钙拮抗剂TMB-8抑制BHQ,NE和KCl引起的培养乳牛基底动脉单个平滑肌细胞内游离钙的升高

8 ( N,N DIETHYLAMINO) n OCTYL 3,4,5 TRIMETHOXYBENZOATE(TMB 8) REDUCED THE ELEVATION OF [Ca 2+ ]i INDUCED BY BHQ, NE AND KCl IN CULTURED SINGLE SMOOTH MUSCLE CELLS OF THE CALF BASILAR ARTERY

用ＡＲＣＭＭＩＣ阳离子测定系统，测量单个细胞内游离钙浓度（［Ｃａ２＋］ｉ），研究８（Ｎ，Ｎ二乙胺）ｎ辛基３，４，５三甲氧基苯甲酸酯（ＴＭＢ８）对培养乳牛基底动脉平滑肌［Ｃａ２＋］ｉ的作用。在细胞外钙浓度为１３ｍｍｏｌ·Ｌ－１时，ＴＭＢ８（３０μｍｏｌ·Ｌ－１）可明显抑制ＢＨＱ，ＮＥ及ＫＣｌ引起［Ｃａ２＋］ｉ的升高。在细胞外钙为零＋ＥＧＴＡ０１ｍｍｏｌ·Ｌ－１时，ＴＭＢ８（１０，３０及１００μｍｏｌ·Ｌ－１）可浓度依赖性地降低静息［Ｃａ２＋］ｉ，ＴＭＢ８（３０μｍｏｌ·Ｌ－１）可几乎完全阻断ＢＨＱ及ＮＥ引起［Ｃａ２＋］ｉ的增加。研究表明ＴＭＢ８降低培养乳牛基底动脉平滑肌［Ｃａ２＋］ｉ的机制，主要是抑制肌浆网Ｃａ２＋的释放，或增加肌浆网对Ｃａ２＋的摄入，并由此间接地抑制细胞外钙的内流。

The effect of 8 ( N,N diethylamino) n octyl 3,4,5 trimethoxybenzoate (TMB 8) on the elevation of [Ca 2+ ]i induced by 2,5 di(tert butyl) 1,4 benzohydroquinone (BHQ), norepinephrine (NE), KCl in cultured single smooth muscle cells of the calf basilar artery was studied by a system of measurement of AR CM MIC, using Fura 2/AM as a fluoresent indicator. In the presence of extracellular Ca 2+ 1 3 mmol·L -1 , the resting [Ca 2+ ]i was not changed by TMB 8 (10, 30 and 100 μmol·L -1 ), but the elevation of [Ca 2+ ]i induced by BHQ, NE and KCl were reduced by TMB 8 (30 μmol·L -1 ) significantly. In Ca 2+ free Hank′s solution containing EGTA 0 1 mmol·L -1 , the resting [Ca 2+ ]i was markedly reduced by TMB 8 (10,30 and 100 μmol·L -1 ), and the increase of [Ca 2+ ]i evoked by BHQ and NE was blocked completely by TMB 8 (30 μmol·L -1 ). The result suggested that TMB 8 inhibited the Ca 2+ release from intracellular stores or increased the up take of Ca 2+ into sarcoplasmic reticulum and the inhibition of Ca 2+ influx from extracellular site may be an indirect machanism.