Myoglobin and mitochondria: oxymyoglobin interacts with mitochondrial membrane during deoxygenation.

The rates of oxygen uptake by rat liver mitochondria (MC) (native coupled, freshly frozen, and uncoupled by FCCP) have been measured polarographically in the absence (V(0)) or presence (V(1)) of 0.11-0.25 mM sperm whale MbO2.

[Myoglobin and mitochondria: kinetics of oxymyoglobin deoxygenation in mitochondria suspension].

The kinetics of whale MbO2 deoxygenation was studied spectrophotometrically in the presence of breathing rat mitochondria under conditions when mitochondria were separated from the protein solution by a semipermeable film capable to transfer only low-molecular-weight compounds and directly in the solution of MbO2 with mitochondria (incubation medium: 15-35 mM succinate, 150 mM sucrose, 100 mM KCl, 0.5 mM EGTA, 5 mM KH2PO4, 10 mM MOPS, pH 7.4).

Myoglobin content in skeletal muscles of hibernating ground squirrels rises in autumn and winter.

The content of myoglobin (Mb) in skeletal muscles of Arctic Yakutian ground squirrel (Citellus undulatus Pallas) was measured in the active euthermic summer and prehibernating autumn animals as well as in hibernating and awake animals in winter. The myoglobin content in winter, irrespective of the state of the animal, was found to be about three times higher than in summer. The content of myoglobin in autumn was also two-fold increased compared to summer, suggesting that high myoglobin level is necessary for hibernation.

[The myoglobin level in skeletal muscles of the hibernating Iakutiia ground squirrel Citellus undulatus].

Many characteristics of the ground squirrel metmyoglobin (Mb) were found to be similar to those of the pig and different from the whale ones. The Mb content in winter time was 2.5-3.