Pathophysiology Review
The adrenal glands rest on the superior and medial side of each kidney at the 11th and 12th thoracic vertebrae. Like other endocrine glands, they are very well vascularized. Each adrenal gland comprises two different glands encapsulated as one: the adrenal cortex on the outer surface and the medulla on the inside.
Adrenal Cortex
The adrenal cortex has three regions — the zona glomerulosa, the zona fasciculata, and the zona reticularis — that produce mineralocorticoids, glucocorticoids, and androgens. The outer zona glomerulosa secretes hormones, such as aldosterone and other mineralocorticoids, which control fluid/electrolyte balance. The zona fasciculata secretes cortisol and other glucocorticoids, as does the zona reticularis.
The pituitary gland’s secretion of ACTH stimulates glucocorticoid production, the main glucocorticoid being cortisol. The pituitary gland is in turn regulated by corticotrophin-releasing factor (CRF), which is secreted from the hypothalamus. Like most hormone systems in the body, these hormones are controlled by a negative feedback loop.
Cortisol has a number of physiological functions, including promoting and enhancing gluconeogenesis enzymes in the liver to keep blood glucose levels high. This is the reason that diabetic patients under high stress will need to increase drug dosages to compensate for the increased blood sugar levels.Cortisol also increases hepatic protein synthesis and protein catabolism at the same time, and stimulates hormone sensitive lipase and the release of fatty acids from adipose tissue.
Adrenal Medulla
The adrenal medulla consists of secretory cells, 80% of which produce and release epinephrine, while the remaining 20% secrete norepinephrine. These secretory cells are actually modified postganglionic neurons. This embryological fact is crucial for the ‘fight or flight’ reaction in response to life threatening situations.
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Adrenal Hormones
Adrenal Medulla
Hormone Group Catecholamines, adrenaline (epinephrine), noradrenaline (norepinephrine)
Function Neurotransmitters, fight or flight, increase blood pressure, catabolic, insulin resistance
Pathology Pheochromocytoma, hyperfunctioning
Symptoms Headaches, diaphoresis, palpitations
Therapeutic Surgery, Rauwolfia serpentina (reserpine)
Adrenal Cortex
Hormone Group Glucocorticoids, cortisone, hydrocortisone (cortisol)
Function Anti-inflammatory, gluconeogenesis
Pathology Adrenal insufficiency
Symptoms Weakness, fatigue, anorexia, nausea
Therapeutic Hydrocortisone, Cortisone acetate, Glycerhhizic acid, Sarsparilla, Ginseng, Licorice Solid Extracts
Hormone Group Androgens, testosterone, androstenedione, dehydroepiandrosterone
Function Androgenic, anabolic, increase uric acid
Disorder Adrenal insufficiency
Symptoms Weakness, fatigue
Therapeutic DHEA, pregnenolone, androstenedione, testosterone, lifestyle
Hormone Group Mineralocorticoids, 11-deoxycorticosterone (DOC), aldosterone
Function Increase blood pressure, increase Na/k ratio
Disorder Primary aldosteronism (excessive aldosterone), functional hypofunction
Symptoms Hypertension
Therapeutic Surgery, dexamethasone, functional hypofunction: salt, licorice, Sarsparilla solid extract
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Selected Clinical Studies and Literature Reviews
For a discussion of the biochemistry of adrenal metabolism, see Abram Hoffer, “Dopamine, Noradrenaline, and Adrenalin Metabolism to Methylated or Chrome Indole Derivatives: Two Pathways or One? “ in Selected Clinical Studies and Literature Reviews. _________________
