One study has been conducted in athletes given D-aspartic acid supplementation at a dose of 3g daily for 28 days, and there was a failure to increase testosterone concentrations when measured at 28 days.  This study noted a statistically significant induction of serum D-aspartate oxidase (DAO) which degrades D-aspartate  to a near doubling;  this suggests a possible form of negative feedback, and aromatase (may also be induced by D-aspartic acid  ) was not thought to contribute due to estrogen being unchanged.
Cells of the zona fasciculata and zona reticularis lack aldosterone synthase (CYP11B2) that converts corticosterone to aldosterone, and thus these tissues produce only the weak mineralocorticoid corticosterone. However, both these zones do contain the CYP17A1 missing in zona glomerulosa and thus produce the major glucocorticoid, cortisol. Zona fasciculata and zona reticularis cells also contain CYP17A1, whose 17,20-lyase activity is responsible for producing the androgens, dehydroepiandosterone (DHEA) and androstenedione. Thus, fasciculata and reticularis cells can make corticosteroids and the adrenal androgens, but not aldosterone.
The regulatory domains of cPKC isoforms (cPKCα: cPKC-alpha; cPKCβI: cPKC-beta I, cPKCβII: cPKC-beta II; and cPKCγ: cPKC-gamma) contain a C1 domain consisting of tandem ~50 amino acid long sequences termed C1A and C1B. The C1A and C1B subdomains each have six cysteines and two histidines that coordinate two Zn 2+ ions. The cPKCβII enzyme is an alternatively spliced version of cPKCβI. The C1A/C1B motifs function as a DAG-/PMA-binding motif (PMA: phorbol myristic acid). The regulatory domains of the cPKC isoforms also contain a C2 domain that binds anionic phospholipids in a calcium-dependent manner. All the cPKC isoforms require DAG, Ca 2+ , and phospholipids for activation.