INSULIN-TREATMENT CAN ABOLISH CHANGES IN GLUCOSE AND GLUTAMINE-METABOLISM OF LYMPHOCYTES AND MACROPHAGES CAUSED BY THE IMPLANTATION OF THE WALKER-256 TUMOR

Activation of lymphocytes and macrophages by the implantation of tumou r cells (10(7) cells per rat) into the left flank of rats increased th e conversion of glucose to lactate and of glutamine to glutamate and a spartate and the decarboxylation of [U-C-14]-glucose and [U-C-14]-glut amine in incubated cells. In addition, the amount of GLUT1 was increas ed in macrophages. The effect of insulin treatment on glucose and glut amine metabolism of lymphocytes and macrophages activated by Walker 25 6 tumour implantation was also examined. For this purpose, insulin was injected subcutaneously (4 U/100 g b.w. daily) after the fourth day o f tumour implantation and the rats were killed 10 days afterwards. Ins ulin treatment fully reverted the changes due to tumour implantation i n the metabolism of glucose and glutamine in lymphocytes and of glucos e in macrophages.