Basal plasma ACTH(1-39) concentrations are elevated in long-term @entity519 (LTH) fetal @entity742 . This study was designed to determine whether the expression of genes regulating @entity701 biosynthesis was altered after LTH. Pregnant ewes were maintained at high altitude (3,820 m) from day 30 of gestation to near term, when the animals were transported to the laboratory. Reduced @entity4095 was maintained by @entity1568 infusion through a maternal tracheal catheter. On days 137-141, fetal adrenal glands were collected from LTH and normoxic control fetuses. Real-time PCR was used to quantify mRNA for steroidogenic acute regulatory protein, 17alpha-hydroxylase ( @entity68165 ), 21-hydroxylase (CYP21), @entity165 side-chain cleavage ( @entity68166 ), @entity1816 dehydrogenase type II (HSD3B2), and the @entity56184 . We analyzed mRNA by slot-blot hybridization and also quantified mRNA for transcription factors necessary for adrenocortical development by quantitative real-time PCR: @entity68167 and @entity13419 , @entity509 congenital, critical region on the X chromosome (DAX-1). Protein was quantified by Western blot analysis. Adrenal mRNAs for @entity68165 , @entity68166 , and the @entity56184 were significantly reduced in LTH fetal @entity742 compared with levels shown in controls. Similarly, @entity68166 protein and @entity68165 protein were reduced in the LTH group. CYP21, steroidogenic acute regulatory protein, @entity68167 , and DAX-1 expressions were not altered in response to LTH. We conclude that expression of two key steroidogenic enzymes ( @entity68165 , @entity68166 ) regulating @entity701 biosynthesis and the @entity56184 is lower in response to LTH. This likely represents an adaptive response to LTH, to prevent excessive @entity701 production that would restrict fetal growth and potentially induce @entity3152 .

Long-term @entity519 represses the expression of key genes regulating XXXX biosynthesis in the near-term ovine fetus.

@entity68167 :: ('443464(Tax:9940)', 'Gene') :: ['steroidogenic factor 1', 'HSD3B2, steroidogenic factor 1'] @entity1568 :: ('MESH:D009584', 'Chemical') :: ['nitrogen'] @entity68165 :: ('105601846', 'Gene') :: ['CYP17'] @entity742 :: ('9940', 'Species') :: ['sheep'] @entity3152 :: ('MESH:D007752', 'Disease') :: ['preterm delivery'] @entity68166 :: ('100048994(Tax:9940)', 'Gene') :: ['CYP11A1'] @entity1816 :: ('CHEBI:36836', 'Chemical') :: ['3beta-hydroxysteroid'] @entity13419 :: ('MESH:C535601', 'Disease') :: ['dosage-sensitive sex reversal'] @entity509 :: ('MESH:C538429', 'Disease') :: ['adrenal hypoplasia'] @entity519 :: ('MESH:D000860', 'Disease') :: ['hypoxic'] @entity701 :: ('MESH:D006854', 'Chemical') :: ['cortisol'] @entity56184 :: ('443482(Tax:9940)', 'Gene') :: ['ACTH receptor'] @entity4095 :: ('MESH:C093415', 'Chemical') :: ['PO2'] @entity165 :: ('MESH:D002784', 'Chemical') :: ['cholesterol']
@entity701 :: (MESH:D006854,Chemical) :: ['cortisol']
