Chen L, Tian X, Song L
Cardiovascular Institute, Chinese Academy of Medical Sciences, Beijing.
Chin Med J (Engl). 1995 May;108(5):361-6.
A comparative study of the biochemical and biophysical characteristics of myocardial mitochondria was conducted in 16-weeks-old male stroke-prone spontaneously hypertensive rats (SHRsp) and normotensive Wistar-Kyoto control rats (WKY) (n = 6-12). Cardiac and ventricular weights of SHRsp were significantly higher than those of the WKY group. The average amounts of mitochondria (Mit) and sarcoplasmic reticulum (SR) proteins isolated from the ventricle of SHRsp were 37% and 25% greater, respectively, when compared with those of WKY. Mit cytochrome c oxidase activities (mumol/min/mg) were 4.63 +/- 0.71 for SHRsp and 5.55 +/- 0.50 for WKY myocardium (mean +/- s), so that the activity of the former was significantly reduced by 17% (P < 0.01). Mit Ca2+, Mg(2+)-ATPase activity (mumol/min/mg) of SHRsp was 24% lower than that of WKY myocardium (P < 0.01). The fluorescence polarization of myocardial Mit membrane labelled with DPH (1, 6-diphenyl-1, 3, 5-hexatriene) in hypertensive rats was not different from that in control rats. The spectra of intrinsic protein fluorescence in 300-380 nm at an excitation wavelength of 290 nm were also identical in the Mit or SR between SHRsp and WKY myocardium. An ultrastructural analysis showed that there were more new-born Mit with smaller volumes and an increased number of isolated Mit in vitro from SHRsp myocardium, while there were larger Mit volumes isolated from WKY myocardium. These results demonstrated the disorder of mitochondrial energy metabolism in hypertrophied myocardium from SHRsp, which may be involved in the abnormality of myocardial calcium metabolism.
对16周龄雄性易中风自发性高血压大鼠（SHRsp）和血压正常的Wistar-Kyoto对照大鼠（WKY）（n = 6 - 12）的心肌线粒体生化和生物物理特性进行了比较研究。SHRsp的心脏和心室重量显著高于WKY组。与WKY相比，从SHRsp心室分离出的线粒体（Mit）和肌浆网（SR）蛋白的平均量分别高出37%和25%。SHRsp心肌的Mit细胞色素c氧化酶活性（μmol/min/mg）为4.63±0.71，WKY心肌为5.55±0.50（平均值±标准差），因此前者的活性显著降低了17%（P < 0.01）。SHRsp的Mit Ca2 +、Mg(2 +)-ATP酶活性（μmol/min/mg）比WKY心肌低24%（P < 0.01）。用DPH（1,6 - 二苯基 - 1,3,5 - 己三烯）标记的高血压大鼠心肌Mit膜的荧光偏振与对照大鼠无异。在290 nm激发波长下，300 - 380 nm处的固有蛋白荧光光谱在SHRsp和WKY心肌的Mit或SR中也相同。超微结构分析表明，SHRsp心肌中有更多体积较小的新生Mit，体外分离的Mit数量增加，而从WKY心肌中分离出的Mit体积较大。这些结果表明SHRsp肥厚心肌中线粒体能量代谢紊乱，这可能与心肌钙代谢异常有关。
