[The anti-arrhythmia activity of isoteolin (IST)].

The antiarrhythmic activity of IST was studied on some experimental models of cardiac arrhythmia--caused by adrenaline in rats, caused by barium in non-narcotized rabbits, caused by strophanthin in guinea pigs, caused by aconitine and calcium in rats. Rhythmic disturbances were recorded by a 12-channel polyphysiograph "Galileo" or a single-channel electrocardiograph "Cardiomat". The obtained results showed that IST manifested antiarrhythmic activity in respect to adrenaline, barium and strophanthin arrhythmias without affecting substantially aconitine and calcium arrhythmias.

[The effects of isotheoline (IST) on the nonvascular smooth musculature].

The influence of IZT on nonvascular smooth musculature in experiments in vitro was studied: on isolated intestine of the rabbit, ileum of the guinea pig, an uterine horn of the rat and guinea pig, vas deferens of the rat; as well as in vivo: on an experimental model of bronchospasm of guinea pigs, induced by acetylcholine, histamine and serotonin. Isometric contractions were recorded, and in the experiments in vivo--the tonus of the bronchial smooth musculature by a piston recorder. The obtained results showed that in experiments in vitro IZT increased the dose dependent tonus of intestinal smooth musculature; inhibited predominantly at low concentrations like clonidine the contractions of vas deferens of the rat by low frequent field stimulation--0.