exactly 14 - Hormones of adrenal cortex – glucocorticoids. Physiological effects and control of secretion. Pharmacologic effects of glucocorticoids (GCC) . Hormones of adrenal cortex – mineralcorticoids and adrenal androgens. Abnormalities of adrenocortical secretion.

sections

hormones of adrenal cortex

what do they hromones do

regulation of synthesis of hromones

pharmacological effects

hormones of adrenal cortex

• Cortex (secretes Glucocorticoids, Mineralocorticoids and androgens) Glucocorticoids are steroids of the suprarenal cortex

  1. Cortisol

  2. Cortisone

  3. Corticosterone

  They are a major stress hormone

what do they hromones do

1. Increase rate of protein catabolisim and amino acids are transported to the liver to be synthesized into new proteins.

2. Stimulate the(lipolysis) breakdown of fat and the release of fatty acids from adipose tissue as an additional energy source.

3. Help provide resistance to stress.

4. Glucocorticoids are anti-inflammatory compounds, -inhibit release of chemicals that cause inflammation

5. Stimulate gluconeogenesis- production of glucose for energy

6. Stimulates erythropoietin hormone—RBC production

regulation of hormone sythesis

• The synthesis of glucocorticosteroids is positively stimulated by CRH from the hypothalamus and ACTH from adenohypophysis.

• CRH secretion is stimulated by noradrenergic regions/ neurons in the CNS. When the CRH reaches the adenohyophysis – the synthesis and secretion of ACTH is stimulated

• ACTH binds to receptors on the adrenocortical cells of the adrenal cortex where it enhances the expression of cortisol

• Cortisol inhibits its own synthesis and secretion by negative feedback regulation of hypothalamus

• Cortisol also has a circadian rhythm which is usually found to be high in the morning but low in evenings

pharmacological effects

• Maturation of organs

• Prenatal effects on maturation of lungs

• Development of suprarenal medulla, immune system (thrombocytes differentiation) and Erythropoiesis

• Stress hormone

Can be given orally if person has:

• Needs Physiological replacement of glucocorticoids

• Therapeutic immunosuppression by lowering activity of lymphocytes

• Treatment of asthma

• Anti-inflammatory effects by synthesis of lipocortin-1 that blocks various leucocyte depending inflammatory events. It inhibits immune response and prostaglandins and leukotriens

sections

mineralcorticoids

aldosterone

adrenal androgens

abnormalities of adrenocortical secretion

overproduction of androgen

overproduction of aldo sterone

addisons disease

cushings disease

mineralcorticoids

• Mineralocorticoids – secreted from zona glomerulosa are a class of corticosteroid hormones of the adrenal cortex

• Involved in homeostasis of water, sodium ions (Na), and potassium ions (K+).

• Lipophilic hormones

• The mineralocorticoid- Aldosterone acts on certain cells in the kidneys to increase their reabsorption of sodium ions from the urine.

• Are involved in the regulation of electrolyte and fluid balance

• principal mineralocorticoid is aldosterone.

• Aldosterone acts on kidneys to provide active reabsorption of na+ ions and passive reabsorption of water, as well as active secretion of K+ ions.

• Water follows sodium

• This occurs in response to fluid and electrolyte deficiency in the blood

• causes an increase in blood pressure and blood volume

• aldosterone is Stimulated by angiotensin II, increased plasma Potassium, or fall in plasma Sodium. Inhibited by ANP and BN

aldosterone

Aldosterone activates mineralocorticoid receptors which usually have a high affinity for cortisol. Consequently by intracellular mechanisms- cortisol is converted to cortisone so that aldosterone can now bind to the receptor, therefore stimulating expression of SGK hormone enzyme. An enzyme that blocks the removal of the Na+/K+ pump. This facilitaes Na+ influx and k+ efflux.

adrenal androgens

• secreted by cells of the adrenal cortex-zona reticularis

• DHEA- dihydroepiandosterone

• Androstenedione—promotes metabolism and protein anabolism ad growth

• Male sex hormones. They stimulate / controlling the maintenance and development of male characteristics

• Testosterone is an androgen– needed for sperm production- testosterone made in testes not the adrenal cortex

• Although androgens are described as male sex hormones, both males and females have them at varying levels.

• levels increase during early 20- puberty, gradually fall during old age

• Involved in testes formation, male aggression, development of muscle tone and mass.

• In females, androgens contribute to sex drive (libido).

abnormalities of adrenocortical secretion

The adrenal glands can become either overactive or underactive.

• Cushing's syndrome and Addison's disease

1. Cushing’s syndrome -overactive adrenal glands from excessive production of cortisol.

   • Muscle weakness

   • Obesity

   • high blood pressure,

   • moon face

2. Addisons disease-low level of cortisol production from adrenal cortex

   • low blood pressure

   • fatigue

   • weight loss

   • hypoglycemia

overproduction of androgen

is rare but may result in excessive hair growth and menstrual period disturbances.

overproduction of aldosterone

leads to hyperaldosteronism and cause high blood pressure

addisons disease

cushings disease