高盐饮食对大鼠左室肥厚的影响

Salt Induces Left Ventricular Hypertrophy in Rats

目的 观察高盐饮食对原发性高血压大鼠 (SHR)及正常血压大鼠 (WKY)左室肥厚的影响 ,并探讨其可能机制。方法 SHR和WKY各 2 0只分别分为两组 :( 1)高盐饮食组SHRSL(n =10 )和WKYSL(n =10 )饮用含 2 %NaCl盐水 ;( 2 )正常盐饮食组SHRNS(n =10 )和WKYNS(n =10 )饮用不含NaCl清水 ,共饲养 6周。测量左室重量指数 (LVI) ,心肌细胞直径(CMD) ,放免测定循环ANP以及心肌局部ET 1含量。结果 ( 1)左室重量指数及心肌细胞直径SHRSL较SHRNS显著增加(P <0 0 1) ,WKYSL较WKYNS有所增加 ,但差异不显著 (P >0 0 5 ) ;( 2循环中ANP浓度WKYSL较WKYNS明显升高 (P <0 0 1) ,SHRSL较SHRNS无明显差别 (P >0 0 5 ) ;( 3 )左室局部ET 1:SHRSL较SHRNS显著增加 (P <0 0 1) ,WKYSL较WKYNS无明显差别 (P >0 0 5 )。结论 高盐饮食可引起SHR左室肥厚 ,盐负荷后SHR心肌局部ET

Objective\ To investigate whether high salt intake resulted in left ventricular hypertrophy(LVH) in both SHR and WKY, and the involvement of ET\|1 in the developement of LVH.\ Methods\ SHR(\%n\%=20) and WKY(\%n\%=20) were randomized to receive a normal (drinking water; SHR\-\{NS\} and WKY\-\{NS\}) or high\|NaCl (2% saline; SHR\-\{SL\} and WKY\-\{SL\}) diet for 6 weeks.\ Histological sections were stained with HE. Left ventricular weight index (LVI) was defined as the ratio of left ventricular weight to rat body weight.\ Cardiomyocyte diameter (CMD) was measured by a computer\|assisted procedure.\ Myocardial ET\|1 was measured by RIA.\ Results\ (1) High\|salt diet induced a significant increase of LVI and CMD in SHR(\%P\%<0.01); (2) In SHR\-\{SL\} group, the level of local myocardial ET\|1 was significant higher than that in SHR\-\{NS\} group(P<0.01), while the level of local myocardial ET-1 in WKY{SL} group and in WKY{NS} group was of little difference(P>0.05). Conclusion High-salt dietary induce LVH in both SHR and WKY. Local ET-1 induced by salt load in SHR is probably involved in the developement of LVH.