Sex steroid metabolism in the tibial growth plate of the rat.
To assess whether growth plate-specific production of sex steroids is possible, we have surveyed the presence of several key-enzymes involved in androgen and estrogen metabolism in the tibial growth plate of female and male rats during development. Using in situ hybridization, mRNAs of aromatase p450, type I and II 17beta-hydroxysteroid dehydrogenase (HSD), steroid sulfatase (STS), and 5alpha-reductase were detected in proliferating and hypertrophic chondrocytes of the growth plate. The former three were strongly up-regulated around sexual maturation (7 wk), whereas the latter two were expressed at a relatively constant level during development. These data were supported by measuring aromatase, type I 17beta-HSD, and STS enzyme activities in chondrocytes collected from tibial growth plates at 1 and 7 wk of age. Of the enzymes studied, there were minor differences between the sexes in aromatase and 5alpha-reductase expression only. In conclusion, our findings clearly indicate the presence of various enzymes involved in sex steroid metabolism in the tibial growth plate, especially in sexually maturing rats, a timepoint at which sex steroids have major effects on longitudinal growth. Our data suggest that intracrinology in the rat growth plate can occur and may be a major source of local sex steroid delivery.
Van Der Eerden
B C J
BC
Department of Pediatrics, Leiden University Medical Center, The Netherlands.
Van De Ven
J
J
Lowik
C W G M
CW
Wit
J M
JM
Karperien
M
M
D015067:17-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism; D000375:Aging / Q000378:metabolism; D000818:Animals; D001141:Aromatase / Q000235:genetics / Q000378:metabolism; D001192:Arylsulfatases / Q000235:genetics / Q000378:metabolism; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism*; D006132:Growth Plate / Q000378:metabolism*; D017403:In Situ Hybridization; D008297:Male; D012333:RNA, Messenger; D051381:Rats; D017208:Rats, Wistar; D043266:Steryl-Sulfatase; D013977:Tibia / Q000378:metabolism*
D012739:Gonadal Steroid Hormones; D012333:RNA, Messenger; D015067:17-Hydroxysteroid Dehydrogenases; C044256:3 (or 17)-beta-hydroxysteroid dehydrogenase; D001141:Aromatase; D001192:Arylsulfatases; D043266:Steryl-Sulfatase