[Ultrastructural rearrangements in skeletal muscles of different functional specialization during deep hypothermia]

During various periods of deep hypothermia and after warming in the rat muscle fibers of the diaphragm and of m. spinotrapezius essential structural changes take place. The destructive changes affect the myofibrillar and mitochondrial apparatuses and are mostly manifested during return out of the hypothermal state. Essential changes take place in quantitative characteristics of the sarcoplasmic reticulum, as well as in glycogen contents. Peculiar structural reactions of the respiratory and locomotor muscles are noted; they are determined by their different role in thermogenetic processes.