LAUSR

Abstract The aim of this study was to investigate the influence of intermittent hypobaric hypoxia on the expression hypoxia adaptation proteins, namely hypoxia inducibla factor-1a (HIF-1a) and myoglobin (Mb). Twenty five male Sprague-Dawley rats were exposed to intermittent hypobaric hypoxia in a hypobaric chamber in Indonesian Air Force Institute of Aviation Medicine, for 49.5 minutes at various low pressure, 1 week interval for 4 times (day 1, 8, 15 and 22). HIF-1α and Mb protein were measured with ELISA. mRNA expression of Mb was measured with one step real time RT-PCR. HIF-1α protein levels increased after induction of hypobaric hypoxia and continues to decrease after induction of intermittent hypobaric hypoxia 3 times (ANOVA, p = 0.0437). mRNA expression and protein of Mb increased after induction of hypobaric hypoxia and continues to decrease after induction of intermittent hypobaric hypoxia 3 times (ANOVA, p = 0.0283; 0.0170), and both are strongly correlated (Pearson, r = 0.6307). The heart of rats adapted to intermittent hypoxia conditions by upregulation the expression of HIF-1a and myoglobin and then both return to normal level.