普萘洛尔和苄普地尔减轻左甲状腺素诱导的大鼠心脏肥大以及线粒体Ca2+ Mg(2+)-ATP酶活性升高。

Propranolol and bepridil attenuating levothyroxine-induced rat cardiac hypertrophy and mitochondrial Ca2+ Mg(2+)-ATPase activity elevation.

作者信息

Chen D D, Dai D Z, Lu J, Zhang X K

机构信息

Research Division of Pharmacology, China Pharmaceutical University, Nanjing, China.

出版信息

Zhongguo Yao Li Xue Bao. 1996 Nov;17(6):516-8.

PMID:9863145

Abstract

AIM

To study the effects of propranolol and bepridil on levothyroxine-induced rat cardiac hypertrophy and mitochondrial Ca2+ Mg(2+)-ATPase activity elevation.

METHODS

Rat heart hypertrophy was induced by i.p., levothyroxine 1 mg.kg-1.d-1 x 10 d. Then rats were treated by ig propranolol (Pro) or bepridil (Bep) 10 mg.kg-1 daily. Ca2+ Mg(2+)-ATPase activity and enzyme kinetic parameters were assayed.

RESULTS

The activity and Vmax of mitochondrial Ca2+ Mg(2+)-ATPase isolated from hypertrophic left ventricle were 25 +/- 4 and 35.1 +/- 0.8 mumol Pi.h-1/mg protein, respectively, those of normal were 6.7 +/- 1.8 and 10 +/- 4 mumol Pi.h-1/mg protein, respectively. Apparent K(m) of the hypertrophic group Ca2+ Mg(2+)-ATPase was 0.4 +/- 0.12 mmol.L-1 ATP, and that of normal was 0.59 +/- 0.22 mmol.L-1 ATP. The total protein quantity of hypertrophic left ventricle was 80 +/- 30 mg, and that of normal was 47 +/- 9 mg. After treated with Pro or Bep (both 10 mg.kg-1 ig), the cardiac hypertrophy was attenuated, the enzyme activity and Vmax as well as total protein quantity of hypertrophic left ventricle were reduced to normal level, but apparent K(m) was not affected.

CONCLUSION

Both Pro and Bep prevented the myocardium and its mitochondria from ischemia and overload calcium injury.

摘要

目的

研究普萘洛尔和苄普地尔对左甲状腺素诱导的大鼠心脏肥大及线粒体Ca2+ Mg(2+)-ATP酶活性升高的影响。

方法

腹腔注射1 mg.kg-1.d-1的左甲状腺素，连续10天诱导大鼠心脏肥大。然后，大鼠每天灌胃给予10 mg.kg-1的普萘洛尔（Pro）或苄普地尔（Bep）。测定Ca2+ Mg(2+)-ATP酶活性和酶动力学参数。

结果

从肥大左心室分离的线粒体Ca2+ Mg(2+)-ATP酶的活性和Vmax分别为25±4和35.1±0.8 μmol Pi.h-1/mg蛋白，正常组分别为6.7±1.8和10±4 μmol Pi.h-1/mg蛋白。肥大组Ca2+ Mg(2+)-ATP酶的表观K(m)为0.4±0.12 mmol.L-1 ATP，正常组为0.59±0.22 mmol.L-1 ATP。肥大左心室的总蛋白量为80±30 mg，正常组为47±9 mg。用Pro或Bep（均为10 mg.kg-1灌胃）治疗后，心脏肥大减轻，肥大左心室的酶活性、Vmax以及总蛋白量降至正常水平，但表观K(m)未受影响。