The zona reticularis (sometimes, reticulate zone) is the innermost layer of the adrenal cortex, lying deep to the zona fasciculata and superficial to the adrenal medulla. The cells are arranged cords that project in different directions giving a net-like appearance (L. reticulum - net).[1]
In humans, the reticularis layer does contain 17α-hydroxylase; this hydroxylates pregnenolone, which is then converted to cortisol by a mixed function oxidase. Deficiency of 17α-hydroxylase results in low blood levels of estrogens, androgens, and cortisol, and the resultant compensatory increases in adrenocorticotrophic hormone stimulates the production of 11-deoxycorticosterone and corticosterone.[7] In rodents, the lack of 17α-hydroxylase results in the compensatory synthesis of corticosterone instead of cortisol.[8]