Ageing erythrocytes and alloxan diabetes: II. Role of thyroxine in reversing diabetic state.

: The erythrocytes from control (C), diabetic (D) and thyroxine-treated diabetic (D+T4) rats were separated into three ageing groups (TAG) like light dense (young cells), intermediate-dense (middle-aged cells) and heavy-dense (old aged cells). Thyroxine reversed the diabetic defense enzymes to normal values like catalase in young cells, glutathione-s-transferase in middle-aged and old cells and levels of GSH in middle-aged cells. Thyroxine also increased the levels of GSSG in TAG whereas the levels of GSH increased in young cells, and decreased in old cells. The percentage of glycosylated haemoglobin did not return to normal levels by thyroxine in diabetic animals. Thyroxine may be playing the dual role in increasing the sulfhydryl levels and also inactivating enzymes in ageing erythrocytes of diabetic animals.