PCPA对不同月龄大鼠额叶皮层线粒体超微结构、膜电位和ATP酶的影响

Effects of PCPA on mitochondrial ultrastructure,membrane potential and ATPase in frontal cortex of rats at different ages

目的探讨对氯苯丙氨酸(PCPA)对不同月龄大鼠额叶皮层线粒体形态和功能的影响。方法取3~9月龄大鼠进行造模,分别观察PCPA腹腔注射3d后额叶皮层线粒体形态功能的改变;采用超活染色观察线粒体的数目和活性,透射电镜观察线粒体超微结构变化,同时采用荧光探针JC-1检测线粒体膜电位改变和WST-1法测定线粒体ATP酶含量。结果①与正常组相比,各月龄大鼠经连续注射PCPA 3d后,其额叶皮层线粒体的数量明显减少;同时在各月龄正常大鼠中,其额叶皮层线粒体的数量随大鼠月龄的增加而呈现出先增加后减少的趋势。②各月龄大鼠注射PCPA 3d后,额叶皮层线粒体出现肿胀、嵴断裂甚至空泡化,其中以6月龄最为明显。③各月龄大鼠造模后额叶皮层线粒体的膜电位与造模前相比均显著下降;各月龄正常组大鼠线粒体膜电位随着月龄的增加出现先增加后下降的趋势,且6月龄正常组大鼠与其他月龄正常组大鼠相比均有统计学意义(P<0.05);各月龄模型组大鼠也相应地出现上述变化。④随着月龄的增加,各月龄正常组大鼠和模型组大鼠额叶皮层线粒体Na^+-K^+-ATP和Ca^2+-Mg^2+-ATP酶含量均出现先增加后减少的趋势,且6月龄与其他月龄相比也具有统计学意义(P<0.05)。结论①3~9月龄大鼠连续注射PCPA 3天后其额叶皮层线粒体超微结构、膜电位、Na^+-K^+-ATP和Ca^2+-Mg^2+-ATP酶含量改变以6月龄为最;②PCPA致大鼠失眠可能与额叶皮层线粒体超微结构改变、膜电位和Na^+-K^+-ATP和Ca^2+-Mg^2+-ATP酶含量下降有关。

Objective To investigate the effects of PCPA on mitochondria morphology and function in frontal cortex of rats of different ages. Methods Rats at 3 , 4, 5, 6, 7, 8 , and 9 months old were used to observe the changes of mitochondrial morphological function in frontal cortex after 3 days of PCPA intraperitoneal injection.The number and activity of mitochondria were observed by ultra-staining.The ultrastructural changes of mitochondria were observed by transmission electron microscopy. The mitochondrial membrane potential was detected by fluorescent probe JC-1 and the mitochondrial ATPase content was determined by WST-1 method.Results①Compared with the normal group, the number of mitochondria in the frontal cortex was significantly reduced in the rats of each month after continuous injection of PCPA for 3 days. At the same time, the number of mitochondria in the frontal cortex of normal rats in each month was showed a tendency to increase first and then decrease with the increase of the age of the rats.② After 3 days of PCPA injection in rats of each month , the mitochondria of the frontal cortex showed swelling , sputum rupture and even vacuolization , which was most obvious at 6-month age.③The membrane potential of mitochondria in the frontal cortex of the model group at each age was significantly decreased compared with the normal group. The mitochondrial membrane potential of normal rats at each age increased first and then decreased with the increase of age. The mitochondrial membrane potential of the normal age group of 6-month age rats were statistically significant compared with other months age of the normal groups (P<0.05);The similar changes occurred in the rats of each month model group.④With the increase of age, the contents of mitochondrial Na^+-K^+-ATP and Ca^2+-Mg^2+- ATPase in the frontal cortex of rats , including the normal group and the model group , increased first and then decreased, and 6-month age was also statistically significant compared with other months age(P<0.05). Conclusion ①The changes of mitochondrial ultrastructure , membrane potential, Na^+-K^+-ATP and Ca^2+-Mg^2+-ATPase in the frontal cortex of rats aged 3~ 9 months were the most in 6 months.② PCPA-induced insomnia in rats may be related to the degeneration of mitochondrial ultrastructure, the decrease of membrane potential and Na^+-K^+-ATP and Ca^2+-Mg^2+-ATPase levels in the frontal cortex.