Developmental and glucocorticoid regulation of pituitary 11 beta-hydroxysteroid dehydrogenase 1 gene expression in the ovine fetus and lamb.
To examine the role of 11 beta-hydroxysteroid dehydrogenase 1 (11 beta-HSD1) in the control of glucocorticoid actions in the ovine pituitary during development, we have sought developmental changes in the distribution and the level of 11 beta-HSD1 mRNA by in situ hybridization. In the pars distalis, 11 beta-HSD1 mRNA was present by day 60; its amount did not change significantly until term (days 145-147) when it increased dramatically. The level of 11 beta-HSD1 mRNA increased further during the postnatal period. In contrast, 11 beta-HSD1 mRNA in the pars intermedia was not detectable until day 135; it increased in amount at days 140-143, but did not change significantly thereafter through to adulthood. We have also measured levels of both dehydrogenase and reductase activities of 11 beta-HSD1 in the pars distalis of fetal sheep at day 140 and term, and of postnatal sheep at 1-2 months of age, to determine whether changes in 11 beta-HSD1 mRNA are reflected in the levels of enzyme activities. There were progressive increases in both dehydrogenase and reductase activities from day 140 to 1-2 months postnatally, although dehydrogenase activity was consistently higher than reductase activity. Finally, we have determined the effect of short-term intrafetal cortisol infusion (5 micrograms/min for 12 h) on levels of pituitary 11 beta-HSD1 mRNA by in situ hybridization. There was no effect of cortisol infusion on 11 beta-HSD1 mRNA expression.(ABSTRACT TRUNCATED AT 250 WORDS)
Yang
K
K
Department of Obstetrics and Gynecology, University of Western Ontario, Lawson Research Institute, St Joseph's Health Centre, London, Canada.
Matthews
S G
SG
Challis
J R
JR
D042842:11-beta-Hydroxysteroid Dehydrogenases; D000818:Animals; D001483:Base Sequence; D005260:Female; D005333:Fetus / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006854:Hydrocortisone / Q000494:pharmacology; D006913:Hydroxysteroid Dehydrogenases / Q000235:genetics*; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes / Q000235:genetics; D010902:Pituitary Gland / Q000196:embryology / Q000201:enzymology* / Q000254:growth & development; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012756:Sheep
D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases; D006854:Hydrocortisone