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Updated: Aug 14, 2026

Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology
Published on: August 18, 2014
Changes in duodenal contractility induced by "calcium antagonists" with different modes of action
Abstract:
The inhibitory action of nifedipine, verapamil, diltiazem and trifluoperazine has been examined on isolated duodenum from rats and rabbits. On rabbit duodenum Ca2+ antagonists caused a reduction of the spontaneous motility in very low concentrations (10(-12)-10(-6)M). On rat duodenum Ca2+ antagonists inhibited the contractile response to BaCl2, CaCl2 and to field stimulation, nifedipine being the most potent compound (threshold concentration down to 10(-12)M). The above results indicated that Ca2+ antagonists can markedly alter the duodenal motility, both basal and drug-stimulated. The high potency of nifedipine and the selective antagonism by Bay K 8644 against nifedipine suggest the presence of a specific receptor for the dihydropyridines (DHP receptor) in the duodenum.
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