Erythrocyte enzyme activities in cord blood of extremely low-birth-weight infants.
To investigate the features of erythrocyte metabolism in extremely immature infants, we assayed 21 enzyme activities and glutathione level in cord erythrocytes from 28 extremely low-birth-weight infants (ELBWI; defined as birth weight <1,000 g). The results were compared with those from normal adults and non-neonatal reticulocyte-rich controls. Statistical analysis revealed that activities of six enzymes (glucosephosphate isomerase, phosphoglycerate kinase, monophosphoglycerate mutase, enolase, glucose-6-phosphate dehydrogenase (G6PD), and glutathione reductase) were significantly higher, and those of eight other enzymes (phosphofructokinase, 6-phosphogluconate dehydrogenase (6PGD), glutathione peroxidase, adenylate kinase, adenosine deaminase, acetylcholinesterase, NADH methemoglobin reductase, and catalase) were lower in ELBWI taking their marked reticulocytosis into consideration. The 6PGD/G6PD ratio, which is consistently unchanged under various physiological and pathological conditions, was markedly reduced in ELBWI. Our results support the previous reports that neonatal erythrocytes have a unique metabolic pattern which is different from that of adult erythrocytes, and also suggest that the 6PGD/G6PD ratio might be an index for the developmental immaturity of fetal erythrocytes. This is the first report describing the pattern of erythrocyte enzyme activities in ELBWI.
Miyazono
Y
Y
Department of Neonatology, Ibaraki Children's Hospital, Mito, Japan.
Hirono
A
A
Miyamoto
Y
Y
Miwa
S
S
D000110:Acetylcholinesterase / Q000097:blood; D000243:Adenosine Deaminase / Q000097:blood; D000263:Adenylate Kinase / Q000097:blood; D000328:Adult; D001724:Birth Weight; D002374:Catalase / Q000097:blood; D042966:Cytochrome-B(5) Reductase / Q000097:blood; D004912:Erythrocytes / Q000201:enzymology*; D005312:Fetal Blood / Q000201:enzymology*; D005956:Glucose-6-Phosphate Isomerase / Q000097:blood; D005954:Glucosephosphate Dehydrogenase / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D005980:Glutathione Reductase / Q000097:blood; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight / Q000097:blood*; D010734:Phosphogluconate Dehydrogenase / Q000097:blood; D012016:Reference Values; D017701:Reticulocyte Count; D012156:Reticulocytes / Q000201:enzymology*
D010734:Phosphogluconate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D002374:Catalase; D005979:Glutathione Peroxidase; D042966:Cytochrome-B(5) Reductase; D005980:Glutathione Reductase; D000263:Adenylate Kinase; D000110:Acetylcholinesterase; D000243:Adenosine Deaminase; D005956:Glucose-6-Phosphate Isomerase