POSTPRANDIAL SERUM-LIPIDS AND TISSUE LIPOPROTEIN-LIPASE ARE ACUTELY ALTERED IN RATS BY THE ALPHA-GLUCOSIDASE INHIBITOR ACARBOSE

The purpose of this study was to evaluate the consequences of the acar bose-induced attenuation of postprandial glycemia and insulinemia on p lasma lipid concentrations and on tissue lipoprotein lipase (LPL) acti vity. Rats were fed a high-sucrose diet ad libitum for two weeks. On t he day of the experiment, half of the animals were given a high-sucros e meal, whereas the other half were given acarbose (10 mg/kg body weig ht) mixed with the meal. Serum lipids and tissue LPL activity were ass essed in samples collected one hour after meal intake. Glycemia was co mparable in both groups, whereas serum insulin in acarbose-fed rats wa s half that of control animals. The main effects of acarbose on postpr andial lipids consisted of a lowering of triacylglycerols (-50%) and n on-high density lipoprotein cholesterol. LPL was not altered by acarbo se in white and brown adipose tissues, but was higher in the heart (+3 3%). The effects of acarbose on postprandial serum lipids are consiste nt with a slower rate of de novo lipogenesis from carbohydrate precurs ors and a consequent lowering of very-low density lipoprotein secretio n into the circulation. In addition, the acarbose-induced dampening of the postprandial excursion of insulin may have maintained higher LPL activity in the heart, which would be liable to participate in the hyp otriacylglycerolemic action of the inhibitor.