克山病心肌超微结构立体学分析及线粒体琥珀酸脱氢酶活性观察

Objective To perform a spatial analysis of myocardium uhrastructure and the activity of mitochondrial succinate dehydrogenase in sub-acute Keshan disease. Methods Myocardium samples were collected from the cases with sub-acute Keshan disease and non-myocarditis(control), and their ultrastructure was observed under electron microscope. The density of mitochondrion volume and cristal membrane and its volume were measured by a point-counting method, while mitochondrion volume was estimated by water displacement method, succinate dehydrogenase activity of mitochondrion by iron-copper method in sub-acute Keshan disease and non-myocarditis cases. Results The volume ratio of mitochondrion to the cell on myoeardium [(47.79±6.20)%], the area ratio of mitochondrion to sarcoplasm [(55.06±6.50) %], mitochondrion to myofibrils [(1.43±0,41)%], mitochondrion section area[(0.78±0.15)μm2], and ratio of the lesion of cristal membrane area to the matrix area and mitochondrion volume[(67.14±13.96)%, (44.62±13.44)%]in sub-acute Keshan disease group were obviously higher than those in control [(33.20±7.62)%, (38.07±9.43)%, (0.71±0.33)%, (0.44±0.07)μm2, (14.11± 12.51)%, (9.34±11.28)%; t = 3.75,7.93,6.61,36.40,52.65,37.51, all P < 0.05]. The volume ratio of myofibrils to cell[(34.52±5.12)%]and the area ratio of cristae mitochondria to matrix[(32.43±14.42)%]in sub-acute Keshan disease group was obviously less than those in control [(48.51±4.30)%, (86.04±12.37)%; t = 9.85, 53.46, both P < 0.05)]. Succinate dehydrogenase activity was negative in sub-acute Keshan disease group. Conclusions Myocardium ultrastructure changes in sub-acute Keshan disease including the increase of volume and areas of mitochondria and the damage of the cristal membrane in mitochondria. Succinate dehydrogenase activity is decreased or even disappeared.

The spatial analysis of myocardium ultrastructure and observation of activity of mitochondrial enzymes