目的对比分析老年和青年大鼠大脑皮质及肝脏内参基因的转录表达情况,探讨老年大鼠大脑皮质、肝脏基因转录分析中内参基因的选择。方法以老年和青年SD大鼠为研究对象,用反转录PCR方法测定3-磷酸甘油醛脱氢酶(GAPDH)、β-肌动蛋白(β-actin)、18S核糖体RNA(18S rRNA)在老年和青年大鼠大脑皮质、肝脏中的表达稳定性。结果老年大脑皮质GAPDH和β-actin mRNA表达水平与青年相比差异无统计学意义,以GAPDH更为稳定,老年大脑皮质18SrRNAmRNA表达降低;老年肝脏β-actin和GAPDH mRNA表达水平与青年相比差异无统计学意义,以β-actin更为稳定,老年肝脏18S rRNA mRNA表达升高。内参基因在老年大脑皮质的变异系数由小到大依次为GAPDH﹤18SrRNA﹤β-actin,在老年肝脏依次为β-actin﹤GAPDH﹤18S rRNA。内参基因在青年大脑皮质的变异系数依次为β-actin﹤GAPDH﹤18S rRNA,在青年肝脏依次为β-actin﹤18S rRNA﹤GAPDH。结论 GAPDH在老年大鼠大脑皮质中表达最为稳定,β-actin在老年大鼠肝脏中表达最为稳定。 Objective To comparatively analyze the transcriptional expression of the cortex and liver genes in aged and young rats and to explore the selection of the genes involved in gene transcription analysis in the cerebral cortex and liver of the aged rats. Methods The aged and young SD rats were used as experimental objects. GAPDH, β-actin and 18S ribosomal RNA (18S rRNA) were determined by reverse transcription polymerase chain reaction (RT-PCR) Expression stability in cerebral cortex and liver of aged and young rats. Results The expression of GAPDH and β-actin mRNA in the cerebral cortex of aged patients was not significantly different from that of the youth, GAPDH was more stable, and the expression of 18SrRNA mRNA was decreased in the aged cerebral cortex. The expression of β-actin and GAPDH mRNA in the aged liver was significantly lower than that of the youth No statistical significance, to β-actin more stable, elderly liver 18S rRNA mRNA expression increased. The coefficients of variation of internal reference genes in the elderly cerebral cortex were GAPDH <18SrRNA <β-actin in turn and β-actin