老年大鼠心脏肾上腺素受体亚型的改变

摘要

AIM: To determine alterations of subtypes of myocardial adrenoceptors in senescence.METHODS: Heart membrane preparations were made from 3- and 25-month old Wistar rats. α1- and β-adrenoceptors were measured by radioligand, 125I-BE2254 and 125I-pindolol, binding assays, respectively. RESULTS: In the old rat heart, α1- and β-adrenoceptor densities were declined from the young rats of 119±4 and 45.9±1.9 pmol L-1 to 70±6 and 36.4±1.6 pmol L-1(P＜0.01), with a greater change in α1-AR and in β-AR. The ratio of α1A/α1B subtypes was decreased from the young rats of 39/61 to the old rats of 26/74 (P＜0.05). CONCLUSION: The cardiac adrenoceptors are decreased with different extents in the different subtypes in old rats.%目的:研究老年心脏肾上腺素受体亚型的改变.方法:制备3月龄与25月龄Wistar大鼠心脏膜标本,分别采用125Ⅰ-BE2254与125Ⅰ-Pindold作放射配基结合分析,测定α1与β-肾上腺素受体.结果:老年大鼠心脏的α1与β-肾上腺受体密度分别由年轻大鼠的119±4与45.9±1.9pmol/g下降至70±6与36.4±1.6 pmol/g(P＜0.01),α1-AR降低的幅度大于β-AR.此外α1A与α1B亚型之比由年轻大鼠的39:61下降至26:74(P＜0.05).结论:老年大鼠心脏肾上腺素受体减少,且不同亚型减少的程度不同.