肾上腺髓质素对自发性高血压大鼠心脏重构的影响

Protective Effect of Adrenomedullin on Heart Remodeling of SHR

目的对比研究肾上腺髓质素(ADM)对自发性高血压大鼠(SHR)心脏重构和血压的影响。方法 4周龄32只雄性SHR随机分为SHR组和SHR-T组,同周龄16只雄性WKY大鼠作为正常对照,每组4、8、16、24周龄各4只。SHR-T组皮下注射ADM(每周5d,1.0nmol.(kg.d)-1),SHR组皮下注射等量生理盐水,WKY组不作处理。每周测量1次尾动脉收缩压(SBP)。4、8、16、24周龄时间点提取心脏,切片HE染色,显微测微尺观测心脏结构变化。结果 8周龄开始,SHR组和SHR-T组大鼠血压显著高于WKY组(P<0.01),ADM治疗至24周龄时,SHR-T组血压明显低于SHR组(P<0.05)。组织学显示24周龄SHR-T组大鼠高血压所致的心肌细胞肥大和排列紧密现象较SHR组有一定程度的改善。8周龄始,SHR逐渐出现左心室肥厚。ADM治疗至24周龄时,SHR-T组动脉血压、心脏/体重比值、相对左心室壁厚度低于SHR组(P<0.05)。结论 ADM有效降低了SHR血压并在一定程度上抑制了高血压时心脏重构。

Objective To investigate the effects of adrenomedullin on remodeling of heart and blood pressure in spontaneous hypertension rats（SHR）. Methods Thirty - two 4 week - old male SHR were randomizedly divided into SHR group and SHR -T group,matched 16 WKY rats as control （WKY）. Each group had 4 in different period. SHR -T group rats were subcutaneously injected with ADM [Sdays/week,1.0nmol·（kg·d） -1 ], normal saline instead of ADM for SHR group rats. Tail - cuff systolic blood pressure （SBP） was measured at the end of every week. The rats were sacrificed at 4,8,16,24 week -old, heart was harvested. The morphological changes were observed by HE staining. Results From 8 weeks old, SBP level of SHR group and SHR - T group were higher than that of WKY group （P 〈0.01 ）. However,decreased SBP was detected at 24 week in SHR - T group （ P 〈 0, 05 ）. Histology showed 24 week - old SHR - T group myocardial cell hypertro- phy and closely arrange had significantly alleviated compared to SHR group. Hypertrophy of left ventricular wall appeared at 8 week - old SHR. SBP, heart weight （HW） / body weight （ BW）, relative left ventrieular wall thickness （RLVWT）（ left ventricular wall thickness/maximum ventricular diameter）at 24 week-old SHR- T group decreased compare with that of SHR group （P 〈 0.05 ）. Conclusion ADM effectively decreased SHR SBP and to some extent attenuated heart remodeling induced by hypertension.