Evidence of a steroidogenic enzyme gene dose effect on adrenal gene expression in hereditary rabbit congenital adrenal hyperplasia.

We previously reported the gene deletion encoding cytochrome P-450 cholesterol side-chain cleavage enzyme (P-450SCC, resulting in complete elimination of the adrenal gene expression and causing congenital adrenal hyperplasia in the rabbit. Using the rabbit congenital adrenal hyperplasia model, we investigated the wild type (wt) P-450SCC gene dose effect on gene expression in three P-450SCC genotype animals [wt/wt, wt/mutant (mt), mt/mt] identified by Southern blot analysis. Northern blots using a rabbit P-450SCC cDNA probe revealed no detectable P-450SCC mRNA in individual adrenals of animals with congenital adrenal hyperplasia (mt/mt) and approximately half or slightly less than half the levels of the mRNA in the pooled adrenals of five heterozygous (wt/mt) newborn animals compared with the mRNA levels in the pooled adrenals of five homozygous normal (wt/wt) newborn animals. Identical P-450SCC mRNA levels were found individual adrenals of adult animals with regard to the P-450SCC genotype, although at a higher expression level than in the newborn animals of the same genotype. Control Northern blots using human CPY21-B cDNA and cytoplasmic actin cDNA probes confirmed the accuracy and integrity of RNA. Western immunoblotting using anti-ovine P-450SCC antibody revealed decreased P-450SCC protein in the adrenals of wt/mt animals at approximately half the level of the P-450SCC protein in the adrenals of the wt/wt animals. Baseline and ACTH-stimulated serum corticosterone (B) levels in vivo were similar between the age-matched wt/mt and wt/wt animals, whereas ACTH-stimulated B levels in adult animals were higher than those in the newborn animals irrespective of P-450SCC genotype.(ABSTRACT TRUNCATED AT 250 WORDS)

3 alpha-Androstanediol glucuronide in premature and normal pubarche.

To investigate the role of adrenal androgens in 3 alpha-androstanediol glucuronide (3AG) production in childhood, we compared serum 3AG and androgen levels [dehydroepiandrosterone (DHEA), DHEA sulfate (DS), androstenedione (delta 4-A), and testosterone (T)] in 32 children with premature pubarche due to idiopathic premature adrenarche (IPA; n = 26), partial 21-hydroxylase deficiency (n = 2), or 3 beta-hydroxysteroid dehydrogenase deficiency (n = 4) with those in 36 normal prepubertal (18 males and 18 females) and 22 normal pubertal Tanner II-III subjects (10 males and 12 females). Serum 3AG (2.7 +/- 2.0 nmol/L) and all androgen concentrations in children with IPA were significantly higher (P less than 0.05-0.001) than those in normal prepubertal children (3AG, 0.8 +/- 0.5 nmol/L). Serum 3AG and androgen levels, except T, in all children with premature pubarche due to 21-hydroxylase deficiency or 3 beta-hydroxysteroid dehydrogenase deficiency were higher than those in the normal prepubertal children. Serum 3AG and all androgen levels in normal Tanner II-III male (3AG, 3.8 +/- 1.7 nmol/L) or female (3AG, 1.74 +/- 0.52 nmol/L) subjects were also significantly higher (P less than 0.05-0.001) than those in prepubertal children. Serum 3AG, DHEA, DS, and delta 4-A levels in children with IPA were similar to those in normal Tanner II-III females or males, but serum T in children with IPA (0.37 +/- 0.2 nmol/L) was significantly lower (P less than 0.05-0.001) than that in normal pubertal females (0.71 +/- 0.37 nmol/L) or males (4.5 +/- 2.6 nmol/L). In the combined group (n = 88), 3AG levels correlated better with serum DS (r = 0.7), DHEA (r = 0.6), and delta 4-A (r = 0.52), than with T (r = 0.31) levels. These data suggest that the weak adrenal androgens DS, DHEA, and delta 4-A contribute substantially to 3AG production in premature and normal pubarche.