Developmental expression of cytochrome CYP26B1 (P450RAI-2) in human cephalic tissues.

Expression levels of cytochrome CYP26B1, which is involved in the specific all-trans-RA inactivation, were evaluated in human cephalic tissues at gestational days 57-110 and exhibited values approximately 10-fold higher than later gestational days 112-224 and adult tissues. CYP26B1 mRNA levels in the adult cerebellum were approximately 2-fold higher than in the adult whole brain tissue. Considered together, these data suggest a unique role for CYP26B1 during human brain development.