マンガンの生体影響に関する研究 第4編 マンガン及びバナジウムのラット肝ミトコンドリアの酸化的リン酸化反応に及ぼす複合作用

Cooperative effects of Mn(2+) and V(5+) on the energy transfer reaction of rat liver mitochondria were investigated. Mn(2+) (0.10-0.05mM) increased State 4 resperation and decreased State 3 respiration, indicating an uncoupling action on the mitochondria. V(5+) alone at the concentration of 0.1-0.8 mM had no noticeable effect on mitochondrial respiration. In the presence of V(5+), Mn decreased both State 3 and State 4 respiration. The degree of the inhibition was extreme in State 3 respiration at a low concentration of Mn. The change from the accelation of State 4 respiration by Mn(2+) alone to its inhibition by Mn(2+) and V(5+) suggests an incease of cleteriovation in mitochondrial function by the cooperative action of Mn(2+) and V(5+). Cooperative effects of Mn(2+) and Mg(2+) on the energy transfer reaction have been described. In the presence of Mg(2+), the uncoupling action of Mn(2+) was not observed, suggesting that the injurious effect of Mn(2+) on mitochondrial membrane was depressed by Mg(2+). However, phosphorylation activity was more strongly inhibited with Mn(2+) and Mg(2+) together than with Mn(2+) alone.