ISSN:
1573-6903
Keywords:
Choline
;
acetylcholine
;
vasopressin
;
blood pressure
;
hypotension
;
spinal shock
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Intracerebroventricular (i.c.v.) choline (50–150 μg) increased blood pressure and decreased heart rate in spinal cord transected, hypotensive rats. Choline administered intraperitoneally (60 mg/kg), also, increased blood pressure, but to a lesser extent. The pressor response to i.c.v. choline was associated with an increase in plasma vasopressin. Mecamylamine pretreatment (50 μg; i.c.v.) blocked the pressor, bradycardic and vasopressin responses to choline (150 μg). Atropine pretreatment (10 μg; i.c.v.) abolished the bradycardia but failed to alter pressor and vasopressin responses. Hemicholinium-3 [HC-3 (20 μg; i.c.v.)] pretreatment attenuated both bradycardia and pressor responses to choline. The vasopressin V1 receptor antagonist, (β-mercapto-β, β-cyclopenta-methylenepropionyl1, O-Me-Tyr2, Arg8)-vasopressin (10 μg/kg) administered intravenously 5 min after choline abolished the pressor response and attenuated the bradycardia-induced by choline. These data show that choline restores hypotension effectively by activating central nicotinic receptors via presynaptic mechanisms, in spinal shock. Choline-induced bradycardia is mediated by central nicotinic and muscarinic receptors. Increase in plasma vasopressin is involved in cardiovascular effects of choline.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1022407409727
