[Insulin receptors in diabetes mellitus]

We described the clinical significance of the measurement of insulin receptors and the mechanism of non-insulin dependent diabetes mellitus (NIDDM). Changes in insulin receptor (IR) of red blood cells in 47 patients with NIDDM were compared with those of 28 normal controls. The levels of high and low-affinity IR in the 47 patients with NIDDM were lower than those of normal controls and were prominent in untreated new NIDDM patients. Hyperinsulinemia was not found in these patients, indicating that the low IR is a primary defect not caused by the "down regulation" mechanism. In the IDDM patients the levels of high and low-affinity IR were higher than those of the normal controls, but decreased markedly after insulin therapy, indicating that the "up regulation" is attributable to the high IR levels, other than the primary IR defect.