Effects of flurazepam and diazepam in isolated guinea-pig taenia coli and longitudinal muscle.

The effects of the benzodiazepine derivatives flurazepam and diazepam on K+- and Ca2+ -induced contracture were examined in isolated taenia coli and longitudinal muscle of the guinea-pig. Flurazepam and diazepam inhibited the tonic component more than the phasic component of the K+ -induced contracture of taenia coli. In longitudinal muscle, both flurazepam and diazepam inhibited the Ca2+ -induced contracture dose-dependently. These findings suggest that the observed effects of flurazepam and diazepam may have been due to inhibition of the transmembrane influx of Ca2+.