[Excitant effect of suberogorgin on isolated guinea pig trachea]

Suberogorgin (Sub) was shown to increase the tension of isolated guinea pig trachea in a dose-dependent manner. Its ED50 was 52.5 mumol.L-1. The stimulation of sub on trachea was antagonized by atropine 0.65 mumol.L-1, and inhibited by atropine 0.13 mumol.L-1, cobrotoxin 2.4 micrograms.ml-1 and by tetrodotoxin 1 mumol.L-1. On the contracted trachea induced by galanthamine 35.5 mumol.L-1, acetylcholine increased the tension but Sub did not. Galanthamine was also shown not to increase the tension of trachea that had been treated with Sub 258 mumol.L-1 for 10 min. The results indicate that the trachea-excitant action of Sub is related to the M and N receptor and the Na+ channel.