Progesterone -> (hydroxylation at C17)-> 17-alpha-hydroxyprogesterone ->(hydroxylation)-> Deoxycortisol ->(hydroxylation)-> Cortisol.Progesterone -> (hydroxylation at C21)-> Deoxycorticosterone ->(two further hydroxylations)-> Aldosterone.Subsequent steps, however, only occur in the adrenal cortex: The steps up to this point occur in many steroid-producing tissues. Pregnenolone can be either dehydrogenated to progesterone, or hydroxylated to 17-alpha-hydroxypregnenolone.Cholesterol is converted into pregnenolone by the enzyme CYP11A1 after transportation into the inner mitochondrial membrane by the steroidogenic acute regulatory protein ( STAR). Accordingly, production of hormones in all three layers of the adrenal cortex is limited by the transportation of cholesterol into the mitochondria and by its conversion into pregnenolone.All adrenocortical hormones are synthesised from cholesterol.Weak androgens (eg, dehydroepiandrosterone)
The cortex can be divided into three distinct layers of tissue based on their organization.
