Effect of taurine on changes of nuclear and cytosolic ［Ca2+］ elicited by H2O2 in rat vascular smooth muscle cells / 中国药理学通报

ABSTRACT

AIM　As one of the reactive oxygen species, toxic dose of H2O2 leads to the necrosis or apoptosis of many kinds of cells. It is nuclear whether these processes are related with the changes of nuclear Ca2+ elicited by H2O2. This study on the effect of taurine on changes of nuclear and cytosolic (Ca2+) elicited by H2O2 in rat vascular smooth muscle cells. METHODS　The techniques of Fluo-3 and laser scanning confocal microscopy were used. RESULTS　Rapid and sustaining rise of nuclear ［Ca2+］ (［Ca2+］n) and cytosolic ［Ca2+］(［Ca2+］c) were found in cultured rat vascular smooth muscle cells upon adding of 0.5% H2O2. Pretreatment of the cells with 20 mmol*L-1 taurine, a regulator of cellular Ca2+ homestasis, significantly decreased the rise amplitude of ［Ca2+］n (P<0.05), but failed to affect that of ［Ca2+］c (P>0.05) elicited by H2O2. It was suggested that the changes of ［Ca2+］n and ［Ca2+］c have different respond to taurine. CONCLUSION　It was concluded that there exist the independent regulating mechanisms of Ca2+ in the nucleus from differences between the nucleus and cytosol Ca2+ in sensitivity to action of H2O2 and taurine.