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衰老大鼠心脏与主动脉G蛋白#alpha#亚基的变化

周元国, 熊仁平, 王正国

(第三军医大学野战外科研究所四室，重庆630042)

摘要

随着年龄的增长，心血管系统鸟昔酸结合蛋白(简称G蛋白)藕联受体介导的反应性也发
生了改变。本文用Western Blot和核酸杂交技术分别观察了6,24月龄的Fischer 344大鼠主动脉、心房、心室及脑组织中Gsa, Goa, Gia及其相应的mRNA的变化。结果显示，主动脉Gsa含4个带(38, 42, 45和52 kD)，其中42 kD带在24月龄大鼠显著下降(P<0. 05 ), Goa和Gia各为单一带(39 kD和41 kD)，两者24月龄也有显著下降((P<0. 05)，但它们的mRNA水平未见显著改变;心房、心室中Gs a有三个带((52, 45和42 kD), Goa和Gia各为一个带，在24月龄大鼠三者均未见显著改变，但Gi2a和Gi 3 a mRNA的含量显著增加((P<0. 05)。上述结果提示:Gi a, Goa的表达水平下降可能是衰老血管组织受体反应性下降的分子基础之一。

关键词： G蛋白; 衰老; 心血管; 大鼠; 信息传导

ALTERATIONS OF G PROTEIN ALPHA SUBUNITS IN HEART AND AORTA OF OLD RAT

ZHOU YUAN-GUO, XIONG REN-PING , WANG ZHENG-GUO

Deyartnmt 4，The Research Institute of Surgery, The Third Military Medical University, Chongqing 630042)

Abstract

Alterations in responsiveness to stimulation of G protein-coupled receptors in the cardiovascular system have been noted during aging and may be due to changes in the G proteins. The levels of G protein a subunits (Gs a, Go a and Gi a) and their mRNAs(Gs a，Go a，Gi 2a and Gi 3a) were examined in the aorta，heart，and brain of 6 and 24 month old fischer 344 rats by Western blot analysis，quantitative RNA dot blot hybridization and Northern Blot analysis. There were four bands (52，45，42 and 38 kD)in the aorta for Gsa. The 42 kD band decreased significantly in 24 month old rats (69. 2士0.2%，PCO. 05)，while the other bands did not change. The Go a and the Gi a contain spectively only a band of 39 kD and of 41 kD which decreased signify cantly in the 24 month rats by 71. 8士10. 70o and 63. 1士10. 40o;There were no significant changes in the level of Ga mRNA between 6 and 24 month old rats. In the
heart anti-Gsa antiserum could detect 3 bands(52，4 5 and 4 2 kD) which did not
change during aging;the levels of Gi a and Go a also did not change，but the mRNAs for Gi 2a and Gi 3a were significantly increased respectively to 120. 8士8. 4%and 136. 4士14. 2%.The above results indicated that the decrease of levels of Gi a Goa expression may be the molecular basis for the alterations in signal transduction and biological response of aging aorta and heart.

Key words: G proteins;Aging;cardiovascular;Rats;signal transduction

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引用本文：

周元国, 熊仁平, 王正国. 衰老大鼠心脏与主动脉G蛋白#alpha#亚基的变化[J]. 生理学报 1996; 48 (3): .

ZHOU YUAN-GUO, XIONG REN-PING , WANG ZHENG-GUO. ALTERATIONS OF G PROTEIN ALPHA SUBUNITS IN HEART AND AORTA OF OLD RAT. Acta Physiol Sin 1996; 48 (3): (in Chinese with English abstract).