生理性和病理性心肌肥厚组织中心钠素表达的差异研究

A study on the differential expressions of atrial natriuretic peptide in physiological and pathological myocardial hypertrophy tissues

目的研究心钠素(ANP)在生理性和病理性心肌肥厚组织中表达的差异及其在心肌肥厚发生、发展中的作用。方法选择无特定病原体(SPF)级8周龄雄性Sprague-Dawley(SD)大鼠15只,随机分为对照组(CON组)、异丙肾上腺素组(ISO组)和运动组(EXE组),每组5只。ISO组通过颈部多点皮下注射异丙肾上腺素构建病理性心肌肥厚模型。EXE组采用有氧运动(游泳)诱导生理性心肌肥厚。CON组不予特殊干预。在第8周末采用过量麻醉法处死大鼠,取心脏组织。采用HE染色法观察心脏组织病理、生理改变情况。采用Western-blot法和免疫组化染色法检测三组心肌组织中ANP的表达情况。结果与CON组相比,EXE组和ISO组的心肌纤维明显增粗,且ISO组还出现了心肌纤维间隙增宽、排列紊乱等结构受损的特征,而EXE组的心肌纤维则排列整齐,结构完整。ANP主要表达于心肌细胞的胞浆中,ISO组ANP表达水平高于EXE组和CON组,差异有统计学意义(P<0.05)。结论ANP在病理性心肌肥厚组织中表达升高,可作为鉴别生理性和病理性心肌肥厚的辅助性指标。

Objective To study the differential expressions of atrial natriuretic peptide(ANP)in physiological and pathological myocardial hypertrophy tissues,and its role in the occurrence and development of myocardial hypertrophy.Methods Fifteen specific pathogen-free(SPF)grade 8-week-old male Sprague-Dawley(SD)rats were selected and randomly divided into control group(CON group),isoproterenol group(ISO group)and exercise group(EXE group),with 5 rats in each group.In the ISO group,the pathological myocardial hypertrophy model was established by subcutaneous injection of isoproterenol at multiple points in the neck.Physiological myocardial hypertrophy was induced by aerobic exercise(swimming)in the EXE group.The CON group received no special intervention.At the end of the 8th week,the rats were sacrificed by overdose anesthesia,and the heart tissues were harvested.Hematoxylin and eosin(HE)staining was used to observe the pathological and physiological changes of heart tissues.Western-blot and immunohistochemical staining were used to detect the expressions of ANP in the myocardial tissues in the three groups.Results Compared with those in the CON group,the myocardial fibers in the EXE group and the ISO group were significantly thickened,and the ISO group also had the characteristics of structural damages such as widening of myocardial fiber gaps and disordered arrangement.However,the myocardial fibers in the EXE group were neatly arranged and structurally intact.ANP was mainly expressed in the cytoplasm of myocardial cells.The expression level of ANP in the ISO group was higher than that in the EXE group and the CON group,and the differences were statistically significant(P<0.05).Conclusion The expression of ANP is elevated in pathological myocardial hypertrophy tissues and ANP can be used as an auxiliary indicator to distinguish physiological myocardial hypertrophy from pathological myocardial hypertrophy.