[Effects of hypoxia on myoglobin in cultured rat myocytes]

The effects of hyoxia and reoxygenation on myoglobin (Mb), cAMP, myocardial contractility and the effects of theophylline (an inhibitor of phosphodiesterase), procaine (an inhibitor of SR calcium release) on Mb expression were studied in cultured myocytes under hypoxic condition. Our results showed that hypoxia increased the Mb expression, but decreased cAMP and myocardial contractility. All these effects of hypoxia were recovered upon reoxygenation. The increase of Mb expression requires the participation of intracellular calcium and cAMP.