Soboll S, Bünger R
Hoppe Seylers Z Physiol Chem. 1981 Feb;362(2):125-32. doi: 10.1515/bchm2.1981.362.1.125.
Relationships between subcellular adenine nucleotides (ATP, ASP), heart function and oxidative myocardial metabolism were studied in the isolated working guinea pig heart. The heart preparations were stimulated by noradrenaline and utilized pyruvate alone or in combination with glucose as energy-providing substrates. Using density gradient centrifugation of lyophilized myocardial homogenates in non-aqueous media the following subcellular distribution of ATP and ADP, respectively, was obtained: The concentration of ATP in the cytosol was higher than in the mitochondria while the content of ADP was not different. The overall ATP/ADP ratio in the cytosol was more than 10-fold lower than the concentration ratio of free ATP and ADP in the cytosol as derived from the cytosolic creatine kinase equilibrium. Furthermore, the mitochondrial ATP/ADP ratio was much lower than the free cytosolic ATP/ADP ratio. The concentration term of the phosphorylation potential of ATP (RT in [ADP] x [Pi]/[ATP]) was thus higher in the cytosol than in the mitochondria. Myocardial function and substrate oxidation exhibited typical augmentations during infusion of 0.08 microM noradrenaline. However, increased heart performance and oxidative myocardial metabolism were not associated with major changes in the cytosolic ATP or ADP contents. On the other hand, the free ATP/ADP ratio and particularly the phosphorylation state of ATP, i.e. the ration [ATP]/[ADP] x [Pi], were decreased in the cytosol. In contrast, in the mitochondria adenine-nucleotide concentration ratios were not substantially changed under the same conditions. The results are compatible with an asymmetrical translocation of adenine nucleotides across the mitochondrial membrane in working hearts. The reciprocal relationship between rates of oxidative metabolism and free cytosolic ATP/ADP ratio indicates that mitochondrial respiration in the intact heart could be controlled by the phosphorylation state of the extramitochondrial ATP.
在离体工作的豚鼠心脏中研究了亚细胞腺嘌呤核苷酸（ATP、ADP）、心脏功能与心肌氧化代谢之间的关系。心脏标本用去甲肾上腺素刺激，并单独使用丙酮酸或丙酮酸与葡萄糖联合作为供能底物。通过在非水介质中对冻干心肌匀浆进行密度梯度离心，分别获得了ATP和ADP的以下亚细胞分布：胞质溶胶中ATP的浓度高于线粒体，而ADP的含量没有差异。胞质溶胶中总的ATP/ADP比值比根据胞质肌酸激酶平衡得出的胞质溶胶中游离ATP和ADP的浓度比值低10倍以上。此外，线粒体ATP/ADP比值远低于游离胞质溶胶ATP/ADP比值。因此，ATP磷酸化电位的浓度项（RT×[ADP]×[Pi]/[ATP]）在胞质溶胶中高于线粒体。在输注0.08μM去甲肾上腺素期间，心肌功能和底物氧化表现出典型的增强。然而，心脏性能的提高和心肌氧化代谢的增加与胞质溶胶中ATP或ADP含量的主要变化无关。另一方面，胞质溶胶中游离ATP/ADP比值，特别是ATP的磷酸化状态，即[ATP]/[ADP]×[Pi]比值降低。相反，在相同条件下，线粒体中腺嘌呤核苷酸浓度比值没有显著变化。这些结果与工作心脏中腺嘌呤核苷酸跨线粒体膜的不对称转运相一致。氧化代谢速率与游离胞质溶胶ATP/ADP比值之间的相互关系表明，完整心脏中的线粒体呼吸可能受线粒体外ATP磷酸化状态的控制。
