Abstract
Urchi-toxins (crude Urchi-toxin F2 and Urchi-toxins F3, F4 and F5) derived from Toxopneustes pileolus were investigated physicochemically and pharmacologically. F22 was found to be a mixture of several substances (F3, F4 and F5) being basic peptides or proteins. F2 and F3 inhibited strongly and slightly the cardiac movement of experimental animals, respectively, while F4 and F5 rather stimulated the heart beat. F2 and F3 elicited remarkable contraction of the small intestine. F2, F3 and F5 stimulated contraction of the uterus. Actions of F2 on smooth muscles were inactivated by chymotrypsin.
