CHARACTERIZATION OF RAT LYMPHOCYTE PRIMARY CULTURE FOR THE DEVELOPMENT OF AN IN-VITRO MUTAGENESIS ASSAY - EFFECT OF INTERLEUKIN-2 AND 2-MERCAPTOETHANOL ON THE ACTIVITIES OF INTERMEDIARY METABOLISM ENZYMES AND CELL-PROLIFERATION

Efficient energy utilization is essential for cell growth; in an attem pt to improve the growth conditions of the rat T-lymphocyte culture mo del for potential use in studying the mutagenic activity of carcinogen s in vitro, we have investigated the effects of phytohemagglutinin (PH A), interleukin-2 (IL-2) and 2-mercaptoethanol (2-ME) on the activitie s of intermediary metabolism enzymes and cell proliferation. Isolated lymphocytes were cultured in the presence and absence of PHA, IL-2, or 2-ME. The intermediary metabolism enzymes investigated were glutamate dehydrogenase, glutamate-pyruvate transaminase, malate dehydrogenase, isocitrate dehydrogenase, lactate dehydrogenase, pyruvate kinase, and fatty acid synthetase (FAS). Measurable activity of all enzymes inves tigated, except for FAS, was detected in PHA-stimulated cells cultured with IL-2 or 2-ME. The unstimulated lymphocytes had significantly low er enzyme activity than stimulated cells. The combination of all three agents showed increased enzyme activity. This increase in activity br ought about by the combination of the three agents was not reproduced by either agent acting alone. In general, the increase in enzyme activ ity correlated with cell proliferation as measured by [H-3]thymidine u ptake in PHA-stimulated cultures containing IL-2 and/or 2-ME. The resu lts suggest that the addition of exogenous IL-2 and 2-ME enhances meta bolic function and may be beneficial in in vitro culture of rat lympho cytes.