The synthesis of adrenocortical steroid hormones involves a chain of oxidation-reduction reactions catalyzed by a series of enzymes.
The process is controlled by steroidogenic acute regulatory protein (StAR) which sits in the mitochondrial membrane and regulates the passage of cholesterol.
A coenzyme system called adrenodoxin reductase transfers electrons to the P450 enzyme which initiates the oxidation-reduction reactions that transform cholesterol into the steroid hormones.
It can be caused by either an adrenal tumor or by hypersecretion of adrenocorticotropic hormone (ACTH) from the anterior pituitary gland.
Sodium levels also see an increase which results in fluid retention in tissues and elevated blood pressure.
[8] In females, increased secretion of androgens, such as testosterone, results in masculinization which may present as facial hair growth and a deepened voice.
[2] Treatment for Cushing's syndrome aims to reduce the high levels of cortisol circulating through the human body.
Addison's disease is an autoimmune disorder that affects the adrenal cortex such that it is unable to efficiently secrete hormones.
The immune system specifically targets the cells of the adrenal cortex and destroys them, but Addison's disease can also be caused by a severe infection such as tuberculosis.
Because hydrocortisone is not able to be produced in Addison's disease, the pituitary gland continues to secrete corticotropin which binds to the receptor for melanocyte-stimulating hormone.
[9] The standard treatment for Addison's disease is hormone replacement therapy for the mineralocorticoids and glucocorticoids that are no longer able to be synthesized.