Vorticella-a model for chemopharmacodynamic action on smooth muscle

1. 1. Vorticella contracture is a unique model for studying non-specific chemical stimulus (chemopharmacodynamic action). 2. 2. The classic agonists have no activity up to 1 mM, except for low sensitivity towards nicotine. We could not find evidence for the presence of the adenyl cyclase or the prostaglandin systems. 3. 3. On the other hand, the usual non-specific stimulators are active. They include oxidizing agents with low redox potential, such as phenazine methosulphate or menadione; glutatione oxidizing agents, such as diamide, KCN, N-tert.-butyl-5-methylisoxazolium. Papaverine is inhibitory, whereas ouabain has no effect on the phenazine methosulphate-induced contractures.