Choline administration reverses hypotension in spinal cord transected rats: the involvement of vasopressin.
Neurochem Res
; 23(5): 733-41, 1998 May.
Article
em En
| MEDLINE
| ID: mdl-9566613
ABSTRACT
Intracerebroventricular (i.c.v.) choline (50-150 microg) 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 microg; i.c.v.) blocked the pressor, bradycardic and vasopressin responses to choline (150 microg). Atropine pretreatment (10 microg; i.c.v.) abolished the bradycardia but failed to alter pressor and vasopressin responses. Hemicholinium-3 [HC-3 (20 microg; i.c.v.)] pretreatment attenuated both bradycardia and pressor responses to choline. The vasopressin V1 receptor antagonist, (beta-mercapto-beta,beta-cyclopenta-methylenepropionyl1, O-Me-Tyr2, Arg8)-vasopressin (10 microg/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.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Medula Espinal
/
Traumatismos da Medula Espinal
/
Pressão Sanguínea
/
Vasopressinas
/
Ventrículos Cerebrais
/
Colina
/
Frequência Cardíaca
/
Hipotensão
Tipo de estudo:
Etiology_studies
Limite:
Animals
Idioma:
En
Revista:
Neurochem Res
Ano de publicação:
1998
Tipo de documento:
Article