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URETHANE AND CONTRACTION OF VASCULAR SMOOTH MUSCLE
Author(s) -
ALTURA BURTON M.,
WEINBERG JULIO
Publication year - 1979
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.1476-5381.1979.tb08674.x
Subject(s) - contraction (grammar) , vascular smooth muscle , inhibitory postsynaptic potential , muscle contraction , chemistry , pharmacology , aorta , blood vessel , angiotensin ii , medicine , portal vein , muscle relaxation , smooth muscle , anesthesia , endocrinology , blood pressure
1 In vitro studies were undertaken on rat aortic strips and portal vein segments in order to determine whether or not the anaesthetic, urethane, can exert direct actions on vascular smooth muscle. 2 Urethane was found to inhibit development of spontaneous mechanical activity. This action took place with a urethane concentration as little as one tenth of that found in anaesthetic plasma concentrations, i.e., 10 −3 m . 3 Urethane (10 −3 to 10 −1 m ) dose‐dependently attenuated contractions induced by adrenaline, angiotensin and KCl. These inhibitory actions were observed with urethane added either before or after the induced contractions. 4 Ca 2+ ‐induced contractions of K + ‐depolarized aortae and portal veins were also attenuated, dose‐dependently, by urethane. 5 All of these inhibitory effects were completely, and almost immediately, reversed upon washing out the anaesthetic from the organ baths. 6 A variety of pharmacological antagonists failed to mimic or affect the inhibitory effects induced by urethane. 7 These data suggest that plasma concentrations of urethane commonly associated with induction of surgical anaesthesia can induce, directly, relaxation of vascular muscle.