title: Kinin receptors and angiotensin converting enzyme in rabbits basilar arteries.
abstract: Bradykinin (BK) initially produced concentration related relaxations of the rabbit basilar artery in vitro under resting tension and when contracted with 5-hydroxytryptamine. Concentration-effect (C-E) curves to BK repeated at 2 h intervals over an 8-10 h period resulted in the production of progressively increased contractile responses. The induction of these contractile responses to BK was prevented by pre-incubation of these tissues with cycloheximide. On tissues which had been challenged with BK at 2 h intervals for 8 h in the absence of cycloheximide the rank order of potency of three kinins to produce contraction was methionyl-lysyl-BK (M-L-BK) greater than BK greater than des-Arg9-BK. On the same tissues the specific B1-receptor antagonist des-Arg9-Leu8-BK inhibited the contractile effects of BK. These results suggest the presence of a B1-receptor mediating contraction. The rank order of potency of the kinins to produce relaxation of tissues preincubated with cycloheximide was BK greater than M-L-BK greater than des-Arg9-BK which suggests the presence of a B2-receptor mediating these responses. Angiotensin I (AI) and angiotensin II (AII) produced concentration related contractions of the tissue. The angiotensin converting enzyme inhibitors captopril, BPP5a and BPP9a inhibited responses to AI but had no effect on contractile C-E curves to BK, AII and 5-HT or on relaxant C-E curves to BK. These results suggest that the rabbit basilar artery in vitro contains two BK receptors, a B1 receptor mediating contraction and a B2 receptor mediating relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000803:Angiotensin I / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001488:Basilar Artery / Q000187:drug effects*; D001920:Bradykinin / Q000031:analogs & derivatives / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology; D005260:Female; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D011817:Rabbits; D018002:Receptors, Bradykinin; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology; D013997:Time Factors
chemical_list: D018002:Receptors, Bradykinin; D011956:Receptors, Cell Surface; D000804:Angiotensin II; C024626:bradykinin, des-Arg(9)-; D012701:Serotonin; C018103:bradykinin, Met-Lys-; D000803:Angiotensin I; D003513:Cycloheximide; D007703:Peptidyl-Dipeptidase A; D001920:Bradykinin