ROLE OF VITAMIN-D-3 ON THE ACTIVITY PATTERNS OF HEPATIC DRUG-METABOLIZING-ENZYMES IN TRANSPLANTABLE MURINE LYMPHOMA

Vitamin D-3 (D-3) has been found to exert varied pharmacological actio ns including restriction of cell growth of a number of malignant cell fines in vitro and inhibition of the promotion of chemical carcinogene sis in mouse skin. In an attempt to confirm the efficacy of D-3 as an antineoplastic agent, the present investigation aims at characterizing the importance of D-3 in modulating hepatic drug metabolizing enzymes , namely, cytosolic glutathione S-transferase (GSHT) microsomal UDP gl ucuronyl transferase (UDPGT), and cytochrome P-450, which have been re ported by us in recent literature as significant neoplastic markers in mice bearing Dalton's lymphoma (DL). Results show that D-3 causes a 1 50% elevation of GSHT activity and the maintenance of normal, near-con trol UDPGT activity and cytochrome P-450 content, up to almost 30 days following tumor transplantation, along with bringing about a twofold increase in survival of the host mice. In conclusion, we confirm the d efinite and significant antitumorigenic role of D-3 and its involvemen t with the discussed hepatic tumor markers rn monitoring the processes that lead to cell survival.