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Cardiovascular and respiratory effects of cannabis in cat and rat
Author(s) -
GRAHAM J. D. P.,
LI D. M. F.
Publication year - 1973
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.1476-5381.1973.tb08262.x
Subject(s) - bradycardia , anesthesia , tetrahydrocannabinol , blood pressure , reflex bradycardia , atropine , vasoconstriction , medicine , reflex , respiratory system , respiratory rate , hindlimb , heart rate , vasodilation , cannabinoid , receptor
Summary1 In anaesthetized rats, intravenous administration of cannabis extract (10 mg/kg), Δ 1 ‐tetrahydrocannabinol (THC) (0·5 mg/kg) and Δ 6 ‐THC (0·5 mg/kg) caused a reduction in systemic blood pressure, pulse rate and respiratory rate. 2 Neither cannabinol (1 mg/kg, i.v.) nor cannabidiol (1 mg/kg, i.v.) had any observed effects on the cardiovascular and respiratory systems of the rat. 3 Pretreatment of rats with atropine (1 mg/kg, i.v.) reduced the hypotension and bradycardia caused by Δ 1 ‐THC or the extract. 4 In anaesthetized cats with autoperfused hindquarters, cannabis extract (10 mg/kg, i.v.) and Δ 1 ‐THC (0·2 mg/kg, i.v.) caused hypotension, bradycardia, depression of respiratory rate and reduction of hindlimb perfusion pressure. 5 Both cannabis extract and Δ 1 ‐THC potentiated reflex vasodilatation and direct vasoconstriction in the hindlimb induced by intravenous noradrenaline in the cat; they reduced reflex hindlimb vasoconstriction elicited by histamine, acetylcholine or bilateral carotid occlusion. 6 Tolerance to these cardiovascular and respiratory effects of cannabis extract developed in rats which had been treated i.p. with the extract at (50 mg/kg) per day for 14 days.