Abstract
This study was designed to evaluate the effect of hypoxia (N2) and reoxygenation (re-O2) on mitochondrial function (MF) in the newborn (NB) and adult (A) rabbit heart. The heart was isolated, arterially perfused with Krebs-Henseleit solution, and maintained at 27°C. After hypoxia or hypoxia and reoxygenation, the mitochondria was isolated and MF was determined by polarographic technique. In the oxygenated perfused muscle (control), state 3 respiration (QO2) and respiratory control index (RCI) in NB (QO2=128 ±6 nAO/min/mg protein; RCI=16.0 ± 0.8; n=8) were significantly (P<0.001) greater than the values in the A (QO2=86 ± 4; RCI= 9.2 ± 0.7; n=9). After 40 or 60 min N2, QO2 decreased significantly (P<0.01) to 78 ± 5% of control in the NB (n=10) and 67 ± 13% of control in the A (n=8). During reoxygenation following 40 min N2, QO2 was not significantly different from control in both the NB and A. Reoxygenation following 60 min N2, however, did not improve MF and QO2 in the NB (51 ± 6% of control) and A (59 ±6%) remained significantly (P<0.001) less than control. The changes in RCI were similar to QO2 in all groups. The ADP/O ratio was not significantly different from control in all groups. These data indicate that the depression in mitochondrial function is reversible after 40 min N2 but is irreversible after 60 min N2, and there was no difference between the NB and A hearts.
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Young, H., Shimizu, T., Nishioka, K. et al. 216 EFFECTS OF HYPOXIA AND REOXYGENATION ON MITOCHONDRIAL FUNCTION IN THE NEWBORN MYOCARDIUM. Pediatr Res 15 (Suppl 4), 475 (1981). https://doi.org/10.1203/00006450-198104001-00225
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DOI: https://doi.org/10.1203/00006450-198104001-00225