Acute extracellular fluid volume changes increase ileocolonic resistance to saline flow in anesthetized dogs.
Braz J Med Biol Res
; 30(8): 999-1008, 1997 Aug.
Article
em En
| MEDLINE
| ID: mdl-9361731
We determined the effect of acute extracellular fluid volume changes on saline flow through 4 gut segments (ileocolonic, ileal, ileocolonic sphincter and proximal colon), perfused at constant pressure in anesthetized dogs. Two different experimental protocols were used: hypervolemia (iv saline infusion, 0.9% NaCl, 20 ml/min, volume up to 5% body weight) and controlled hemorrhage (up to a 50% drop in mean arterial pressure). Mean ileocolonic flow (N = 6) was gradually and significantly decreased during the expansion (17.1%, P < 0.05) and expanded (44.9%, P < 0.05) periods while mean ileal flow (N = 7) was significantly decreased only during the expanded period (38%, P < 0.05). Mean colonic flow (N = 7) was decreased during expansion (12%, P < 0.05) but returned to control levels during the expanded period. Mean ileocolonic sphincter flow (N = 6) was not significantly modified. Mean ileocolonic flow (N = 10) was also decreased after hemorrhage (retracted period) by 17% (P < 0.05), but saline flow was not modified in the other separate circuits (N = 6, 5 and 4 for ileal, ileocolonic sphincter and colonic groups, respectively). The expansion effect was blocked by atropine (0.5 mg/kg, i.v.) both on the ileocolonic (N = 6) and ileal (N = 5) circuits. Acute extracellular fluid volume retraction and expansion increased the lower gastrointestinal resistances to saline flow. These effects, which could physiologically decrease the liquid volume being supplied to the colon, are possible mechanisms activated to acutely balance liquid volume deficit and excess.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cloreto de Sódio
/
Espaço Extracelular
/
Motilidade Gastrointestinal
/
Anestesia
Limite:
Animals
Idioma:
En
Revista:
Braz J Med Biol Res
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Brasil