衰老对大鼠阴茎海绵体NOSⅠ的表达和NOS活性的影响

目的 :探讨衰老对大鼠阴茎海绵体一氧化氮合酶Ⅰ (NOSⅠ)mRNA、蛋白的表达和NOS活性的影响。　方法 :30只雄性SD大鼠按不同月龄分为成年组、老年组和衰老组 ,应用Western印迹、RT PCR方法分别检测不同年龄组阴茎海绵体NOSⅠ蛋白及mRNA的表达 ;用紫外分光光度计测定不同年龄组阴茎海绵体NOS的活性。　结果 :成年组NOSⅠ 蛋白的表达量最高 ,老年组和衰老组显著降低 ,分别为成年组的 75 .6 %和 6 1.2 % ;NOSⅠmRNA的表达与蛋白表达的变化一致 ;老年组NOS活性与成年组差异无显著性 (P >0 .0 5 ) ,衰老组NOS活性明显降低 ,是成年组的70 .4 % ,并且差异非常显著 (P <0 .0 1)。　结论 :衰老引起NOSⅠ 蛋白及mRNA的表达降低和NOS活性的显著降低 ,可能是老年性阴茎勃起功能障碍的主要机制之一。

Effect of Aging on the Expression of Nitric Oxide Synthase Ⅰ and the Activity of Nitric Oxide Synthase in the Rat Penis

Objectives: To investigate the effect of aging on the expression of nitric oxide synthaseⅠ(NOSⅠ) and the activity of nitric oxide synthase in the rat penis. Methods: Thirty male rats from three age groups(adult, old and senescent) were investigated: ①The expressions of NOSⅠprotein and mRNA in the penis were detected by Western blot and RT PCR, respectively. ② NOS activity in the penis was detected with ultraviolet spectrophotometry. Results: In rats of the old and the senescent groups, the expression of NOSⅠ protein decreased significantly as compared to that of the adult group. NOSⅠmRNA expression was well related to its protein expression. NOS activity had no statistical difference between the adult group and the old group, but it reduced significantly in the senescent group as compared to that of the adult group( P < 0.01 ). Conclusions: It is maybe one of the main mechanisms of erectile dysfunction in the aging male that the aging causes the decreases of NOSⅠprotein and mRNA expression and NOS activity.