title: Relative contribution of P450c17 towards the acute cortisol response: Lessons from sheep and goats.
abstract: The rapid release of cortisol from the adrenal cortex upon ACTH receptor activation plays an integral role in the stress response. It has been suggested that the quantitative control over adrenal steroidogenesis (quantity of total steroids produced) depends on the activities of cytochrome P450 side-chain cleavage and steroidogenic acute regulatory protein that supplies pregnenolone precursor to the pathway. The qualitative control (which steroids) then depends on the downstream steroidogenic enzymes, including cytochrome P450 17α-hydroxylase/17,20-lyase (P450c17). In this review we focus on the relative contribution of P450c17 in the qualitative control of cortisol production with data collected from studies on South African Angora and Boer goats, as well as Merino sheep. Unique P450c17 genotypes were identified in these breeds with isoforms differing only with a couple of single amino acid residue substitutions. This review demonstrates how molecular and cellular differences relating to P450c17 activity can affect physiological and behavioural responses.
authors.affiliation: Department of Biochemistry, Private Bag X1, Stellenbosch University, Stellenbosch 7602, South Africa; Institute of Biodiversity, Animal Health and Comparative Medicine; College of Medical, Veterinary and Life Sciences; University of Glasgow; Glasgow G61 1QH, UK. Electronic address: denise.hough@glasgow.ac.uk.
authors.forename: D
authors.initials: D
authors.lastname: Hough
authors.affiliation: Department of Biochemistry, Private Bag X1, Stellenbosch University, Stellenbosch 7602, South Africa.
authors.forename: K
authors.initials: K
authors.lastname: Storbeck
authors.affiliation: Department of Animal Sciences, University of Stellenbosch, Stellenbosch 7602, South Africa; Western Cape Department of Agriculture, Private Bag X1, Directorate Animal Sciences: Elsenburg, Elsenburg 7607, South Africa.
authors.forename: S W P
authors.initials: SW
authors.lastname: Cloete
authors.affiliation: Department of Biochemistry, Private Bag X1, Stellenbosch University, Stellenbosch 7602, South Africa.
authors.forename: A C
authors.initials: AC
authors.lastname: Swart
authors.affiliation: Department of Biochemistry, Private Bag X1, Stellenbosch University, Stellenbosch 7602, South Africa.
authors.forename: P
authors.initials: P
authors.lastname: Swart
mesh_terms: D000311:Adrenal Glands / Q000378:metabolism; D000818:Animals; D006041:Goats / Q000378:metabolism*; D006854:Hydrocortisone / Q000378:metabolism*; D012756:Sheep / Q000378:metabolism*; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism*; D013256:Steroids / Q000096:biosynthesis
chemical_list: D013256:Steroids; D013254:Steroid 17-alpha-Hydroxylase; D006854:Hydrocortisone
keywords: CYP17; Cortisol; Cytochrome P450; HPA axis; Stress