HIGH PLASMA INTERLEUKIN-2 - A POTENTIAL CAUSE OF INSULIN-RESISTANCE

Low-density lipoproteins, infections and smoking are closely associate d with insulin resistance. According to the hypothesis proposed in thi s paper, all of these factors could cause insulin resistance by the sa me mechanism. The first step in the cascade of events leading to insul in resistance is increased production of interleukin-2. This is follow ed by secretion of other cytokines, activation of macrophages and incr eased production of nitric oxide from L-arginine. The reduced amount o f plasma L-arginine leads to decreased secretion of growth hormone and insulinlike growth factor-1 during exercise. The decreased secretion of insulinlike growth factor-1 is the basic reason for insulin resista nce. Tumour necrotizing factor may also be involved in the pathogenesi s of insulin resistance directly by binding in beta-adrenergic recepto rs. High plasma interleukin-2 also causes decreased bioavailability of insulinlike growth factor-1 by reducing the production of androgenic hormones.