Effect of Cisplatin on the Lactate Dehydrogenase Activity and its Isozyme Pattern in Dalton's Lymphoma Bearing Mice.

Abstract

Lactate dehydrogenase (LDH) activity and its isozyme patterns were determined in various tissues of normal, Dalton's lymphoma (DL) bearing and cisplatin treated tumorous mice. Tumorbearing hosts showed about two fold higher serum LDH activity than that in the normal animals and following cisplatin treatment (8 mg/kg body wt, i.p.) for 1-4. days, serum LDH activity further increased. In kidney, as compared to normal mice, there was no significant change in the enzyme activity in tumor bearing hosts, but liver LDH activity increased in tumorous condition. After cisplatin treatment overall 20-30% decrease in the activity was noted in kidney and liver, with slight increase on the day 2 of treatment. LDH isozyme analysis revealed that in serum and kidney, all the five isozyme constituents were present, whereas, in liver and ascites tumor supernatant only LDH-3, -4 and-5 were observed with the predominance of LDH-5. In liver, after cisplatin treatment LDH-3 and-4 expression gradually decreased. In DL cells, LDH-5 was the only isozyme form present and after cisplatin treatment its activity increased.Thus, it is suggested that LDH activity is definitely affected in the tissues of tumor bearing hosts and during tumor regression after cisplatin treatment. The changes in LDH activity could be very useful parameter in malignancy and cisplatin-mediated chemotherapy against murine Dalton's lymphoma in particular and cancer in general. LDH isozyme patterns revealed the presence of tissue specificity of different isozymes, with only LDH-5 in tumor cells and appearance of some specific isozyme variant, named here as LDH-T, in the serum of tumor bearing hosts.