Adrenal Gland Hormones

Sample for Adrenal Gland Hormones

1. The serum of the patient is required.
2. The urine sample may be used.
3. For catecholamines (Epinephrine and Norepinephrine), plasma in heparin or EDTA is needed.
   • Transport this plasma on the ice and centrifuged at 4 C within 30 minutes and separate the plasma. Now freeze till the test is run.
   • Urine may be collected for 24 hours. Add 6 M HCl and Refrigerate during collection.
4. For Cortisol, Serum is needed. Can use heparinized plasma.
   • Urine for 24 hours is collected with the addition of boric acid.
   • The serum is stable for 2 days at 2 to 8 °C.
5. Aldosterone test can be done on plasma (heparin, EDTA, or citrate). 
   • The serum can also be used.
   • The patient must be upright for 2 hours before the sample is taken.
   • Urine 24 hours is collected with boric acid, and during collection, it is refrigerated.
6. Estrogen can be estimated in the serum.
   • The serum needs to be frozen immediately after collection.
   • A urine 24 hours sample is collected with the addition of boric acid.

Precautions before performing the Adrenal gland tests:

1. A fasting sample is needed.
2. Avoid exercise or physical activity.
3. Reduce stress before performing this test.
4. Avoid herbal medicines and any medication which interferes with the test.
5. Avoid a nuclear scan before this test.
6. THE aldosterone AM sample is higher than PM.
7. Cortisol’s highest level is 8 AM  and >50% less at 8 PM.
   1. Transport the plasma on ice to the lab.
   2. Centrifuge at 4 °C.

Pathophysiology of Adrenal Gland Hormones

1. Adrenal glands consist of:
   1. The adrenal medulla is grey in color.
   2. The adrenal cortex is yellow in color.
      1. The adrenal cortex is derived from the mesoderm.
      2. These hormones maintain the homeostasis of the body.
      3. The adrenal medulla is derived from the ectoderm.
   3. Adrenal gland measure:
      1. Wide = 2 to 3 cm.
      2. Length = 4 to 6 cm.
      3. Thickness = 1 cm.
      4. Weight approximately = 4 grams (regardless of the age and the sex).

The adrenal cortex hormones.

1. Steroid hormones are synthesized from the cholesterol in the adrenal glands and gonads.

1. 1. The nature and quantity of the steroid hormone produced by the adrenal glands and gonads differ.
   2. The ovaries and testes contain enzymes that synthesize the male and female sex hormones.
   3. Steroid hormones circulate in the blood in free and bound forms.
   4. In plasma, these are bound to the carrier protein or albumin.
   5. Steroid hormones conjugate to glucuronide or sulfate, and are excreted by the kidneys or gastrointestinal tract.
   6. Steroids 90% to 96% have a high affinity for the carrier protein, globulin.
   7. In the case of low affinity for carrier protein, 60% to 70% of the circulating steroids are bound to albumin.
   8. Androgens produced by the theca cells of the ovary are converted to estrogen.

2. Mineralocorticoid like aldosterone regulates sodium and potassium.
   1. Aldosterone is the major Mineralocorticoid produced by the adrenal cortex, 200 µg/day.
   2. It promotes renal K⁺ excretion and increases water retention by increasing renal Na⁺ retention.
   3. It increases the plasma concentration of the Na⁺ by increasing the Na⁺ absorption in the renal tubules.
   4. Aldosterone is present in a very minute amount in the plasma, so difficult to measure with accuracy.
   5. If someone is standing for a long time then his plasma aldosterone level will be between 5 to 20 ng/dL.
   6. If the person is in the lying position for several hours, then the aldosterone level will fall and maybe 10% to 40% less than the upright position.
   7. Metabolism of Aldosterone:
      1. The liver converts aldosterone into glucuronide and tetrahydro-glucuronide, this will be excreted in the urine.
      2. Kidneys also inactivate aldosterone by changing it into water-soluble glucuronide.
   8. Hyperaldosteronism is usually due to an adrenal tumor that has S/S of:
      1. Increased serum Na⁺.
      2. Decreased K⁺.
      3. Hypertension.
      4. Plasma aldosterone level is increased.
      5. Urine excretion of aldosterone is also increased.

