铁皮石斛对异丙肾上腺素诱导心肌肥厚的保护作用

Protective effect of Dendrobium candidum on isoproterenol induced cardiac hypertrophy in rats

该文研究铁皮石斛对异丙肾上腺素（ISO）诱导的大鼠心肌肥厚影响及其作用机制。取健康SD大鼠60只，雌雄各半，随机分为5组，每组12只，即正常组，模型组，铁皮石斛样品低、中、高剂量组（0．09，0．18，1．1g·kg^-1）。除正常组外，其余各组每天背部皮下注射ISO（5mg·kg^-1）连续．10扎在注射ISO的同时，样品组开始灌胃给予不同剂量的铁皮石斛样品共30d，模型组给予同等量的生理盐水。颈总动脉插管检测各组左心室收缩压（LVSP）、计算左心室（LW）／胫骨长、心脏质量指数（HWI）和心肌羟脯氨酸含量（Hydro）；心肌组织HE染色观察心肌结构，MASSON染色观察心肌纤维化程度；酶联免疫分析（ELISA）检测血浆中心房利尿肽（ANP）、脑钠肽（BNP）、心肌肌钙蛋白I（cTN-I）浓度。结果显示，与正常组相比，ISO诱导大鼠心肌肥厚明显，且血浆中ANP、BNP和cTN-I的水平显著上升（P〈0．05）；与模型组相比，铁皮石斛样品能显著抑制ISO诱导的心室压力升高（P〈0．05）和心室肥厚，改善心肌纤维化，减少心肌胶原合成（P〈0．05），同时显著下调血浆ANP，BNP和cTN-I的水平（P〈0．05）。结果提示，铁皮石斛对异丙肾上腺素诱导的心肌肥厚具有保护作用。

To study the effect and mechanism of Dendrobium candidum on isoproterenol-induced myocardial hypertrophy in rats, 60 healthy SD rats （30 males and 30 females） were randomly divided into 5 groups （12 in each group） ： normal group, model group, three D. candidum preventive administration groups （0.09, 0. 18, 1.1 g·kg^-1）. Except for the normal group, rats of other groups were injected back subcutaneously with ISO （5 mg·kg^-1 ） for 10 consecutive days. At the same time, preventive administration groups began to give different doses of the sample for 30 days and model group began to give normal saline. Left ventricular systolic pressure （LVSP） was measured in each group by common carotid artery cannulation, and the left ventricle （LW）/tibia length, heart weight in- dex （HWI） and myocardial hydroxyproline （Hydro） content were calculated. Myocardial tissue HE staining and Masson staining were used to observe the myocardial structure and the degree of myocardial fibrosis respectively. Atrial natriuretic peptide （ ANP）, brain na- triuretic peptide （BNP）, and cardiac troponin I （cTN-I） concentration were measured by enzyme-linked immunosorbent assay （ELISA）. The results Showed that as compared with the normal group, the levels of ANP, BNP and cTN-I in plasma were significantly increased in ISO-induced hypertrophic rats; as compared with the model group, D. candidumcan inhibit ISO-induced ventricular pres- sure and ventricular hypertrophy, reduce myocardial collagen synthesis, improve myoeardial fibrosis and ventricular remodeling, and significantly down-regulate ANP, BNP and cTN-I levels in plasma. This study shows that D. cartdidum has a protective effect on iso- proterenol-induced Cardiac hypertrophy,