Effect of lipid absorption on glucose metabolism by slices of hamster small intestine

Abstract

Glucose utilization in vitro by hamster jejunal slices was shown to be enhanced during the absorption of free fatty acids and this effect was most striking with oleic acid. Glucose-C14 conversion to glyceride-glycerol was proportional to lipid concentration but, in addition, there was distinct increase in glucose oxidation and lactic acid-C14 formatioa in striking contrast to the effects of fatty acids, monoglyceride absorption was associated with little change in glucose utilization, and there was actually a reduction in glucose-C14 appearance in glyceride-glycerol. The data suggest that absorption of free fatty acids and their esterification with L-[alpha]-glycerophosphate is associated with a stimulus for glucose metabolism. However the stimulation of glucose metabolism is in excess of that required for L-[alpha]-glycerophosphate formation. The reasons for this are not clear at present. The effects observed with monoglycerides suggest predominant esteriflcation with tissue free fatty acids by monoglyceride acylase in preference to hydrolysis intracellularly by monoglyceride lipase.