Primary aldosteronism is due to:

1. Adrenal tumor, usually adenoma of the adrenal cortex.
2. Bilateral nodular hyperplasia.

Secondary aldosteronism is stimulated by:

1. Low serum Na⁺ level.
2. ACTH
3. High serum K⁺ level.

Primary aldosteronism can be differentiated from the secondary causes of aldosteronism.

Lab test	Primary aldosteronism		Secondary aldosteronism
	Hyperplasia	Adenoma	Edema (CCF and Cirrhosis)	Accelerated Hypertension
Aldosterone level	Increased (+)	Increased (+)	Increased (++)	Increased (+)
Plasma renin level	Normal/Increased	Decreased (++)	Increased (+)	Increased (++)
Serum Na+	Normal	Normal/Increased	Normal/Decreased	Normal/Decreased
Serum K+	Normal/Decreased	Decreased (+)	Normal/Decreased	Normal/Decreased
Hypertension	Increased (+)	Increased (++)	Normal/Increased	Increased (++++)
Edema	Negative	Negative	Present	Negative

Glucocorticoids:

1. It is like cortisol which is gluconeogenic. Cortisol is the most potent glucocorticoid.
   1. Cortisol is produced at 25 mg/day by the adrenal cortex.
   2. It regulates intermediary carbohydrate metabolism.
   3. Functions of glucocorticoids:
      1. It has a metabolic function.
      2. It has an inflammatory function.
      3. This is also anti-inflammatory.
      4. It has a growth suppressing effect.
      5. It influences the level of awareness and sleep pattern.
   4. Glucocorticoids have a direct effect on glucose levels and it increases the glucose level.
   5. Glucocorticoids’ main function is in Carbohydrate metabolism. There is gluconeogenesis in the liver and there is a decrease in glucose levels in the muscle, adipose tissue, and lymphatic tissue.
   6. In extrahepatic tissue, Glucocorticoids antagonize insulin.

Cortisol

1. Cortisol is the most potent naturally occurring glucocorticoid.
2. The daily secretion of cortisol is 25 mg/day. But the plasma shows a level of 6 to 25 µg/dL.
3. Cortisol is formed from the cholesterol in the zona fasciculata and zona reticularis of the adrenal cortex.
4. When cortisol is released into the circulation, it binds with corticosteroid-binding globulin and is transported as such.
5. Cortisol is metabolized and conjugated in the liver to several inactive forms.
   1. >90% of cortisol and its metabolite cortisone is conjugated with glucuronic acid and excreted in the urine as a conjugate.
   2. <2% of cortisol which is not metabolized, is excreted in the urine as free cortisol.
   3. Cortisol and its oxidation product cortisone, are inactivated in the liver by two separate processes:
      1. The reduction process is hydrogenation to tetrahydro-derivatives.
      2. These products are conjugated with glucuronic acid and excreted in the urine.
   4. 30% to 50% of these appear in the form of glucuronide conjugates of tetrahydro-derivates of cortisol and cortisone.
      1. All these compounds contain a dihydroxyacetone group in the side chain and these are known as 17-hydroxycorticosteroid (17-OHCS).
      2. 17-hydroxycorticosteroid (17-OHCS) can be estimated chemically by the RIA kits. In the past Porter-Silber reaction was used but now it is obsolete.
   5. The determination of the plasma cortisol is useful to diagnose adrenocortical diseases, both hypo- and hyper conditions.
6. Not >1% of the total cortisol synthesized in the body daily is excreted as such in the urine.
7. Functions of the cortisol:
   1. Cortisol acts on the target cells by penetration and transport to the cell nucleus.
   2. It will bind the DNA and alter the transcription of RNA.
   3. Cortisol alters the various metabolic process.
   4. It accelerates the enzymatic breakdown of the muscle proteins and the conversion of their amino acids into glucose.
   5. Fat is metabolized for provision of the energy.
   6. Cortisol acts antagonistic to the insulin action, by inhibiting the uptake of glucose by the muscles.
   7. It decreases the cellular reaction to the inflammatory agents.
   8. It decreases antibody formation, leading to poor immune response.
   9. This is the main hormone of the adrenal cortex to maintain life and protect the body from stress.
8. Hypothalamus hormone CRH travels through the portal circulation to stimulate the production of ACTH, β-lipoprotein, γ-lipoprotein, endorphins, and enkephalins by the anterior pituitary.
9. Cortisol secretions follow ACTH stimulation of the adrenal cortex, and ACTH is the main regulator of cortisol secretion and adrenocortical growth.
10. Cortisol is transported in plasma as:
    1. 85% is transported by corticosteroid-binding globulin (CBG called transcortin).
    2. 10% bound to albumin.
    3. 5% is in free form (not bound to proteins).
11. The cortisol follows the ACTH pattern, it is high early in the morning and lowest at midnight.

