@article{APS6790,
author = {Yan Huang and Zhen-He He and Yun-Xia Li},
title = {Effects of MCI-154 on calcium sensitivity of contractile system and calcium release from sarcoplasmic reticulum in saponin-skinned rat myocardium},
journal = {Acta Pharmacologica Sinica},
volume = {18},
number = {3},
year = {2016},
keywords = {},
abstract = {AIM: To explore the possible mechanisms underlying the positive inotropic effect
of MCI-154.
METHODS: Skinned fibers with disrupted or preserved sarcoplasmic reticulum (SR)
were prepared by saponin 500 or 50 mg.L-1. The tension-pCa relationship and pCa50
of saponin (500 mg.L-1)-skinned fibers were taken as the indices of Ca2+
sensitivity of contractile proteins. The amplitude of caffeine-induced
contracture was an index of Ca2+ release from SR in saponin (50 mg.L-1)-skinned
fibers.
RESULTS: 1) MCI-154 (0.1 mmol.L-1) showed a Ca2+ sensitizing effect on
contractile proteins. The pCa50 was increased to 5.84 (5.54-6.14) compared with
control value 5.54 (5.30-5.79) (P < 0.01, n = 8). Hill coefficient n was
decreased by 0.29 (P < 0.01, n = 8); 2) No contracture was produced by MCI-154 in
preparations with preserved SR. Caffeine-induced contracture before and after
MCI-154 treatment were not changed (P > 0.05, n = 4).
CONCLUSION: MCI-154 directly enhances the Ca2+ sensitivity of contractile protein
but has little effect on Ca2+ release from SR in rat skinned cardiac fibers.},
issn = {1745-7254}, url = {http://www.chinaphar.com/article/view/6790}
}