RED-BLOOD-CELL GLUCOSE-METABOLISM IN TRISOMY-10P - POSSIBLE ROLE OF HEXOKINASE IN THE ERYTHROCYTE

  • 1 January 1983
    • journal article
    • research article
    • Vol. 61  (5) , 915-919
Abstract
Red blood cell glucose metabolism was investigated in a boy with de novo trisomy 10p. According to previous evidence, when assigning hexokinase gene locus in the 10p11 .fwdarw. pter region, a triplex dosage effect of hexokinase activity (HK) was found, while all the other erythrocyte glycolytic enzymes were in the normal values range. Red blood cell glucose utilization was 2.87 .mu.mol/h per ml RBC as comapred to 1.43 in normal controls; the rate of glucose metabolized through the hexose monophosphate shunt (HMPS) was unchanged. Glucose-6-phosphate, fructose-6-phosphate, fructose-1,6-diphosphate, and dihydroxyacetone phosphate increased with respect to normal controls, while normal levels of 3-phosphoglycerate, 2-phosphoglycerate, phosphoenolpyruvate and ATP were found. The HK activity increased in all the red blood cell fractions obtained by density gradient ultracentrifugation. However, a small difference in the distribution of cells through the gradient was evident. In the red blood cells of patients with trisomy 10p, an increased level of HK apparently leads to higher concentrations of glucose-6-phosphate and to a faster glucose utilization in the Embden-Meyerhof pathway, while the HMPS rate is unchanged.