Cisplatin-mediated enzymatic changes in mice bearing ascites Dalton's lymphoma

We have assayed the activities of nine enzymes in one or more tissues of no rmal, tumour (Dalton's lymphoma) bearing and cisplatin-treated tumourous mi ce. In the liver of tumour-bearing hosts glucose-6-phosphatase and arginase activities decreased significantly while LDH activity increased significan tly, as compared to normal mice. Cisplatin treatment for 24, 48, 72 and 96 h produced a significant rise in liver glucose-6-phosphatase and significan t fall in LDH activity. LDH activity declined significantly in DL cells but increased significantly in ascites supernatants following cisplatin treatm ent which may suggest the leakage/release of LDH from the DL cells. The ser um and ascites supernatant glucose levels increased significantly following cisplatin treatment. Arginase activity rose significantly from 8 to 48 h o f cisplatin treatment but fell later at 96 h. The raised activity of cathep sin B and H in the ascites supernatants and sera after cisplatin treatment may suggest their secretion in the fluids from different tissues and may al so contribute to the tumouricidal effect mediated by cisplatin. As compared to normal animals serum GOT and GPT activities were significantly higher i n tumour-bearing hosts. Cisplatin treatment led to a significant increase i n GOT activity in ascites supernatants. Activities of membrane enzymes, (Na + + K+) Mg2+-ATPase as well as 5'-nucleotidase, gradually declined in the t umour cells, with concomitant rises in ascites supernatants, following cisp latin treatment. The lower activities could be due to loss from the cells o r some other mechanism and may also add indirectly to the antitumour activi ty of cisplatin. As compared to normal mice, the total protein concentratio n in the kidney of tumour-bearing hosts decreased significantly but increas ed significantly in serum. Cisplatin treatment resulted in significant decr eases in protein concentration in kidney, serum and DL cells. It is suggest ed that these enzymatic changes may affect the metabolism of tumour cells a nd other tissues, perhaps facilitating the anticancer activity of cisplatin . Med Sci Res 27:723-730 (C) 1999 Lippincott Williams & Wilkins.