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Amitraz depresses cardiovascular responses to bilateral carotid occlusion
Author(s) -
REYNOLDSON J. A.,
CULLEN L. K.
Publication year - 1996
Publication title -
journal of veterinary pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.527
H-Index - 60
eISSN - 1365-2885
pISSN - 0140-7783
DOI - 10.1111/j.1365-2885.1996.tb00003.x
Subject(s) - amitraz , baroreceptor , bradycardia , yohimbine , anesthesia , medicine , reflex bradycardia , reflex , blood pressure , heart rate , antagonist , chemistry , acaricide , receptor , organic chemistry
The ectoparasiticide amitraz stimulates α 2 ,‐adrenoceptors to produce side‐effects such as bradycardia and hypotension. The actions of amitraz on baroreceptor reflex responses were evaluated in mongrel dogs by occlusion of both carotid arteries for 30‐s periods. Incremental doses of amitraz given intravenously showed that doses of 60 μg/kg and above significantly depressed pressor responses to carotid occlusion. By comparison, 2 μg/kg amitraz given by intracisterna magna (i.c.m.) injection significantly depressed both blood pressure and heart rate responses. Pretreatment of dogs with i.c.m. yohimbine (30 μg/kg) prevented the depressant effects of amitraz on the reflex, but prazosin (20 μg/kg), in separate experiments, had no effect.