AJP - Gastrointestinal and Liver Physiology, Vol 242, Issue 6 642-G649, Copyright © 1982 by American Physiological Society
Glucose absorption by in vitro perfused ileum of the fetal rat
G. D. Potter, K. L. Schmidt, R. Lester and S. G. Schultz
In vitro intraluminal perfusion of the fetal rat ileum at 19 and 20 days of
gestation was employed to measure the rate of glucose absorption and the
unidirectional fluxes of 3-O-methylglucose (3-O-MG). Fetal ileum was
mounted on pipettes within an oxygenated bath and perfused with a solution
containing glucose or 3-O-MG and polyethylene glycol with average molecular
weight of 4,000 (PEG) as a marker substance. We verified that the PEG was
not transported and did not diffuse across the fetal ileum. Scanning and
electron microscopy before and after perfusion demonstrated preservation of
mucosal anatomy. The rate of glucose absorption was 200 +/- 17
mumol.h-1.g-1 at 19 days and increased significantly to 378 +/- 12
mumol.h-1.g-1 at 20 days. The absence of sodium abolished this process. The
flux of 3-O-MG from lumen to bath was 88 +/- 10 mumol.h-1.g-1 at 19 days
and 160 +/- 16 mumol.h-1.g-1 at 20 days. Bath-to-lumen flux was -17 +/- 2
mumol.h-1.g-1 and did not vary with age. Active, rapidly developing
transport of glucose and 3-O-MG is demonstrated by in vitro luminal
perfusion of the fetal rat ileum at 19 days.
