Lipoprotein lipase activity in adipose tissue and skeletal muscle of human diabetics during insulin deprivation and restoration

Twelve insulin-dependent diabetic patients were deprived of insulin for 12 h, and thereafter given an 8-h i.v. infusion of insulin. Lipoprotein lipase (LPL) activity was determined from heparin eluates of adipose tissue and skeletal muscle before and after insulin infusion. In spite of development of marked hyperglycemia and hyperketonaemia during the insulin deprivation the LPL activity of the two tissues remained mostly within normal range. During the subsequent insulin administration the LPL activity of adipose tissue increased by 36% (p less than 0.05) whereas the skeletal muscle LPL remained unchanged. The result is compatible with the view that human adipose tissue LPL is more sensitive to insulin than the corresponding enzyme of muscle.