THIOGLYCOLATE STIMULUS MODIFIES LYMPHOCYTE METABOLISM AND PROLIFERATION - A COMPARISON WITH LYMPHOCYTE-ACTIVATION BY WALKER-256 TUMOR IMPLANTATION

Key enzyme activities of glycolysis, the pentose-phosphate pathway, th e Krebs' cycle and glutaminolysis were measured in lymphocytes obtaine d from the control (CC), thioglycollate-injected (TC) and Walker 256 t umour-implanted (WT) groups, non-immune and immune inflammatory stimul i, respectively. The rates of incorporation of [2- C-14]-thymidine and [5-H-3]-uridine into cultured lymphocytes were also determined. The r esults indicated that the rates of both [2-C-14]-thymidine and [5-H-3] -uridine incorporation were enhanced in lymphocytes obtained from thio glycollate-injected (by an average of 80 per cent) and tumour-implante d animals (by 2.4-fold) as compared to control rats. Lymphocyte hexoki nase activity diminished both in the TG (23 per cent) and WT (61 per c ent) groups, whereas glucose 6-phosphate dehydrogenase activity was no t altered due to the non-immune inflammatory stimulus, being reduced ( 23 per cent) in WT rats as compared to CC. The activity of lymphocyte citrate synthase was lowered by thioglycollate (39 per cent) and tumou r-implantation (46 per cent). In contrast, glutaminase activity was au gmented in lymphocytes from the TG (41 per cent) and was not modified in the WT groups. Taken as a whole, the presence of the Walker 256 tum our did not affect the capacity for glutamine utilization but depresse d glucose metabolism in these cells. On the other hand, the non-immune inflammatory stimulus suppressed the activities of glycolysis and the Krebs' cycle and enhanced that of glutaminolysis in lymphocytes.