Abstract
Influences of diazepam, a benzodiazepine derivative, on the contractile response to calcium in skinned trabecular fibers of guinea pig heart were examined. Diazepam (100 μM) enhanced the contractile response of the skinned fiber to calcium and shifted the concentration-response curve to the left. The pCa50 values were 6.07±0.03 and 6.28±0.03 (P<0.05) in the absence and presence of diazepam, respectively. This result suggests that diazepam increases calcium sensitivity of contractile proteins in heart muscles.
