ABSORPTIVE CAPACITY AND INTESTINAL MOTILITY IN UNANÆSTHETIZED RATS DURING INTRADUODENAL INFUSION OF FAT

Abstract

Emulsified coconut oil mixed with unabsorbable, water soluble reference material, polyethylene glycol(PEG) was given to unanæsthetized rats in restraint cages. Complications due to variable stomach emptying were evaded by steady infusion through previously implanted duodenal cannulæ. Recoveries of fat in rats killed after 2‐hr. and 4‐hr. infusions showed a steady rate of absorption with a capacity limited to about 100 mg. coconut oil per hr. Recoveries of PEG showed an increased rate of propulsion, particularly through the distal small intestine, in the presence of either coconut or cottonseed oil. Fat: PEG ratios in proximal and distal halves of the small intestine were consistent with predominantly distal absorption of fat until absorptive capacity was nearly saturated, when there was evidence that the reference substance moved ahead of the fat.