Increase in circulating basement membrane antigens in diabetic rats and effects of insulin treatment

The serum concentrations of two recently discovered antigens derived from basement membranes (7-S collagen and laminin P2) were assayed in streptozotocin-diabetic rats as possible indicators of basement membrane metabolism. The concentrations of both increased significantly after 8 weeks of diabetes, and that of 7-S collagen at least remained elevated up to 24 weeks. Treatment with insulin, which did not correct the metabolic disturbances, inhibited the increase in the concentration of 7-S collagen in serum, but did not completely normalize that of laminin P2.