Non invasive in vivo study of the maturation of CYP IIIA in neonates and infants.
OBJECTIVE
Cytochrome P450 III (CYP III) has previously been demonstrated in vitro in fetal liver.


METHODS
A study was performed in 7 premature, 13 term neonates and 30 infants to assess whether or not maturation had any influence on CYP IIIA activity in children from birth to 1 year of age. A simple non invasive procedure was used (6 beta OHF/FF concentration ratio in a morning spot urine sample).


RESULTS
The 6 beta OHF/FF ratio was 7.2, 7.9 and 5.0 in premature and term neonates and infants, respectively. CYP IIIA activity is present at birth, with a 6 beta OHF/FF ratio comparable to adults. Its activity seemed lower in infants. This might be due to the decrease in CYP IIIA7 activity during maturation after birth, which might be more rapid than the increase in CYP IIIA3/4 activity.
Vauzelle-Kervroedan
F
F
Département de Pharmacologie Clinique Périnatale et Pediatrique, Hôpital Saint-Vincent de Paul, Paris, France.
Rey
E
E
Pariente-Khayat
A
A
Bienvenu
T
T
Badoual
J
J
Olive
G
G
Pons
G
G
D000367:Age Factors; D001189:Aryl Hydrocarbon Hydroxylases; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism* / Q000652:urine; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008099:Liver / Q000201:enzymology*; D008297:Male; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism* / Q000652:urine; D012044:Regression Analysis
D003577:Cytochrome P-450 Enzyme System; D001189:Aryl Hydrocarbon Hydroxylases; D051544:Cytochrome P-450 CYP3A; D010089:Oxidoreductases, N-Demethylating