Your browser doesn't support javascript.
loading
Acute blood volume expansion delays the gastrointestinal transit of a charcoal meal in awake rats.
de-Oliveira, G R; Gondim, F A; da-Graça, J R; Xavier-Neto, J; Dantas, R P; Gondim, R B; Santos, A A; Rola, F H.
Afiliação
  • de-Oliveira GR; Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Brasil.
Braz J Med Biol Res ; 31(6): 835-40, 1998 Jun.
Article em En | MEDLINE | ID: mdl-9698831
The present study evaluates the effect of blood volume expansion on the gastrointestinal transit of a charcoal meal (2.5 ml of an aqueous suspension consisting of 5% charcoal and 5% gum arabic) in awake male Wistar rats (200-270 g). On the day before the experiments, the rats were anesthetized with ether, submitted to left jugular vein cannulation and fasted with water ad libitum until 2 h before the gastrointestinal transit measurement. Blood volume expansion by i.v. infusion of 1 ml/min Ringer bicarbonate in volumes of 3, 4 or 5% body weight delayed gastrointestinal transit at 10 min after test meal administration by 21.3-26.7% (P < 0.05), but no effect was observed after 1 or 2% body weight expansion. The effect of blood volume expansion (up to 5% body weight) on gastrointestinal transit lasted for at least 60 min (P < 0.05). Mean arterial pressure increased transiently and central venous pressure increased and hematocrit decreased (P < 0.05). Subdiaphragmatic vagotomy and yohimbine (3 mg/kg) prevented the delay caused by expansion on gastrointestinal transit, while atropine (0.5 mg/kg), L-NAME (2 mg/kg), hexamethonium (10 mg/kg), prazosin (1 mg/kg) or propranolol (2 mg/kg) were ineffective. These data show that blood volume expansion delays the gastrointestinal transit of a charcoal meal and that vagal and yohimbine-sensitive pathways appear to be involved in this phenomenon. The delay in gastrointestinal transit observed here, taken together with the modifications of gastrointestinal permeability to salt and water reported by others, may be part of the mechanisms involved in liquid excess management.
Assuntos
Buscar no Google
Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Volume Sanguíneo / Trânsito Gastrointestinal / Carvão Vegetal Limite: Animals Idioma: En Revista: Braz J Med Biol Res Ano de publicação: 1998 Tipo de documento: Article País de afiliação: Brasil País de publicação: Brasil
Buscar no Google
Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Volume Sanguíneo / Trânsito Gastrointestinal / Carvão Vegetal Limite: Animals Idioma: En Revista: Braz J Med Biol Res Ano de publicação: 1998 Tipo de documento: Article País de afiliação: Brasil País de publicação: Brasil