Effect of low altitude on glycolytic key enzymes in red blood cells

METHOD: The ATP level and the activities of hexokinase (HK), phosphofructokinase-1 (PFK-1) and pyruvate kinase (PK) in red blood cells (RBC) were measured in 50 school students 6-12 yr of age in the Jordan Valley (JV) which is the lowest region below sea level in the world (low altitude: 390 m below sea level, hyperoxic and with an average daily value of 796 mmHg barometric pressure) and in 50 school students of the same age group in Irbid region (normal altitude: 600 m above sea level and with an average daily value of 600 mmHg barometric pressure). The same parameters were measured also in 40 school students at sea level. RESULTS: A significant decrease in HK and PFK-1 activities and an increase in ATP level in the low altitude region, while no significant change in PK activity in JV-group when compared to Irbid and to the sea level control groups. Possible explanations will be discussed to interpret these observations.