Effect of E-type prostaglandins on bradykinin-induced plasma extravasation in the knee joint of the rat.
We studied the effect of different E-type prostaglandins on an experimental model of inflammation in the rat. Plasma extravasation was induced in the knee joint of the rat by continuous perfusion of two potent inflammatory mediators, bradykinin (160 nM) or platelet activating factor. Both prostaglandin E1 and prostaglandin E2 (0.5-500 ng ml-1), when perfused with bradykinin, produced a similar dose-dependent enhancement of plasma extravasation. Prostaglandin E2 (0.5-500 ng ml-1) also dose dependently enhanced plasma extravasation induced by platelet activating factor, while prostaglandin E1 significantly enhanced platelet activating factor-induced plasma extravasation only at concentrations above 5 ng ml-1. In contrast, co-perfusion of bradykinin or platelet activating factor with the prostaglandin E1 analogues, enisoprost and misoprostol (0.5-500 ng ml-1) did not enhance plasma extravasation. In fact, misoprostol attenuated plasma extravasation induced by bradykinin. These results demonstrate that in the rat knee joint, misoprostol and enisoprost have different pharmacological actions compared to their parent compound, prostaglandin E1 and to prostaglandin E2.
Green
P G
PG
Department of Oral Surgery, University of California, San Francisco 94143.
Luo
J
J
Heller
P H
PH
Levine
J D
JD
D000818:Animals; D001169:Arthritis, Experimental / Q000139:chemically induced / Q000503:physiopathology*; D001920:Bradykinin; D002199:Capillary Permeability / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D007596:Joints / Q000503:physiopathology*; D008297:Male; D010972:Platelet Activating Factor; D011458:Prostaglandins E / Q000494:pharmacology*; D011459:Prostaglandins E, Synthetic / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D010972:Platelet Activating Factor; D011458:Prostaglandins E; D011459:Prostaglandins E, Synthetic; D001920:Bradykinin