The effect of Synacthen administration on lipoprotein lipase activity in the epididymal fat pad of the rat.

Conflicting data have been reported on the influence of (excess) glucocorticoids on lipoprotein lipase (LPL) activity in adipose tissue. To solve this problem hypercorticism was induced in rats by treatment for varying periods with Synacthen, a synthetic corticotrophin-1-24 preparation, and LPL was measured in the epididymal fat pads using different methods. In extracts of defatted tissue preparations from overnight fasted rats treated for 3 days with Synacthen we observed an increase in LPL activity (acetone-ether powder LPL) to values similar to those found in normally fed controls. In contrast, the heparin-elutable part of LPL activity in the tissue was not influenced by the Synacthen treatment. This activity remained significantly lower in overnight fasted animals, Synacthen treated or not, than in normally fed rats. Adrenalectomy lowered the acetone-ether powder LPL activity of the epididymal adipose tissue in fasted as well as in fed rats. In fasted rats it prevented the stimulation of the LPL activity by Synacthen.