Maturation of AFMU excretion in infants.
The maturation of the N-acetyltransferase-dependent AFMU production from caffeine was studied during infancy. The group of children (N = 14) consisted of 4 premature newborn infants and ten 1-19 month-old infants who received caffeine citrate solution for the treatment and prevention of apnea. Caffeine, AFMU, 1X and 9 other metabolites were measured in urine using HPLC. The AFMU/1X ratio did not vary significantly in this population with increasing age. In one of the infants serially studied, the AFMU/1X ratio increased dramatically between 6 and 12 months of age. This observation suggests that the maturation of N-acetyltransferase activity is not completed before 1 year of age implying that acetylator status cannot reliably be determined before that age. Patients studied before 1 year of age whose AFMU/1X ratio was below 0.4 may be either true slow acetylators or still immature fast acetylators.
Pons
G
G
Département de Pharmacologie Périnatale et Pédiatrique, Hôpital Saint-Vincent-de-Paul, Paris, France.
Rey
E
E
Carrier
O
O
Richard
M O
MO
Moran
C
C
Badoual
J
J
Olive
G
G
D000107:Acetylation; D002110:Caffeine; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007202:Indicators and Reagents; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000652:urine*; D010641:Phenotype; D014498:Uracil / Q000031:analogs & derivatives* / Q000652:urine
D007202:Indicators and Reagents; D002110:Caffeine; D014498:Uracil; C036692:5-acetylamino-6-formylamino-3-methyluracil