NO MEASURABLE EFFECT OF AMYLIN ON LIPOLYSIS IN EITHER WHITE OR BROWN ISOLATED ADIPOCYTES FROM RATS

Amylin, a 37-amino acid pancreatic beta-cell hormone which has potent effects on skeletal muscle glycogen metabolism, has no demonstrable effect on white adipocyte carbohydrate oxidation or insulin stimulated incorporation of glucose into triacylglycerol. We have now determined amylin's effects on lipolysis in both white and brown adipocytes, by measuring extracellular release of glycerol in normal rats. Amylin (10(-13)M to 10(-6)M) did not alter basal or norepinephrine (10(-6)M, 10(-7)M)-stimulated lipolysis. Additionally when insulin (10(-8)M, 10(-9)M) was used in combination with norepinephrine, the antilipolytic effect of insulin was not altered by amylin, Thus, amylin did not affect basal or stimulated lipolysis in the presence or absence of insulin. It therefore appears that amylin would preferentially induce insulin resistance in muscle while sparing fat.