ENDOTOXIN TEMPORARILY IMPAIRS CANINE COLONIC ABSORPTION OF WATER AND SODIUM

Diarrhea is a common manifestation of sepsis. We hypothesized that end otoxin may impair colonic absorption of water and electrolytes, an eff ect which may be related to altered liquid transit in the colon. Five dogs underwent construction of 50-cm colonic Thiry-Vella fistulas (TVF ). Following recovery, absorption studies were performed by perfusing the TVF with an isotonic solution at 2.9 ml/min containing polyethylen e glycol (5 g/L). Fasting and postprandial colonic absorption of water , electrolytes, and glucose were deter mined, Liquid transit was asses sed by bolus of a nonabsorbable marker (PSP) instilled into the proxim al end of the TVF, Following completion of the baseline studies, each dog was given a single dose of Escherichia coli lipopolysaccharide 200 mu g/kg iv and the studies were repeated daily for the next 3 days. F ollowing endotoxin bolus, colonic absorption of water and sodium were decreased during fasting, while postprandial colonic absorption of wat er was also decreased, Colonic absorption of water and sodium returned to baseline values on postendotoxin day 2. Colonic secretion of potas sium was decreased on postendotoxin days 1 and 3 in both the fasting a nd the fed periods. Fasting and postprandial liquid transit was also r apid on postendotoxin day 1, which correlated with the decreased absor ption seen on that day. Liquid transit returned to baseline values on postendotoxin day 2, We conclude that endotoxin temporarily impairs po stprandial colonic absorption, which may be due to the rapid liquid tr ansit that occurs. These effects may contribute to the diarrhea seen d uring and after septic episodes. (C) 1998 Academic Press.