Platelet aggregability in microvascular haemostasis and the effect of local inflammation.

The effects on haemostatic plug formation and individual vessel platelet aggregability of granulocytopenia, prostaglandin E1 (PGE1) and indomethacin were studied in microvessels of the rabbit mesentery. Granulocytopenia was found to have no effect. Indomethacin abolished the differences between arterioles and venules in haemostatic plug formation time and stability as well as individual vessel platelet aggregability. PGE1 significantly inhibited haemostasis and also counteracted indomethacine. It is concluded that the haemostatic differences normally seen between arterioles and venules can be explained by prostaglandin-induced inhibition of venular platelets.