, while the same enzyme and possibly two additional endopeptidases interfere with the myotropic effects of neurokinins, kinins and angiotensins in the guinea pig and the hamster bladder.
Department of Pharmacology, Medical School, University of Sherbrooke, Que., Canada.
N
N
Rouissi
F
F
Nantel
G
G
Drapeau
N E
NE
Rhaleb
S
S
Dion
D
D
Regoli
D000804:Angiotensin II / Q000037:antagonists & inhibitors*; D000818:Animals; D006224:Cricetinae; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007705:Kinins / Q000037:antagonists & inhibitors*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D015288:Neurokinin A / Q000037:antagonists & inhibitors; D015287:Neurokinin B / Q000037:antagonists & inhibitors; D011480:Protease Inhibitors / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000037:antagonists & inhibitors*; D001743:Urinary Bladder / Q000187:drug effects
D007705:Kinins; D011480:Protease Inhibitors; D000804:Angiotensin II; D013373:Substance P; D015288:Neurokinin A; D015287:Neurokinin B