Measurement of human erythrocyte CAI and CAII in adult, newborn, and fetal blood.
OBJECTIVE
The aim of the present study was to determine the erythrocyte CAI and CAII concentrations in fetal blood over a wide gestational range, and compare levels to those found in neonates and adults.


METHODS
Human erythrocyte CAI and CAII concentrations were measured in fetal (n=38), neonatal (n=10) and adult (n=30) blood, using enzyme-linked immunosorbent assays (ELISA). For the measurement of CAII, a new ELISA method was developed.


CONCLUSIONS
The ELISA method was found to be simple, sensitive, economical, and precise. The normal mean levels of erythrocyte CAI and CAII in adults with standard deviation were 13.68 +/- 2.79, and 1.59 +/- 0.21 mg/g Hb, respectively. The corresponding values in cord blood obtained at delivery at 38-40 weeks gestation were 1.20 +/- 0.68 and 0.46 +/- 0.13 mg/g Hb. The mean CAI/CAII ratio in adults was 8.8 and, in newborns, it was 2.5. The normal mean fetal erythrocyte CAI concentration increased significantly with gestation from 39 microgram/g Hb at 20 weeks to 380 microgram/g Hb at 38 weeks of gestation. Similarly, the CAII concentration increased from 53 microgram/g Hb at 20 weeks to 120 microgram/g Hb at 38 weeks of gestation. The CAI to CAII ratio also increased with gestation from 0.9 at 20 weeks to 2.5 at 38 weeks.
Aliakbar
S
S
Molecular Biology and Biophysics Section, Division of Biomedical Sciences, King's College London, Strand, UK.
Brown
P R
PR
D000328:Adult; D002256:Carbonic Anhydrases / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000706:statistics & numerical data; D004912:Erythrocytes / Q000201:enzymology*; D005069:Evaluation Studies as Topic; D005260:Female; D005312:Fetal Blood / Q000201:enzymology*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D012016:Reference Values; D012680:Sensitivity and Specificity
D002256:Carbonic Anhydrases