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.
Epidural Steroid Injection Procedures are a common and minimally invasive procedure to treat inflammation present inside the spinal canal. This inflammation can occur in the spinal nerve, due to tissues next to the nerve (disc, facet joints, scar tissue, bone spurs, bone material) pressing or rubbing against it. The beginning of the nerve (nerve root) is most often irritated by an displaced intervertebral disc, bulged, herniated (protrusion, extrusion, sequestration) or a diseased disc (torn, fissured, collapsed, degenerated), directly.
The disease is initially treated with steroid (prednisone) and following complete remission of the clinical signs the dose can be reduced. How fast the dose is reduced often is related to how well the patient is tolerating what can be the unpleasant and even dangerous side-effects of steroids. For more information on these side-effects, please see our informational sheet on “Steroids.” If the patient relapses while we are lowering the dosage of steroid, we will often restart steroid therapy along with an immune suppressive medication like Cyclosporine. For more information on Cyclosporine, please see our medication handout series.