Open AccessDiazepam Increases Calcium Sensitivity of the Skinned Cardiac Muscle Fiber in Guinea Pig.
Author(s) -
Yukio Hara,
Akihito Chugun,
Keisuke Futamura,
Tokuzo Nishino,
Hiroshi Kondo
Publication year - 1999
Publication title -
japanese journal of pharmacology/japanese journal of pharmacology
Language(s) - English
Resource type - Journals
eISSN - 1347-3506
pISSN - 0021-5198
DOI - 10.1254/jjp.81.122
Subject(s) - diazepam , calcium , guinea pig , chemistry , medicine , endocrinology , papillary muscle , benzodiazepine , biophysics , pharmacology , biology , receptor
Influences of diazepam, a benzodiazepine derivative, on the contractile response to calcium in skinned trabecular fibers of guinea pig heart were examined. Diazepam (100 microM) 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.