高盐饮食对大鼠左室肥厚的影响

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 1含量的增加可能是SHR左室肥厚的原因之一

Salt Induces Left Ventricular Hypertrophy in Rats

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.