TMB-8对去甲肾上腺素和BHQ引起新生大鼠单个脑细胞内游离钙增高的影响  

EFFECT OF TMB 8 ON THE INCREASE OF INTRACELLULAR FREE CA 2+ INDUCED BY NE AND BHQ IN DISSOCIATED SINGLE RAT BRAIN CELL

作　　者：张孝清[1] 王斌[1] 张民英[1] 肖继皋[1] 

机构地区：[1]南京医科大学药理教研室

出　　处：《药学学报》1997年第10期726-730,共5页Acta Pharmaceutica Sinica

摘　　要：应用ＡＲＣＭＭＩＣ阳离子测定系统，研究ＴＭＢ８对体外新生ＳＤ大鼠单个脑细胞内游离钙的抑制作用及其机制。结果表明，在无细胞外钙情况下，静息［Ｃａ２＋］ｉ为７９±１３ｎｍｏｌ·Ｌ－１。ＴＭＢ８１０，３０μｍｏｌ·Ｌ－１能明显降低静息［Ｃａ２＋］ｉ。ＴＭＢ８１００μｍｏｌ·Ｌ－１对高钾去极化引起的［Ｃａ２＋］ｉ显著增高无明显影响。在细胞外钙为１３ｍｍｏｌ·Ｌ－１时，去甲肾上腺素诱导的细胞内［Ｃａ２＋］ｉ升高可部分被ＴＭＢ８抑制；ＴＭＢ８（３０μｍｏｌ·Ｌ－１）对ＢＨＱ引起的［Ｃａ２＋］ｉ的升高无明显抑制作用。而当细胞外液［Ｃａ２＋］ｉ为０时，ＴＭＢ８几乎完全抑制了去甲肾上腺素和ＢＨＱ的作用。提示ＴＭＢ８降低脑细胞内游离钙的作用机制是通过促使细胞内钙进入肌浆网以抑制内钙的释放，并通过饱和肌浆网内Ｃａ２＋间接地阻滞细胞膜钙通道。The inhibitory effect and mechanism of 8 (N,N′ diethylamino)octyl 3,4,5 trimethoxybenzoate hydrochloride (TMB 8) on the elevation of single intracellular free Ca 2+ concentration ([Ca 2+ ]i) induced by High K +, Norepinephrine(NE) and 2,5 Di(tert butyl) 1,4 benzohydroquinone (BHQ) in dissociated single rat brain cells were studied. The changes of [Ca 2+ ]i were reflected by the fluorescent indicator, Fura 2/AM, employed. In the absence of extracellular Ca 2+ , Ca free Hank′s solution, preincubation with TMB 8(10,30 μmol·L -1 ) for 20 min significantly decreased the resting [Ca 2+ ]i from 79±13 nmol·L -1 to 65±11 and 61±6 nmol·L -1 , respectively. [Ca 2+ ]i were markedly increased by NE and BHQ and reduced significantly to control level by TMB 8. On the other hand, when the cells were incubated in Hank′s solution containing Ca 2+ 1 3 mmol·L -1 , TMB 8(30,100 μmol·L -1 ) suppressed the increase of [Ca 2+ ]i induced by NE(0 0001～0 1 μmol·L -1 ). TMB 8 showed no significant effect on [Ca 2+ ]i elevation induced by KCl and BHQ in Hank′s solution containing Ca 2+ 1 3 mmol·L -1 . These results indicate that TMB 8 reduced [Ca 2+ ]i via increase of the sarcoplasmic reticulum (SR) sequestration, which blocked the release of intracellular store from the SR. However, the inhibitory effect of TMB 8 on Ca influx from extracellular medium seems to be an indirect action from the saturation of SR with calcium.

关 键 词：TMB-8 荧光指示剂 钙 去甲肾上腺素 BHQ 

分 类 号：R972[医药卫生—药品]