THE ROLE OF THE MUCOSA IN THE IN-VITRO CHANGES IN GUINEA-PIG BLADDER FUNCTION WHICH OCCUR AFTER SENSITIZATION WITH OVALBUMIN

Bladder strips from sensitized guinea pigs respond to ovalbumin challe nge with a contraction accompanied by release of histamine, prostaglan din, and leukotriene. Histamine and prostaglandin release occurs prefe rentially from the bladder mucosa, while leukotrienes are released by the smooth muscle. This study investigated the effects of removal of t he bladder mucosa on contractile responses of strips from control and sensitized guinea pigs to electrical stimulation and to contractile ag onists. Removal of the mucosa potentiated the contractile response to electrical stimulation at low voltages and pulse durations. The presen ce of ovalbumin had no effects on the response to electrical stimulati on. Removal of the mucosa had no effect on the contractile responses o f bladder strips to bethanechol, histamine, KCl, or ovalbumin, althoug h after correction for the decreased strip mass after mucosa removal t here was a tendency for the responses to increase. We conclude that th e responsiveness of bladder strips from sensitized guinea pigs to oval bumin challenge results primarily from effects which occur within the smooth muscle.