The effects of alpha-methyldopa on cardiac hypertrophy in spontaneously hypertensive rats: ultrastructural, stereological, and morphometric analysis.
The effects of alpha-methyldopa on cardiac hypertrophy in spontaneously hypertensive rats: ultrastructural, stereological, and morphometric analysis.
复制标题
α-甲基多巴对自发性高血压大鼠心脏肥大的影响：超微结构、体视学和形态测量分析。
DOI：
10.1093/cvr/13.3.173
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发表时间：
1979
影响因子：
10.8
通讯作者：
Steven C. Anderson
中科院分区：
文献类型：
--
作者：
R. Tomanek;James W. Davis;Steven C. Anderson
本研究探讨了α-甲基多巴对心肌细胞及其微血管床的作用。自发性高血压大鼠（SHR）在4周龄时开始给药。从灌注固定的心脏的16周龄大鼠的组织标本进行了研究，电子显微镜和数据获得的体视学和形态计量学方法。
SHR的心内膜下和心外膜下心肌细胞肥大，毛细血管密度明显下降。尽管α-甲基多巴（在本研究中使用的方案中）未能显著降低SHR的血压，但药物治疗大鼠（T-SHR）的心脏重量值处于高正常范围。构成心外膜的心脏细胞大小与血压正常的动物相似，而构成心内膜的心脏细胞则轻度肥大。虽然SHR的肥大与线粒体体积的细胞部分的减少和体积比的减少有关：线粒体/肌原纤维，但在T-SHR中，这些参数即使在轻度肥大的亚内皮细胞区域的细胞中也是正常的。增强折叠的闰盘，虽然变量，被认为是最常见的心外膜下和subendocardium的T-SHR。
这些数据表明，α-甲基多巴可以预防或改变肥大，而不会显着改变血压。虽然某些细胞参数，即线粒体和肌原纤维的体积分数，可以通过这种干预来正常化，但增强了闰盘的折叠。
This study examined the role of α-methyldopa on the myocardial cell (cardiocyte) and its microvascular bed. Spontaneously hypertensive rats (SHR) were administered the drug commencing at 4 weeks of age. Tissue specimens from perfused-fixed hearts of 16 week-old rats were studied by electron microscopy and data obtained using stereological and morphometric methods.
In both the subendocardium and subepicardium of SHR cardiocytes were hypertrophic and a significant drop in capillary density was evident. In spite of the failure of α-methyldopa (in the protocol used in this study) to significantly reduce blood pressure in SHR, heart weight values of the drug-treated rats (T-SHR) were in the high normal range. Cardiocytes comprising the subepicardium were similar in size to those of normotensive animals, while those comprising the subendocardium were mildly hypertrophic. While hypertrophy in the SHR was associated with a decrease in the cellular fraction of mitochondrial volume and a decrease in the volume ratio: mitochondria/myofibrils, in T-SHR these parameters were normal even in cells from the mildly hypertrophic sub- endocardial region. Enhanced folding of the intercalated disc, though variable, was found to be most common in both the subepicardium and subendocardium of T-SHR.
These data suggest that α-methyldopa may prevent or modify hypertrophy without significantly altering blood pressure. While certain cellular parameters, ie, fractional volumes of mitochondria and myofibrils, may be normalised by this intervention, enhanced folding of the intercalated disc is accentuated.