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咖啡因和茶碱对大鼠皂素蜕膜心肌肌钙蛋白 Ca~(2+)敏感性和肌浆网Ca~(2+)释放的影响

黄焰, 贺振翩, 李云霞

(湖南医科大学心血管生理研究室，长沙410078)

摘要

在低浓度皂素(50 ug/ml)制备的浆膜蜕变(通透性增高)而肌浆网((SR)膜无损的蜕膜心
肌标本上，以其收缩的幅度作为SR Ca~(2+)一释放的半定量指标;高浓度皂素(500 ug/ml)制备的浆膜和SR膜均蜕变的蜕膜心肌标本，以其张力一pCa关系曲线以及产生50%最大张力所需的Ca~(2+)浓度(pCaso)分别作为肌钙蛋白(TN) Cat~(2+)敏感性的定性和定量指标。结果观察到:(1)在低浓度皂素蜕膜心肌标本上，5和10 mmol/L咖啡因分别引起约89. 2士12. 7和142. 5士17 mg(n=4, P<0.05)张力的强直收缩，而5 mmol/L茶碱未能引起明显的强直收缩;(2)在高浓度皂素蜕膜心肌标本上，5和10 mmol/L咖啡因及5 mmol/L茶碱均使张力一pCa关系曲线左移;pCaso较对照分别增加了0.261, 0.274和0. 212 pCa单位(P均小于0.001)。上述结果提示:咖啡因和茶碱均能增高TNCa~(2+)+敏感性;此外，咖啡因尚有促使SR释放Ca~(2+)的作用。

关键词： 皂素; 肌钙蛋白Ca~(2+)敏感性; 肌浆网Ca~(2+)释放; 蜕膜心肌; 咖啡因; 茶碱; 大鼠

EFFECT OF CAFFEINE AND THEOPHYLLINE ON Ca~(2+) SENSITIVITY OF TROPONIN AND Ca ~(2+) RELEASEFROM SR IN SAPONIN-SKINNED RAT CARDIAC MUSCLE

HUANG YAN, HE ZHEN-HE, LI YUN-XIA

(Laboratory of Cardiovacular Physiology, Human Medical University, Changslta 910078)

Abstract

Cell membrane of cardiac muscle fiber (rat right ventricular papillary muscle) was chemically skinned(permeability of membrane increased)by treatment with saponin at low concentration (50 pg/ml)，while the function of sarcoplasmic reticulum (SR) was preserved. The strength of rigor contraction of the skinned fiber was used as a semi- quantitative index of the ability of SR to release Ca~(2+).When treated with saponin at high concentration(500 4g/ml)，both sarcolemma and membrane of SR were skinned. Tension一pCa relationship and the Cat一concentration required for producing 5 0%of maximum Ca~(2+)activated tension (pCaso)were respectively taken as qualitative and quantitative index of Cat一sensitivity of troponin (TN).The results showed:
(1)In low saponin skinned fiber，5 and 10 mmol/L caffeine respectively produced
89.2士12. 7 and 142. 5士17 mg (n = 4) rigor contraction，5 mmol/L theophylline did not have this effect.(2)In high saponin skinned fiber 5 mmol/L theophylline，5 and 10 mmol/L caffeine shifted the tension-pCa relationship curve to the left，pCa5o respectively increased by 0. 212，0. 261 and 0. 274 pCa units. These results suggest that caffeine and theophylline increase the Cat~(2+)sensitivity of TN and caffeine can also induce Cat~(2+) release from SR.

Key words: Key words:saponin;;;;;;

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引用本文：

黄焰, 贺振翩, 李云霞. 咖啡因和茶碱对大鼠皂素蜕膜心肌肌钙蛋白 Ca~(2+)敏感性和肌浆网Ca~(2+)释放的影响[J]. 生理学报 1997; 49 (2): .

HUANG YAN, HE ZHEN-HE, LI YUN-XIA. EFFECT OF CAFFEINE AND THEOPHYLLINE ON Ca~(2+) SENSITIVITY OF TROPONIN AND Ca ~(2+) RELEASEFROM SR IN SAPONIN-SKINNED RAT CARDIAC MUSCLE . Acta Physiol Sin 1997; 49 (2): (in Chinese with English abstract).