Thioglycollate stimulus modifies lymphocyte metabolism and proliferation. A comparison with lymphocyte activation by walker 256 tumour implantation

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Abstract
Key enzyme activities of glycolysis, the pentose‐phosphate pathway, the Krebs' cycle and glutaminolysis were measured in lymphocytes obtained from the control (CC), thioglycollate‐injected (TG) and Walker 256 tumour‐implanted (WT) groups, non‐immune and immune inflammatory stimuli, respectively. The rates of incorporation of [2‐14C]‐thymidine and [5‐3H]‐uridine into cultured lymphocytes were also determined. The results indicated that the rates of both [2‐14C]‐thymidine and [5‐3H]‐uridine incorporation were enhanced in lymphocytes obtained from thioglycollate‐injected (by an average of 80 per cent) and tumour‐implanted animals (by 2·4‐fold) as compared to control rats. Lymphocyte hexokinase activity diminished both in the TG (23 per cent) and WT (61 per cent) groups, whereas glucose 6‐phosphate dehydrogenase activity was not 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 tumour‐implantation (46 per cent). In contrast, glutaminase activity was augmented 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 tumour did not affect the capacity for glutamine utilization but depressed 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.