绿豆子叶线粒体发育过程中腺苷酸的变化及其对细胞能量代谢的影响

CHANGES OF ADENINE NUCLEOTIDE IN THE COURSE OF MITOCHONDRIAL DEVELOPMENT OF MUNG BEAN COTYLEDON AND THEIR EFFECT ON CELLULAR ENERGY STATUS

本文研究了绿豆子叶线粒体发育过程中腺苷酸能荷(AEC)的变化及其和细胞能量状态的关系。观察到吸胀2小时的绿豆子叶线粒体发育不完全,吸胀12小时线粒体内膜出现明显的内嵴。随着线粒体完整性的增加,H^+-ATPase 的活性明显增大,细胞的 ATP 水平也明显提高,AMP 水平下降,AEC 值剧增,但此时线粒体本身的腺苷酸水平及 AEC 值变化不大。经1×10^(-4)mol/1和5×10^(-4)mol/1 DNP 处理的子叶,细胞中 ATP 含量大大降低,AMP 增多,AEC 随之下降,而线粒体的腺苷酸及 AEC 仍然保持衡定,腺苷酸激酶(AK)的活性不但不受 DNP 的抑制,反比对照增加约50%。线粒体能量状态的维持可能受 AK 的调节。

The changes of adenine nucleotide and adenylate energy charge(AEC)during the deve- lopment of mitochondria in imbibed mung bean cotyledons and the relationship between these changes and cellular energy status were studied.After cotyledons were imbibed in water for two hours,mitochondrial cristae were not observed,but for 12 hours,they appeared obviously on the inner membrane.With the structural integrity of the mitochondria,the functional mi- tochondria were graduately shown.For instance,the activity of H^+-ATPase of cotyledons im- bibed for 24 hours was about twice higher than that of 2 hours.The ATP content and the AEC value in the cotyledons imbibed for 24 hours increased sharply and the AMP decreased,but these were not observed in the mitochondria of the cotyledons imbibed either for 24 hours or 2 hours.When the cotyledons were imbibed in 1×10^(-4)mol/l or 5×10^(-4)mol/l DNP solution for 24 hours,the ATP and the AEC in the cells exhibited a rapid decrease,but in the mitochon- dria they remained canstant.In the same DNP solution with cotyledons for 24 hours,the acti- vity of mitochondrial adenylate kinase(AK)not only was not decreased but also increased by about 50% over the control.This result shows that the energy equilibration in the mitochondria seems likely to be regulated by adenylate kinase locating between inner and out membranes of the mitochondria.