Effects of prostaglandins on peripheral nociceptors in acute inflammation

The effects of different prostaglandins were determined on (a) the hyperalgesia produced by subplantar injections of yeast given into the hind paws of weanling rats, and (b) the reflex vasopressor responses to bradykinin (BK) injected dose-arterially into the spleen of anaesthetised cats and dogs. In the rat prostaglandins (E1 greater than E2 greater than F2 alpha = F2 beta=A2=D2=I2O) injected into the same paw either with the yeast or 25 min later reduced the latency to the onset of hyperalgesia. In the cat and dog prostaglandins (E1 greater than E2 greater than F2 alpha greater than or equal to F2 beta greater than A1=A2=O) potentiated vasopressor responses to BK and reversed the inhibition of BK responses by indomethacin. It is likely that prostaglandins sensitize peripheral nociceptors through a specific prostaglandin receptor.