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

¹ Department of Medicine, Harvard Medical School, and Medical Services (Gastrointestinal Unit), Massachusetts General Hospital, Boston, Massachusetts

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 formation. 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--glycerophosphate is associated with a stimulus for glucose metabolism. However the stimulation of glucose metabolism is in excess of that required for L--glycerophosphate formation. The reasons for this are not clear at present. The effects observed with monoglycerides suggest predominant esterification with tissue free fatty acids by monoglyceride acylase in preference to hydrolysis intracellularly by monoglyceride lipase.

Key Words: intestinal fat absorption • fatty acids • monoglycerides • intestinal glucose metabolism • fatty acid esterification • hamster intestinal slices • monoglyceride esterification

Submitted on June 30, 1964