The aim of our study was to determine whether the impairment of Na+/K+ pump is detectable in erythrocytes during hypoxia and reoxygenation. Acute asphyxia was induced in 10 newborn piglets for 1 h by bilateral pneumothorax. The Na+/K+-ATPase activity, Na+, K+ and ATP content of RBCs were determined in baseline condition (p(a)O2: 60.4 ± 9.3 mmHg), at the end of the hypoxic period (1 h) (p(a)O2: 30.2 ± 10.3 mmHg), then hourly during the reoxygenation phase (2, 3, 4 h) (p(a)O2: 54.8 ± 9.0, 56.1 ± 8.7, 57.2 ± 9.6 mmHg). The Na+/K+-ATPase activity was constant during the first 3 h. However, it decreased at 4 h (676 ± 168 versus baseline 833 ± 141 U, p < 0.05). The highest ATP content was measured also at this point (4.32 ± 0.57 versus baseline 3.27 ± 0.45 mmol/l RBC, p < 0.01). The Na+ content was lower at 1 and 2 h (14.0 ± 1.8; 13.8 ± 1.2 versus baseline 15.7 ± 1.2 mmol/100 g Hb, p < 0.05), but later it became normal. Plasma monovalent cationic levels and intracellular K+ content did not alter during the experiment. Our results indicate that the deterioration of enzyme activity occurs within the same time-frame that previously described morphological alterations in brain tissue develop, so the RBC Na+/K+-ATPase activity might reflect the progress of posthypoxial brain damage.
- Na/K-ATPase activity
- Newborn piglet
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Developmental Biology