The pharmacological effects of some 1H-1,4-benzothiazineylide derivatives on the cardiovascular system of the rat and some smooth muscles.

A series of 1H-1,4-benzothiazineylides was synthesized and characterized. The influence of this series of compounds 1-7 was examined on the cardiovascular system of the rat, the isolated jejunum of the rabbit, the guinea-pig ileum and the isolated uteri of late pregnant rats. The results of the present study revealed the bradicardiogenic effect of the ethyl, propyl and isobutyl derivatives when tested in the dose range of (10-53 mumole Kg-1). Furthermore, the isobutyl derivative also exhibited an ability to decrease the arterial blood pressure. All the test compounds exhibited non-spasmolytic activity against ACh, histamine and BaCl2. The butyl, isobutyl and isopropyl derivatives were found to be the most potent. The results direct the attention to a new potential group of cardiovascular depressant and spasmolytic agents.