Comparison of sex-steroid synthesis between neonatal and adult rat hippocampus.
Sex-steroid synthesis in the hippocampus had been thought to be much more active at the neonatal stage than at the adult stage. However, the detailed comparison between these two stages had not been demonstrated yet. Here we performed the comparison about the mRNA level of steroidogenic enzymes and the rate of steroid metabolism between these two stages of the hippocampus. The relative expression level of P450(17alpha), 17beta- or 3beta-hydroxysteroid dehydrogenase, or P450arom was approximately 1.3-1.5-fold higher at the neonatal than at the adult stage. The rate of sex-steroid metabolism (from dehydroepiandrosterone to estradiol) was 2-7-fold (depending on different steps) more rapid at the neonatal than at the adult stage. Taken together, neonatal steroidogenesis is moderately more active than adult steroidogenesis.
Department of Biophysics and Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan.
Shimpei
S
Higo
Yasushi
Y
Hojo
Hirotaka
H
Ishii
Toshihiro
T
Kominami
Kohei
K
Nakajima
Donald
D
Poirier
Tetsuya
T
Kimoto
Suguru
S
Kawato
D000367:Age Factors; D000818:Animals; D012739:Gonadal Steroid Hormones / Q000096:biosynthesis*; D006624:Hippocampus / Q000201:enzymology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013250:Steroid Hydroxylases / Q000378:metabolism*
D012739:Gonadal Steroid Hormones; D013250:Steroid Hydroxylases