Data/hora: 01/06/2024 02:21:12

Provedor de dados: | 56
País: | Brazil
Título: | Acute blood volume expansion delays the gastrointestinal transit of a charcoal meal in awake rats
Autores: | de-Oliveira,G.R.; Gondim,F. de-A.A.; da-Graça,J.R.V.; Xavier-Neto,J.; Dantas,R.P.; Gondim,R.B.M.; Santos,A.A.; Rola,F.H.
Data: | 1998-06-01
Ano: | 1998
Palavras-chave: | Hypervolemia; Blood volume; Gastrointestinal transit; Rats; Gastrointestinal motility.
Resumo: | The present study evaluates the effect of blood volume expansion on the gastrointestinal transit of a charchoal 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 iv 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&amp;lt;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&amp;lt;0.05). Mean arterial pressure increased transiently and central venous pressure increased and hematocrit decreased (P&amp;lt;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.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000600017
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X1998000600017
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.31 n.6 1998
Fonte: | info:eu-repo/semantics/openAccess