The Effect of Lymphoma and Other Neoplasms on Hepatic and Plasma Enzymes of the Host Rat1

gen , a-fetoprotein , on -y-glutamyl tnanspeptidase activities exemplify useful, although not entirely specific, indicators of intestinal cancer (1, 4, 5, 26, 31). Most other serum enzymes [e.g., alkaline phosphatase (2), galactosyltransfen ase (24), and ornithine transcarbamylase (25)] and proteins usually tested provide less clear-cut distinctions and may not even be unique to the disease of cancer. The purpose of the present study was to test for correlations between en zymic changes in liven on plasma and the kind of neoplasm thatwas implantedintotherats. Earlier studies from this laboratory (11) on the systemic effects of transplanted mammary tumors showed that the enzymic composition of the host liven becomes partially undifferentiated, resembling that of normal immature liven or well-differentiated hepatomas. The liver and plasma sam pIes now examined were derived from hosts with tumors of hepatic, lymphoid, renal, submaxillary, and mammary gland origin. Nine enzymes (chosen for reasons to be dis cussed later) were quantified in liver (and in the tumors), and 2 were quantified in plasma. A partial biochemical immaturity was apparent in host livers in general. However, particular aspects of the host response were characteristic for the type of tumor that evoked them . Analyses of several hepatic enzymes could distinguish rats beaning mammary on submaxillary gland tumors from those with a hepatoma, lymphoma, or a slow-growing renal tumor. The most striking findings were those on lymphoma-bean ing rats. The presence of pynroline-5-canboxylate neductase (EC 1.5.1 .2) and of thymidine kinase (EC 2.7.1 .75) in plasma was unique to hosts of this tumor, as was the rapidity (4 days after transplantation) of the rise in hepatic thymidine kinase and the diminution of hepatic arginase (EC 3.5.3.1). Additional studies involving cortisol treatment, histological examinations, enzymic analyses of blood cells, and thymus were carried out in order to seek an explanation for the host responses that were specific for the lymphoma.