Journal of cardiovascular pharmacology
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J. Cardiovasc. Pharmacol. · Nov 1997
Cardiovascular effects of central choline during endotoxin shock in the rat.
The cardiovascular effects of intracerebroventricular (i.c.v.) administration of choline were studied in endotoxin-treated rats. Intravenous (i.v.) endotoxin (20 mg/kg) caused a moderate hypotension and tachycardia within 10 min of treatment. Choline (50, 100, and 150 microg; i.c.v.) increased blood pressure and decreased heart rate in this condition in a dose-dependent manner. ⋯ The vasopressin receptor antagonist, (beta-mercapto-beta,beta-cyclopentamethylene-propionyl(1)-O-Me-Tyr2,Arg8 )-vasopressin (10 microg/kg; i.v.) administered 5 min after choline decreased blood pressure from the increased level to the precholine levels but did not alter bradycardia. These results indicate that, in rats treated with endotoxin, choline increases blood pressure and decreases heart rate by a presynaptic mechanism leading to the activation of central nicotinic cholinergic pathways. An increase in plasma vasopressin levels seems to be involved in the pressor, but not in the bradycardic response, to choline.