Plasminogen activator inhibitor-1 (PAI-1), a product of endothelial cells, is a regulator of fibrinolysis and a modulator of extracellular matrix proteolysis. Presently, we investigated PAI-1 expression in retinal capillaries of monkeys with noninsulin dependent diabetes mellitus (NIDDM) compared to nondiabetic controls. Colloidal gold immunocytochemistry was used to quantify PAI-1 antigen in retinas from diabetic (n=10) and nondiabetic (n=ll) rhesus monkeys. PAI-1 immunoreactivity was significantly increased (PO.001) in retinal capillaries of diabetic monkeys (3.6 fold over nondiabetic controls). In the diabetic monkeys, PAI-1 was seen in the capillary lumen, within the cytoplasm of endothelial cells and in the basement membrane. Minimal PAI-1 was detected in retinas of nondiabetic monkeys. PAI-1 levels correlated with basement membrane thickness in the diabetic monkeys (P0.001). These studies suggest that PAI-1 is overexpressed in retinal capillaries of monkeys with NIDDM. By decreasing extracellular proteolysis, PAI-1 overexpression may contribute to basement membrane thickening observed in diabetic retinopathy.
|Original language||English (US)|
|Number of pages||1|
|Journal||Fibrinolysis and Proteolysis|
|Issue number||SUPPL. 3|
|State||Published - Dec 1 1997|
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