FURTHER STUDIES ON THE ENDOCRINE CONDITIONING OF THE HEPARIN-INDUCED LIPEMIA CLEARING ACTIVITY (LCA) IN THE RAT

Abstract

The effects of various endocrines and of stress on the "lipemia clearing activity" (LCA) which is elicited in rat plasma by intravenous heparin injection were studied.High dosage cortisone accelerated LCA, but low dosage cortisone did not affect it. Severe catabolic stress accelerated LCA. Application of a single mild stress was ineffective, but the combination of two mild stressors accelerated LCA. ACTH had no influence on LCA, but adrenalectomy accelerated it. Stilbestrol inhibited LCA at both a low and a high dosage level, but there was no difference in LCA production between males and females or between estrous and diestrous females. Estrous females, however, displayed less LCA than ovariectomized females. Anterior pituitary extract inhibited LCA in females and hypophysectomy accelerated it in both sexes. A synthetic oil emulsion yielded the same qualitative information as lipemic plasma wherever it was used as a substrate for the clearing activity of postheparin plasma.Thus, with the exception of the effects of sex difference and low dosage cortisone, most of the previously reported endocrine effects on the LCA that follows subcutaneous heparin were also obtained when heparin was injected intravenously. The physiological significance of these findings is discussed.