小檗碱对培养的新生大鼠心肌细胞内游离钙含量的影响

采用Ｃａ２＋指示剂Ｆｕｒａ－２作为细胞内钙离子的荧光探针，利用ＡＲ－ＣＭ－ＭＩＣ阳离子测定系统。检测了培养新生大鼠心肌细胞内游离钙的浓度，并观察了小檗碱对去甲肾上腺素，Ｈ２Ｏ２，高Ｃａ２＋及高Ｋ＋引起细胞内钙离子浓度（［Ｃａ２＋］ｉ）变化的影响。小檗碱对心肌细胞静息［Ｃａ２＋］ｉ无明显影响，能浓度依赖地抑制去甲肾上腺素和Ｈ２Ｏ２引起的［Ｃａ２＋］ｉ的升高。小檗碱５０μｍｏｌ·Ｌ－１能抑制高Ｋ＋引起的［Ｃａ２＋］ｉ的升高，而小剂量（１－１０μｍｏｌ·Ｌ－１）则无作用。对搏动细胞，小檗碱能抑制其［Ｃａ２＋］ｉ瞬间变化的最大值，对最小值则无作用。

Effect of berberine on cytosolic free Ca2 concentration in cultured myocardial cells of neonatal rat

Intracellular free calcium concentra-tion(Ca2+]i)was measured with ca2+ -sensitive fluor-escent indicator Fura-2/AM in cultured mvocardialeells of neonatal rats using AR-CM-MIC cationmeasurement system. Resting Ca2+]i was 83 ± 8nmol·L-1 in the presence of Ca2+ 1. 8 mmol·L-1in Hanks solution. Berberine had no effect on the rest-ing Ca2+]i,when the extracellular Ca2+ were 1.8-5.4mmol·L-1.Berberine 1-100 μmol·L-1 concentra-tion-dependently inhibited norepinephrine and H2O2induced Ca2+]i elevation. Berberine 50 μmol·L-1inhibited K+ induced Ca+]i elevation. Berberine10,30 μmol·L-1 caused a decrease in the peak val-ues of Ca2+]i transient change.