自发性高血压大鼠下丘脑视上核和室旁核γ-adducin表达的增龄改变及高盐摄入的影响

Effects of aging and salt loading on expression of γ-adducin in hypothalamic supraoptic and paraventricular nuclei of spontaneously hypertensive rats

目的:观察自发性高血压大鼠(SHR)下丘脑视上核和室旁核γ-adducin表达的增龄变化,以及高盐摄入的影响.方法:将60只SHR按年龄分幼年组(5wk),成年组(25wk),老年组(49wk),每组20只,测各年龄组SHR尾动脉收缩压;各年龄组随机分为两亚组,分别给予正常盐饮食和高盐饮食喂养3wk;复测血压比较各年龄组正常盐(9g/LNaCl)和高盐(40g/LNaCl)喂养后收缩压的变化;SHR大脑灌注取材,应用免疫组化SABC染色检测SHR下丘脑视上核和室旁核γ-adducin的增龄性表达及高盐喂养的影响.结果:SHR血压随着年龄增加呈递增趋势(P<0.01),高盐喂养能明显升高这种增龄性改变(P<0.01).下丘脑视上核和室旁核中γ-ad-ducin的灰度值均随年龄增长呈递增趋势,即γ-adducin的表达均随年龄增长呈递减趋势.各年龄段内高、正常盐亚组间比较,下丘脑视上核和室旁核中γ-adducin的表达均无统计学差异(P>0.05).结论:SHR血压随着年龄的增长呈逐渐升高趋势,下丘脑视上核和室旁核γ-adducin表达随年龄增长均呈递减趋势,高盐干预对大鼠下丘脑视上核和室旁核γ-addu-cin表达无明显影响.

AIM： To examine whether the expression of γ-adducin （ one subunit of adducin） alters in the hypothalamic supraoptic and paraventricular nuclei （SON and PVN） of spontaneously hypertensive rats （SHR） with aging, and to evaluate the effect of sodimn loading on the expression of γ-adducin in SON and PVN of SHR. METHODS： According to the age of the rats, 60 male SHR were divided into 3 groups： infant group （5 wk）, adult group （25 wk） and aged group （49 wk） （ n = 20 in each group）. After 1-week normal diet, each group was randomly divided into 2 subgroups： respectively fed normal-salt （9 g/L NaC1） or high-salt （40 g/L NaC1） rat chow for 3 weeks. We set up a two-phased study： the systolic blood pressure （SBP） of SHR was measured and analyzed by a tail-cuff method before and after sodium loading ; the expression of γ-adducin in the SON and PVN of SHR was assessed by immunohistochemical SABC staining. RESULTS： SBP of SHR significantly increased with aging （P 〈0.01 ）. Compared to SHR with normal-salt diet, SBP of SHR with high-salt diet remarkably increased （P 〈 0.01 ）. The expression of γ-adducin decreased in the SON and PVN of SHR with aging. In the expression of γ-adducin in the SON and PVN of SHR, no significant difference was found between the normal-salt and high-salt subgroups （P 〉 0. 05 ）. CONCLUSION： The blood pressure of SHR increases with aging and high-salt diet. The expression of γ- adducin decreases in the SON and PVN of SHR with aging. There is no significant change in the expression of γ-adducin in the SON and PVN of SHR with short-term sodium loading.