Adrenocortical hormones biosynthesis

Outline of major pathways in adrenocortical hormone biosynthesis. The major secretory products are underlined. Pregnenolone is the major precursor of corticosterone and aldosterone, and 17-hydroxypregnenolone is the major precursor of cortisol. The enzymes and cofactors for the reactions progressing down each column are shown on the left and across columns at the top of the figure. When a particular enzyme is deficient, hormone production is blocked at the points indicated by the shaded bars. 

Drugs That Inhibit Adrenocortical Hormone Biosynthesis... 

Outline of major pathways in adrenocortical hormone biosynthesis. The major secretory products are underlined. Pregnenolone is the major precursor of corticosterone and aldosterone, and 17-... 

Haynes, R.C., and Murad, F. (1985). Adrenocorticotropic hormone adrenocortical steroids and their synthetic analogs inhibitors of adrenocortical steroid biosynthesis. In Goodman and Gilman s The Pharmacological Basis of Therapeutics (Goodman, A.G., Goodman, L.S., Rell, T.W. and Murad, F., Eds.). Macmillan, New York, pp. 1459-1489. 

We first describe the biosynthesis of fatty acids, the primary components of both triacylglycerols and phospholipids, then examine the assembly of fatty acids into triacylglycerols and the simpler membrane phospholipids. Finally, we consider the synthesis of cholesterol, a component of some membranes and the precursor of steroids such as the bile acids, sex hormones, and adrenocortical hormones. 

Ascorbic acid may be required for steroid hormone biosynthesis depleted from adrenal cortex on cortical secretion Biotin adrenocortical insufficiency noted in biotin deficiency... 

Four pharmacologic agents are useful inhibitors of adrenocortical secretion. Mitotane (o,p -DDD), an adrenocorticolytic agent, is discussed in Chapter 51. The other inhibitors of steroid hormone biosynthesis are aminoglutethimide, ketoconazole, and trilostane. Aminoglutethimide and ketoconazole are... 

Cholesterol, the most abundant steroid, is an important constituent of cell membranes and the starting material for biosynthesis of other steroids. This includes the sex hormones, such as progesterone, estradiol, testosterone, and androsterone, adrenocortical hormones such as aldosterone and cortisone, bile salts, and vitamin D. 

Anatomical Considerations 458 Histophysiology 459 Adrenocortical Hormones 460 Steroid Hormone Biosynthesis Metabolic Effects of Corticoid Hormones Properties of ACTH Cushing s Syndrome... 

These results establish that 21-hydroxy pregnenolone can act as an intennediary in the biosynthesis of adrenocortical hormones during fetal life, but the quantitative contribution of this route is not yet established. It can be concluded that the d/S-hydroxydehydrogenase, A A. isomerase activity for 21-hydroxyj)regnenolone in the placental tissue is as active as for pregnenolone. 

The enzymatic oxidation of alkanes to produce alcohols is a simplified version of the reactions that produce the adrenocortical steroid hormones. In the biosynthesis of corticosterone from progesterone (Section 4-7), two such oxidations take place successively (a, b). It is thought that the monooxygenase enzymes act as complex oxygen-atom donors in these reactions. A suggested mechanism, as applied to cyclohexane, consists of the two steps shown below the biosynthesis. 

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