Gastrointestinal activities of a new pirenzepine-analog, nuvenzepine, in the cat

Nuvenzepine, a new pirenzepine-analog, administered intraduodenally, displayed a long-lasting and dose-dependent inhibition of neostigmine-induced intestinal motility in anaesthetized cats. On ileal motor activity, the compound showed a potency 10 times greater than that of pirenzepine, and, although to a lesser extent, it was also active, unlike pirenzepine, on colonic stimulated motility. Furthermore, in conscious cats, nuvenzepine inhibited pentagastrin-stimulated gastric acid secretion resulting 25-30 times more potent than pirenzepine. The observed differences between antisecretory and antispastic activities displayed by nuvenzepine and pirenzepine suggest that the new pirenzepine-analog may act on gastrointestinal functions through an additional non-anticholinergic mechanism.