Influence of glucose, insulin and sera from diabetic patients on the prostacyclin synthesis in vitro in cultured human endothelial cells.

The effects of glucose, insulin and sera from Type 1 (insulin-dependent) diabetic patients on the synthesis of prostacyclin in vitro were studied in confluent primary cultures of human endothelial cells. The stable metabolite, 6-keto-prostaglandin F1 alpha, was measured in growth medium after 24 h of incubation with endothelial cells in a buffer incubated with the cells for 10 min on a rocker platform, and in a buffer solution of ruptured cells. Glucose (11, 15, 20 or 25 mmol/l) and glucose (11 mmol/l) plus insulin (10(3), 10(4) or 10(6) mU/l) in growth medium did not have any effects on the prostacyclin synthesis. The prostacyclin synthesis was significantly reduced in cell cultures incubated with medium supplemented with 10% serum from patients with Type 1 diabetes (p less than 0.01) compared with cultures incubated with pooled serum from healthy blood donors. These data suggest that diabetic sera inhibit the prostacyclin synthesis in cultured endothelial cells unrelated to the glucose and insulin levels.