TY - JOUR
T1 - Vasopressin receptor mediated contraction and [3H]inositol metabolism in rat tail artery
AU - Fox, Anthony W.
AU - Friedman, Paul A.
AU - Abel, Peter W.
PY - 1987/3/3
Y1 - 1987/3/3
N2 - Inositol phosphates (IP) production and contraction in isolated but otherwise intact rat tail artery were measured in response to stimulation by vasopressin agonists. We have previously studied similar α-adrenoceptor responses. Identical rank orders of vasopressin agonists' potency were found for IP accumulation and contraction. The vasopressin analogue [1-(β-mercapto-β,β-cyclopentamethylene proprionic acid)-2-(O-methyl)tyrosine,D-arginine8] vasopressin, was shown to be a specific, reversible antagonist for both IP accumulation and contraction by all vasopressin agonists tested. No antagonism of vasopressin induced increases in IP accumulation or contraction were found using phenoxybenzamine. Therefore, (i) in this tissue vasopressin receptors mediate both contraction and IP accumulation; and (ii) vasopressin mediated responses appear to be direct effects not mediated via the activation of α-adrenoceptors. Demonstration of two entirely different receptors, mediating the same functional response, and which both promote IP production, is consistent with a general obligatory role for phosphoinositide catabolism in receptor mediated vascular smooth muscle contraction.
AB - Inositol phosphates (IP) production and contraction in isolated but otherwise intact rat tail artery were measured in response to stimulation by vasopressin agonists. We have previously studied similar α-adrenoceptor responses. Identical rank orders of vasopressin agonists' potency were found for IP accumulation and contraction. The vasopressin analogue [1-(β-mercapto-β,β-cyclopentamethylene proprionic acid)-2-(O-methyl)tyrosine,D-arginine8] vasopressin, was shown to be a specific, reversible antagonist for both IP accumulation and contraction by all vasopressin agonists tested. No antagonism of vasopressin induced increases in IP accumulation or contraction were found using phenoxybenzamine. Therefore, (i) in this tissue vasopressin receptors mediate both contraction and IP accumulation; and (ii) vasopressin mediated responses appear to be direct effects not mediated via the activation of α-adrenoceptors. Demonstration of two entirely different receptors, mediating the same functional response, and which both promote IP production, is consistent with a general obligatory role for phosphoinositide catabolism in receptor mediated vascular smooth muscle contraction.
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U2 - 10.1016/0014-2999(87)90751-5
DO - 10.1016/0014-2999(87)90751-5
M3 - Article
C2 - 2952516
AN - SCOPUS:0023136228
VL - 135
SP - 1
EP - 10
JO - European Journal of Pharmacology
JF - European Journal of Pharmacology
SN - 0014-2999
IS - 1
ER -