The role of endozepine in the regulation of adrenal steroidogenesis will be examined in bovine fasciculata and glomerulosa cells in relation to the production of cortisol and aldosterone respectively. In the fasciculata the transport of cholesterol from outer to inner mitochondrial membrane and the subsequent loading of the enzyme P-450scc in the inner membrane with cholesterol will be investigated since these steps are stimulated by endozepine. The first of these steps will be examined by coincubating and then separating the two membranes and the second will use Pure P-450scc to study the formation and properties of a complex that forms between the enzyme and endozepine. The complex will be studied by immunoprecipitation, cross-linking the ESR. Since endozepine does not bind cholesterol, the roles of other cholesterol-binding proteins in these phenomena will be examined using UV cross-linking with azidocholesterol. In glomerulosa cells the stimulation of the mitochondrial conversion of DOC to aldosterone will be examined with special reference to electron transport which plays a determining role in the synthesis of aldosterone. In particular an auxilliary source of electrons from NADH via a cytochrome b leading to reduction of ascorbate will be studied. This system will be reconstituted from the pure components isolated from the outer mitochondrial membrane. The action of endozepine on homogeneous P-45011b will be determined and possible effects of ACTH and angiotensin II on production of endozepine will be examined. The role of endozepine in fasciculata concerns the production of cortisol to enable the body to deal with all forms of stress - including the stress of disease, while the glomerulosa produces regulated amounts of the salt-retaining hormone aldosterone that is essential for normal life.
| Sleer, L S; Hall, P F (2000) Partial characterization of mitochondrial G proteins in adrenal cells. Biochim Biophys Acta 1463:99-106 |
| Thomson, M; Korn, M; Hall, P F (1995) GTP-binding proteins in adrenocortical mitochondria. Biochim Biophys Acta 1248:159-69 |
