Experiments were carried out to determine whether changes in endogenous heparin in rat tissues were related to changes in plasma levels of clearing factor lipase (CFL). Skin heparin levels, postheparin plasma CFL levels, and peritoneal mast cell counts were measured in normal, adrenalectomized, cortisone-treated, and X-irradiated rats. Total body X-irradiation in doses of 400 r to 600 r decreased skin heparin levels. The postheparin CFL levels of irradiated rats remained high while that of pair-fed controls dropped significantly. Cortisone treatment for 6 days caused an increase in plasma CFL levels in both intact and adrenalectomized rats but no significant change in skin heparin levels or mast cell count. Adrenalectomy caused no significant change in either postheparin CFL or skin heparin levels.
INHIBITION OF URETHAN LUNG TUMOR INDUCTION IN MICE BY TOTAL-BODY X IRRADIATION