[Changes in the energetics of muscle contraction as a result of hyperoxia].
Using a highly sensitive thermometric method (1 X 10(-5) degrees C/mm), it was found that the heat production of a single isometric contraction of an isolated diaphragm of the rats exposed to 99% O2 at normal pressure for 3 and 6 hrs significantly differed from the norm: after 3 hr hyperoxygenation muscle heat production increased almost three-fold, and after 6 hr hyperoxygenation it decreased almost two-fold. The increase is regarded as a result of oxygen-potentiated increase of energy expenditures involved in a contraction and of a decrease of the performance of muscle contraction. The decrease is considered as a consequence of the primary in economical energy expenditures by an intensively working muscle represented by the diaphragm and of a reduced viability of the muscle preparation incubated in vitro.
D000818:Animals; D001833:Body Temperature Regulation; D003964:Diaphragm / Q000502:physiology; D005260:Female; D066298:In Vitro Techniques; D007537:Isometric Contraction; D009132:Muscles / Q000502:physiology*; D010100:Oxygen; D051381:Rats; D013997:Time Factors
D010100:Oxygen
Izmenenie énergetiki myshechnogo sokrashcheniia v rezul'tate giperoksii.