[Pharmacological actions of alkylaminoalkyl-phenylbenzisothazole compounds on the gastrointestinal tract].

In the present paper pharmacological properties studied on the gastrointestinal tract of two new alkylaminoalkylphenylbenzisothiazole derivatives, 4-dimethylamino-2-phenyl-2-(1,2-benzisothiazole-3-yl)butyramide (PM2) and N,N-dimethyl-3-phenyl-3-(1,2-benzisothiazole-3-yl)propylamine (PM3) have been reported. Both drugs showed antispasmodic effects on gastroduodenal junction of the anaesthetized rat stimulated by Caerulein, according to previous results obtained on guinea-pig isolated ileum. On this substrate they were different in the potency being PM3 more active than PM2. On the contrary, the hypersecretion induced by Histamine or Gastrin-17 in rat perfused stomach was potentiated by PM2 and inhibited by PM3. Similar effects were observed on guinea-pig "in vitro" stomach preparation where PM2 and Papaverine were ineffective in modifying Histamine dose-response curves and PM3 reduced significantly maximal peak effects of Histamine, behaving as a non-competitive antagonist. The significant differences observed on gastric secretion but not on other substrates, from compounds structural analysis, appear scarcely justified and seem to us important to be further investigated.