Characterisation of Female Rat Hepatic Testosterone 5alpha-Reductase

Beattie, James (1987) Characterisation of Female Rat Hepatic Testosterone 5alpha-Reductase. PhD thesis, University of Glasgow.

Abstract

Following a short discussion of steroid hormone biosynthesis and catabolism and mechanisms of action, the existing literature concerning the biochemistry of Delta4-3-oxosteroid 5a-oxidoreductase (E.C. 1.3.99.5; 5alpha-reductase) is reviewed under several main headings-viz. historical background, physiological and clinical significance of testosterone 5alpha-reduction, properties of hepatic and androgen-dependant tissue 5alpha-reductase, the mechanism of steroid 5alpha-reduction, the solubilisation of 5alpha-reductase and finally the hormonal control of 5alpha-reductase enzyme activity. Evidence is discussed concerning the possible relationship between enzymes of steroid hormone and fatty acid metabolism and at the end of the introduction the aims and scope of this investigation are delineated. The experimental section of this thesis is divided into five sections. In the first section, the microsomal 5alpha-reductase of female rat liver microsomes is characterised with respect to kinetic properties and pH optimum. In the next section experiments undertaken to solubilise the enzyme from microsomal membranes are described. The behaviour of solubilised enzyme on gel filtration is reported in the third section of results. The fourth part of the experimental work deals with the photo-affinity labelling of microsomal 5alpha-reductase. The specificity of photo-affinity labelling is described and the behaviour of the solubilised, photo-affinity labelled enzyme on gel filtration is reported and compared to the behaviour of solubilised 5alpha-reductase enzyme activity. Further characterisation of the radio-labelled conjugate by SDS-PAGE and stability of radio-ligand to precipitation and organic solvent extraction is also reported. In the final part of the results section experiments undertaken to elucidate the relationship between 5alpha-reductase and enoyl CoA reductase (a microsomal enzyme involved in fatty acid metabolism) are described. The results obtained are discussed in relation to the findings obtained by other workers at the end of each appropriate experimental section. In the final chapter, some conclusions are derived from the experimental work and some suggestions for future investigations are forwarded.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Endocrinology
• Date of Award: 1987
• Depositing User: Enlighten Team
• Unique ID: glathesis:1987-77623
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jan 2020 11:53
• Last Modified: 14 Jan 2020 11:53
• URI: https://theses.gla.ac.uk/id/eprint/77623