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CARDIOVASCULAR RESPONSES PRODUCED BY THE INJECTION OF DOPAMINE INTO THE CEREBRAL VENTRICLES OF THE UNANAESTHETIZED DOG
Author(s) -
LANG W.J.,
WOODMAN O.L.
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.tb13671.x
Subject(s) - phentolamine , dopamine , hexamethonium , medicine , dopamine receptor , endocrinology , propranolol , dopamine antagonist , heart rate , haloperidol , anesthesia , blood pressure , atropine
1 The injection of dopamine (100 to 500 μg) into the cerebral ventricles (i.c.v.) of 10 unanaesthetized dogs produced a dose‐dependent increase in arterial blood pressure and heart rate. The dogs licked, swallowed, sometimes vomited and became sedated. 2 Autonomic ganglion blockade with hexamethonium (10 mg/kg, i.v.) abolished cardiovascular responses to i.c.v. dopamine, indicating that dopamine was exerting its effect within the central nervous system. 3 The dopamine receptor antagonists, haloperidol (500 μg), chlorpromazine (200 μg) and ergometrine (500 μg), each given i.c.v., subsequently abolished the cardiovascular responses to dopamine. 4 Pretreatment with either the β‐adrenoceptor antagonist, propranolol (600 μg) or the α‐adrenoceptor antagonist, phentolamine (1 mg) given i.c.v. had no significant effect on the response to dopamine. 5 It is suggested that dopamine injected into the cerebral ventricles of the unanaesthetized dog causes hypertension and tachycardia by activating central dopamine receptors.