Pregnane hydroxylases

Joannou GE (1981) Identification of 15/5-hydroxylated C21 Steroids in the neo-natal period the role of 3a,15/),17a-trihydroxy-5/ -pregnan-20-one in the perinatal diagnosis of congenital adrenal hyperplasia (CAH) due to a 21-hydroxylase deficiency. J Steroid Biochem 14 901-912... 

Li, T. and Chiang, J. Y. (2005) Mechanism of rifampicin and pregnane X receptor inhibition of human cholesterol 7 alpha-hydroxylase gene transcription. Am. J. Physiol. Gastrointest. Liver Physiol. 288, G74-G84. 

Li JS, Li Y, Son C, Brodie AM (1996) Synthesis and evaluation of pregnane derivatives as inhibitors of human testicular Ha-hydroxylase/Cjyjo-... 

Yoshimoto FK, Desilets MC, Auchus RJ (2012) Synthesis of halogenated pregnanes, mechanistic probes of steroid hydroxylases CYP17A1 and CYP21A2. J Steroid Biochem Mol Biol 128 38-50... 

Although there is a good correlation between the severity of salt loss and the degree of impairment of 21-hydroxylase activity, the salt loss effect has sometimes been claimed to result from the elaboration of salt-losing hormones rather than from interference with aldosterone synthesis. 3a,16a-Dihydroxy-5a(or 5j8)-pregnan-20-one has been incriminated, but the salt-losing effects of these compounds have not been established in humans. 

The first glimpse into species differences regarding the biosynthesis of pregnane derivatives was afforded by Bush (1953), who demonstrated that various species differed in their adrenal secretion of cortisol and corticosterone. Interesting species differences have been observed by Idler and co-workers in fish. Thus, the Elasmo-branchii alone were found to possess la-hydroxycorticosterone in their blood stream and the responsible corticosterone la-hydroxylase in their interrenal tissue (Idler et al., 1969). la-Hydroxycorticosterone had approximately 80% of the sodium transport activity across the isolated toad bladder exhibited by d-aldosterone (Grimm et al., 1969). 

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