Adrenal Glands

Anatomy of the adrenal glands:

Adrenal glands, which are also called suprarenal glands, are small, triangular glands located on top of both kidneys. An adrenal gland is made of two parts: the outer region is called the adrenal cortex and the inner region is called the adrenal medulla.

Function of the adrenal glands:

The adrenal glands work interactively with the hypothalamus and pituitary gland in the following process:

• the hypothalamus produces corticotropin-releasing hormones, which stimulate the pituitary gland.
• the pituitary gland, in turn, produces corticotropin hormones, which stimulate the adrenal glands to produce corticosteroid hormones.

Both parts of the adrenal glands -- the adrenal cortex and the adrenal medulla -- perform very separate functions.

What is the adrenal cortex?

The adrenal cortex, the outer portion of the adrenal gland, secretes hormones that have an effect on the body's metabolism, on chemicals in the blood, and on certain body characteristics. The adrenal cortex secretes corticosteroids and other hormones directly into the bloodstream. The hormones produced by the adrenal cortex include:

• corticosteroid hormones
  • hydrocortisone hormone - this hormone, also known as cortisol, controls the body's use of fats, proteins, and carbohydrates.
  • corticosterone - this hormone, together with hydrocortisone hormones, suppresses inflammatory reactions in the body and also affects the immune system.
• aldosterone hormone - this hormone inhibits the level of sodium excreted into the urine, maintaining blood volume and blood pressure.
• androgenic steroids (androgen hormones) - these hormones have minimal effect on the development of male characteristics.

What is the adrenal medulla?

The adrenal medulla, the inner part of the adrenal gland, is not essential to life, but helps a person in coping with physical and emotional stress. The adrenal medulla secretes the following hormones:

• epinephrine (also called adrenaline) - this hormone increases the heart rate and force of heart contractions, facilitates blood flow to the muscles and brain, causes relaxation of smooth muscles, helps with conversion of glycogen to glucose in the liver, and other activities.
• norepinephrine (also called noradrenaline) - this hormone has little effect on smooth muscle, metabolic processes, and cardiac output, but has strong vasoconstrictive effects, thus increasing blood pressure.

From: University of Maryland Center for Diabetes and Endocrinology

A Pill That Stops Stress In Your Brain Before You Feel It

Stress makes many of us miserable — but it can also kill you. Besides just causing horrible anxiety and depression, the physiological basis for stress has also been linked to diseases as varied as obesity, postpartum depression, Cushing's syndrome, epilepsy, and osteoporosis. But what if we could just turn your brain's stress response off?

Now, researchers from Tufts claim to have pinpointed the way that stress hormones hit specific receptors in your brain — and they've even been able to block them. This could lead to the next great psychopharmaceutical breakthrough.

The Tufts researchers discovered that stress pathways are activated by neurosteroids acting on corticotrophin-releasing hormone neurons in what's known as the Hypothalamus-Pituitary-Adrenal axis. By blocking the synthesis of the neurosteroids, they stopped the elevation of corticosterone, and prevented anxiety in mice.

"We have identified a novel mechanism regulating the body's response to stress by determining that neurosteroids are required to mount the physiological response to stress. Moreover, we were able to completely block the physiological response to stress as well as prevent stress-induced anxiety," said author Jamie Maguire, PhD.

Now the team is focusing on modulating the neuroreceptors to treat some of the diseases that accompany stress — be they depression, anxiety, or epilepsy.

From http://io9.com/5867762/a-pill-that-stops-stress-in-your-brain-before-you-feel-it

Glucocorticoid- and Androgen-Secreting Black Adrenocortical Adenomas: Unique Cause of Corticotropin-Independent Cushing Sydrome

	Glucocorticoid- and Androgen-Secreting Black Adrenocortical Adenomas: Unique Cause of Corticotropin-Independent Cushing Sydrome Journal Endocrine Practice Publisher American Association of Clinical Endocrinologists ISSN 1530-891X (Print) 1934-2403 (Online) Subject Health Services, Medical Sciences and Endocrinology Issue Volume 17, Number 3 / May-June 2011 Pages e73-e78 Online Date Thursday, June 23, 2011

PDF (1.8 MB)

Authors

Satoshi Tanaka, MD, PhD¹, Akiyo Tanabe, MD, PhD¹, Motohiko Aiba, MD, PhD², Naomi Hizuka, MD, PhD¹, Kazue Takano, MD, PhD¹, Jun Zhang, MD³, William F. Young, MD, MSc, Jr.⁴

¹Department of Medicine, Tokyo Women's Medical University, Tokyto, Japan
²Department of Clinical Pathology, Tokyo Women's Medical University Medical Center East, Tokyo, Japan
³Department of Anatomic and Clinical Pathology, Mayo Clinic, Rochester, Minnesota
⁴Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Rochester, Minnesota

Abstract

Objective: To describe the unique association of corticotropin-independent Cushing syndrome caused by cortisol- and androgen-secreting black adrenal cortical adenomas with myelolipomatous change.

Methods: We report the clinical, laboratory, radiologic, and pathologic findings from 2 patients who presented with androgen excess and typical signs and symptoms of Cushing syndrome.

Results: Endocrine investigations showed high serum cortisol concentrations that lacked diurnal rhythm, undetectable plasma corticotropin concentrations, and absence of serum cortisol suppression after overnight dexamethasone suppression tests. Serum levels of adrenal androgens were elevated. Computed tomography of the abdomen revealed unilateral adrenal masses (largest lesional diameters 4.0 and 3.1 cm). On the basis of the plurihormonal hypersecretion and the imaging characteristics, adrenocortical carcinoma was considered as a possible diagnosis. However, histopathologic analysis in both patients revealed black adrenal cortical adenomas with myelolipomatous change. After surgery, adrenal androgens normalized, and the signs and symptoms of Cushing syndrome and androgen excess resolved. There was no evidence of recurrent disease at last follow-up.

Conclusions: A unique form of corticotropin-independent Cushing syndrome is described: cortisol- and androgen-secreting black adrenal cortical adenomas with myelolipomatous change. Although most patients with corticotropin-independent Cushing syndrome associated with androgen excess prove to have adrenocortical carcinoma, the clinician should be aware of the possibility of benign, black adrenal adenomas in this clinical setting.

Show References

From http://aace.metapress.com/content/yg61xw4671161wg6/