Small intestinal fluid absorption in the rat during haemorrhage and its importance for plasma refill.
Small intestinal net fluid absorption and its importance for plasma volume restitution during a slow, stepwise haemorrhage was studied in rats. A continuous administration of a Krebs-glucose solution into the intestinal lumen increased the tolerated maximal bleeding volume from 31 to 70% of initial total blood volume. The 'small intestinal' autotransfusion rate, i.e. the rate of fluid mobilized from the intestinal lumen into the vascular compartment, was calculated to 2.3 ml h-1 100 cm-2 small intestinal serosal surface. 'Small intestinal' autotransfusion is proposed to be an important mechanism in the defence line against hypovolaemia. Haemorrhage induced a 40% increase in small intestinal net fluid absorption. This increase was abolished after pretreatment with Captopril, an angiotensin-converting enzyme blocker. Post-ganglionic denervation of the small intestine reduced, but did not abolish, the stimulatory effect of haemorrhage on net fluid absorption. These results indicate that both a direct nervous component and the renin-angiotensin system are of importance for the increase in small intestinal net fluid absorption observed after haemorrhage.
Department of Physiology, University of Göteborg, Sweden.
S
S
Redfors
D000136:Acid-Base Equilibrium; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003714:Denervation; D005260:Female; D006439:Hemodynamics; D006470:Hemorrhage / Q000378:metabolism* / Q000503:physiopathology; D007408:Intestinal Absorption; D007421:Intestine, Small / Q000294:innervation / Q000378:metabolism*; D008297:Male; D010953:Plasma Volume; D051381:Rats; D011919:Rats, Inbred Strains; D014882:Water-Electrolyte Balance
D001786:Blood Glucose