Metabolism of steroid hormones

Steroid hormones are synthesized primarily in the adrenal gland and gonads. They regulate energy metabolism and stress responses (glucocorticoids), salt balance (mineralocorticoids), and sexual development and function (androgens and estrogens). All steroids are synthesized from cholesterol. Steroid hormone synthesis is largely regulated at the initial steps of cholesterol mobilization and transport into the mitochondrial matrix for conversion to pregnenolone. In the body, the fate of pregnenolone is tissue-specific: in the zona fasciculata of the adrenal cortex it is converted to cortisol, in the zona glomerulosa to aldosterone, and in the gonads to testosterone and then to estrone and estradiol. These pathways are outlined in the figure below, which also details the sites on the cholesterol molecule that undergo modification in the course of these reactions.

类固醇激素主要由肾上腺和生殖腺合成。它们调控能量代谢和应激反应（糖皮质激素）、盐平衡（盐皮质激素）以及性发育与功能（雄激素和雌激素）。所有类固醇均源自胆固醇。类固醇激素的合成主要受胆固醇动员及其转运至线粒体基质以转化为孕烯醇酮的初始步骤所调节。在体内，孕烯醇酮的组织特异性命运如下：在肾上腺皮质的束状带，其转化为可的松；在球状带，转化为醛固酮；在生殖腺，转化为睾酮，进而转化为雌酮和雌二醇。以下图示详细阐述了这些途径，并说明了胆固醇分子在反应过程中发生修饰的位点。