Studies on peripheral actions of isatin.

ABSTRACT

The possible peripheral actions of isatin were studied in vivo and in vitro preparations in different experimental models, using conventional techniques. The results showed spasmogenic responses of isatin on guinea pig, rat and rabbit ileum and fundus of rat stomach. Histamine induced broncho-constriction could be antagonised by isatin. Isatin had cardioinhibitory effect on isolated frog heart and had hypotensive and respiratory depressant activities in dog. Isatin had antidiuretic effect. It was devoid of any effect on inflammation and gastric activities. The present results suggest a possible involvement of heterogenic 5-HT3 receptors in gastrointestinal smooth muscle.