复合离子盐对高血压大鼠肾脏皮质磷酸化ERK1/2表达的影响

目的：观察复合离子盐对自发性高血压大鼠（SHR）肾脏皮质磷酸化ERK1／2（p-ERK1／2）表达的影响．探讨复合离子盐对SHR肾脏保护作用的可能机制。方法：38只8周龄雄性SHR随机分为4组，8％食盐摄入组（US组）；1％复合离子盐摄入组（CIS组）；1％复合离子盐＋2．25％L-精氨酸摄入组（CIS＋L-Arg组）；1％食盐摄入组（NS组）．持续干预12周。干预期间定期观察大鼠体质量、血压、尿量的变化；干预结束后处死动物。进行肾脏组织HE及天狼猩红染色，观察病理变化并计算胶原容积分数；并通过western-blot法分析SHR肾脏皮质磷酸化ERK1／2蛋白表达的情况。结果：12周干预结束后，CIS组与CIS＋L-Arg组血压升高趋势明显低于NS组（P〈0．01）。与NS组相比，CIS组与CIS＋L-Arg组SHR肾小球及肾小管周胶原沉积量少，肾脏损害较轻，HS组SHR肾小球及肾小管周胶原沉积明显增多，肾脏损害较重，同时P-ERK1／2的表达在HS组明显增加，而p-ERK1的表达在CIS组与CIS＋L-Arg组明显降低（P〈0．05）。结论：复合离子盐与复合离子盐＋L-Arg的摄入可能通过影响p-ERK1／2的表达减轻SHR肾脏功能结构的损害。

Effects of Compound-ion Salt on Expression of Phosphorylated ERK1/2 in Renal Cortex of Spontaneously Hypertensive Rats

Objective: To investigate the effects of compound-ion salt on expression of phosphorylated ERK1/2 (p- ERK1/2) in renal cortex of spontaneously hypertensive rats (SHR) and its renal protective mechanism to SHR. Methods: SHR with eight weeks (male, n=38) were randomly into four groups: the density of 8% salt intake group(HS group);the density of 1% compound-ion salt intake group(CIS group); the density of 1% compound-ion salt plus 2.25% L-Arg intake group (CIS L-Arg group) and the density of 1% normal salt intake group(NS group) for 12 weeks. Blood pressure, body weight and urine volume were measured periodly throughout all experiments.After intervention, all rats were sacrificed and blood was collected to make renal tissue HE and scarlet red stain then pathological changes were observed and collagen volume fraction was evaluated. The protein expression of phosphorylated ERK1/2 in renal cortex of SHR was analyzed by Western blot. Results: The compound-ion salt and compound-ion salt plus L-Arg intake groups were able to apparently delay the blood pressure increase compared with the normal-salt diet group(P < 0.01) after twelve week intervention, glomerular and tubular interstitial collagen deposit of SHR were lower and kidney injury was not serious in the CIS and CIS plus L-Arg intake groups.On the other hand, glomerular and tubular interstitial collagen deposit of SHR increased and kidney injury was serious in the HS group compared with the NS group as well as compound-ion salt and compound-ion salt L-Arg intake cut down the expression of p-ERK1 in renal tissue but high salt intake augmented the expression of p-ERK1/2 in renal tissue (P<0.05). Conclusion: Compound-ion salt and compound-ion salt L-Arg intake can ameliorate the progression of kidney injury of SHR through regulating the protein expression of p-ERK1/2.