【摘要】 我们前期研究表明运动性和高血压性心肌肥大细胞表型变化在结构、功能和代谢方面均表现不同，但两者基因表达的不同特征尚不清楚。本实验采用Northern分子杂交方法对游泳运动12周大鼠和自发性高血压大鼠（spontaneouslyhypertensiverat,SHR）肥大心脏心肌初级和次级应答基因表达进行比较研究。结果表明，游泳大鼠心系数比对照大鼠提高26％（P＜0．01），心肌c－fos和心房钠尿肽（atrialnatriuretic，ANF）基因表达在最后一次运动后即刻明显增强，在运动后24h的稳定期，c－fos基因表达降低，但仍高于对照大鼠，而ANF基因表达则降低至对照大鼠水平；肌球蛋白α重链（myosinheavychain，MHC）基因表达增强，α／β-MHC基因表达比值提高。SHR心系数比对照大鼠提高61％（P＜0．01），心肌c-fos和ANF基因表达呈持续增强，β-MHC基因表达增强，α／βMHC基因表达比值降低。这些结果说明，运动性和高血压性心肌肥大重塑时心肌的初级和次级应答基因表达特征不同。本文提示：（1）c-fos等原癌基因的不同表达可能对两种心肌肥大的重塑具有不同的调节作用；（2）ANF基因的不同表达可作为在转录水平上区别两种不同心肌肥大的分子标志；（3）α／β-MHC基因比值的不同表达可在转录水平上调节运动性和高血压性肥大心脏?更多还原

【Abstract】 Our previous studies have shown that the myocardial phenotypes between exerciseinduced and hrpertensive cardiac hypertrophy are different. However, alteration ofcardiac gene expression in the two kinds of hypertrophy is not clear. We therefore studiedthe expression of immediate early and late responsive gene in Wistar rats subject to a 12weeks swimming program and spontaneously hrpertensive rats (SHR) by Northern blot.The autoradiographs were analyzed by scanning densitometry. When compared withmatched sedentary control, swimming rats and SHR increased their heart/body weight by29% and 61% respectively (P<0.01). After a series of swiming program, levels ofc-fos and atrial natriuretic factor (ANF) mRNA were instantly increased 203% and214% respectively in the swimming rats. However in 24 h after swimming, ANF mRNAwas decreased to the level of control but c-fos mRNA was still higher than that in control.The levels of c-fos and ANF mRNA were increased by 80% and 298% in SHRrespectively. The expression of β-myosin heavy chain (MHC) mRNA was increased by117% in SHR but decreased by 12% in swimming rats. The expression of α-MHC mRNAwas decreased by 42% in SHR but unchanged in swimming rats. The abundance α/βMHC mRNA in swimming rats is 336% higher than in SHR. These results showeddifferential expression of the immediate early and late responsive gene in exercise-inducedand SHR hypethephied heart remodeling. It is suggested that (1) the differentialexpression of c-fos gene may differently regulate remodeling of these two cardiachypertrophies; (2) the differential expression of ANF gene may be a molecular marker fordistingUishing the two kinds of cardiac hypertrophy; and (3) the differential expression ofα/β-MHC gene ratio may regulate exercise-induced and hypertensive hypertrophiedmyocardial cell changing to contractile phenotype and synthehetic phenotype respectively, atthe gene transcription level.更多还原