12. Cortisol inhibits the secretion of ACTH from the pituitary gland and also inhibits CRH from the hypothalamus.

Adrenal androgens:

1. It is like such as dehydroepiandrosterone (DHEA) and androstenedione. These are also called sex hormones.
2. The adrenal androgens include:
   1. DHEA is the principal androgen, secreted at 20 mg/day.
   2. Testosterone (converted to estradiol).
   3. DHEA is converted to Androstenedione which in turn is converted to estrone.

The adrenal medulla

• It is a neuroendocrine gland that secretes:

1. Epinephrine.
2.  Norepinephrine.
   1. Both act on the sympathetic nervous system.
      1. These hormones regulate the acute response of the body to external stimuli.

ACTH hormone:

1. ACTH (Adrenocorticotropin hormone) from the pituitary gland stimulates the adrenal cortex.
   1. After stimulation of the adrenal cortex by the ACTH, the process of steroidogenesis starts from the cholesterol.
2. The pituitary gland (ACTH) is stimulated by the Hypothalamic hormone (Corticotropin-releasing factor (CRH).

3. Serum ACTH level has a diurnal variation:
   1.  The peak level is at 7 AM at about 200 pg/ml.
   2. ACTH level declines and the lowest level is at midnight around 100 pg/ml.
   3. ACTH secretion depends upon:
      1. High circulating levels of cortisol suppress ACTH and CRH. While the low level of cortisol stimulates their secretion.
      2. There is diurnal variation in the secretion of ACTH and cortisol levels. There is a sleep-wake pattern. ACTH peak is 3 to 5 hours after sleep begins and declines throughout the day. Cortisol follows the same pattern.
      3. Stress increases the ACTH secretion, which will lead to increased cortisol levels.
   4. The peak level is from 8.00 to 9.00 AM. The highest level is in the early morning and the lowest at midnight.

Normal level of adrenal gland hormone

• Epinephrine  = <50 pg/mL
  • Urine epinephrine = 0 to 20 µg/ day
• Norepinephrine  =  110 to 410 pg/mL
  • Urine norepinephrine = 15 to 80  µg/ day
• Dopamine = <87 pg/mL
  • Urine dopamine = 65 to 400 µg/ day
• Cortisol Total
  • Cord blood = 5 to 17 µg/dL
  • Infants = 2 to 11 µg/dL
  • Child 1 to 16 years at 8 am = 3 to 21 µg/dL
  • adult   8 am = 5 to 23 µg/dL
    • 4 pm = 3 to 16 µg/dL
  • Urine cortisol (free)  =
    • Adult = 20 to 90 µg/ day  or (<100 µg/day)
    • Child = 2 to 27 µg/day
• Aldosterone
  • Cord blood =  40 to 200 ng/dL
  • Full term infant 3 days = 7 to 184 ng/dL
  • Infants 1 to 12 months = 5 to 90 ng/dL
  • Children 1 to 2 years = 7 to 54 ng/dL
  •  Children 2 to 10 years =
    • Supine postion = 3 to 35 ng/dL
    • Upright position = 4 to 48 ng/dL
  • Adult
    • Supine postion = 3 to 16 ng/dL
    • Upright position = 7 to 30 ng/dL
• Estrogen Total
  • Male   =  20 to 80 pg/mL.
  • Female
    • Luteal phase = 160 to 400 pg/mL.
    • Follicular phase = 60 to 200 pg/mL.
    • Postmenopausal = <130 pg/mL

Lab tests for various adrenal gland dysfunctions:

Adrenal Hyperfunction leads to:

1. