Abstract
A clearing factor inhibitor (IM) was apparently produced by the pituitary and induced hyperlipemia in animals primed for lipid mobilization. Intravenous injection of toxic doses of protamine sulfate, convulsant doses of diisopropylfluorophosphate (DFP) and pyrogenic doses of piromen produced hyperlipemia in intact animals. The same doses of these substances injected into adrenal-ectomized and hypophysectomized rats did not produce hyperlipemia. The hyperlipemic action of protamine or DFP was not attributable to direct inhibition of lipoprotein lipase but to a secondary effect mediated through the adrenals and pituitary. The hyperlipemic action of protamine, DFP, pyrogens and possibly other stressors was best explained by release of IM.