A COMPARISON OF THE BIOLOGICAL ACTIVITIES OF FOUR PROSTAGLANDINS

Abstract
The biological activities of prostaglandins E1, E2, E3 and F have been compared. Prostaglandins E1, E2 and E3 were qualitatively similar; E1 and E2 were about equiactive, but E3 was less active on all preparations. Prostaglandin F was a less potent vasodilator than E1 on the cat gastrocnemius muscle blood flow and skin blood flow and a less potent depressor drug on rabbit blood pressure. On the rabbit isolated jejunum F was twice as active as E1 but on the guinea-pig isolated ileum E1 was about forty times more active than F. One qualitative difference between these prostaglandins was observed; on the rabbit fallopian tube in vivo prostaglandins of the E series decreased both the tone and the peristalsis of the tube whereas prostaglandin F increased tubal tone.