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The actions of prostaglandins E 1 and F 2α on the perfused vessels of the isolated rabbit ear
Author(s) -
TAI SUHAILA A. AL,
GRAHAM J. D. P.
Publication year - 1972
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1972.tb07308.x
Subject(s) - phentolamine , endocrinology , medicine , reserpine , theophylline , aminophylline , dilator , vasodilation , propranolol , chemistry , vasopressin , perfusion , tolazoline , norepinephrine , papaverine , biology , dopamine
Summary1 In the isolated rabbit ear vascular bed, perfused with Krebs solution, prostaglandins E 1 and F 2α produce dose‐dependent, phentolamine‐sensitive constrictions. 2 These are absent if the animal is pre‐treated with reserpine or if the ear is denervated in advance. 3 If noradrenaline or vasopressin is added to the Krebs solution, vascular resistance is high and PGE 1 and PGF 2α produce vasodilatation which is unaffected by hyoscine or propranolol. 4 Perfusion with theophylline, with added ATP, ADP or 3′5′‐AMP, or pre‐treatment of the animal with stilboestrol antagonizes the dilator response to PGE 1 in the presence of noradrenaline, which may be reversed. Most of the responses to PGF 2α are reversed. These treatments elevate the level of 3′5′‐AMP in tissues. 5 It is postulated that prostaglandins exert a regulatory action on 3′5′‐AMP levels through inhibition of adenyl cyclase and/or phosphodiesterase and that the resulting rising or falling level of 3′5′‐AMP determines the nature of the response by the smooth muscle to the released noradrenaline.