异丙肾上腺素所致小鼠心肌肥厚中核仁素的表达

Expression of Nucleolin in Myocardial Hypertrophy Mice Induced by Isoproterenol

目的探讨异丙肾上腺素(ISO)所致小鼠心肌肥厚(hypertrophy)中核仁素的表达情况。方法采用体重18～22 g小鼠,随机分为3组(n=10):生理盐水组、小剂量异丙肾上腺素组(ISO每天100 mg/kg)、大剂量异丙肾上腺素组(ISO每天150 mg/kg),连续注药1周后,称体重(BW),从心脏取血测定MDA、LDH和CK含量,取全心称重(HW);光镜下观察心肌病理形态学改变;免疫组织化学法及Western-blot检测核仁素的表达情况。结果 (1)小剂量异丙肾上腺素组小鼠心肌纤维增粗,心肌细胞呈束状分布,排列较整齐,而大剂量异丙肾上腺素组心肌纤维增粗,排列紊乱,纤维组织增生,染色不均匀。与生理盐水组相比,小剂量异丙肾上腺素组、大剂量异丙肾上腺素组小鼠心脏重量参数HW/BW显著增加(P<0.05);(2)与生理盐水组相比,大、小剂量异丙肾上腺素组小鼠血清MDA、LDH、CK含量升高(P<0.05);(3)与生理盐水组相比,小剂量异丙肾上腺素组小鼠心肌核仁素蛋白表达上调(P<0.05),而大剂量异丙肾上腺素组小鼠心肌核仁素的表达无明显改变。结论小剂量异丙肾上腺素所致小鼠心肌肥厚中核仁素的表达上调,而大剂量异丙肾上腺素所致小鼠心肌肥厚中核仁素的表达改变不明显。

Objective Nucleolin （C23） is an important RNA-binding protein which has an effect on the proliferation and growth of cells. Recent study reveals that nucleolin can protect myocardial from ischemia-reperfusion injury. However,whether nucleolin plays a role in the cardiac myocyte hypertrophy remains unclear. We set out to detect the nucleolin in cardiac hypertrophy mice induced by administration of isoproterenol （ISO）. Method C57/BLG6 mice with body weight between 18 and 22 g were recruited and randomly divided into three groups. A murine model of cardiac hypertrophy was employed by administering isoproterenol （ISO） subcutaneously for 7 days. Cardiac hypertrophy was quantified by heart weightto-body weight ratios （HWI）. We detected nucleolin by immunohistochemistry analysis and western-blot analysis. Result （ 1 ） Myocardial hypertrophy were observed in mice induced by low dosage of ISO （ 100 mg/kg · d） and even more significant in mice induced by high dosage of ISO （ 150 mg/kg · d） compared with the vehicle control group（P 〈0. 05）. （2）Elevated MDA, LDH and CK were observed in serum of low dosage group and were more remarkable in high dosage group in contrast to vehicle control group（ P 〈 0. 05 ）. （3）Nucleolin in low dosage group was higher than that in vehicle control group but it changed little in high dosage group （P 〈 0. 05 ）. Conclusion Nucleolin in myocardial hypertrophy mice induced by low dosage of ISO was up-regulated while it is not significantly changed in mice induced by high dosage of ISO.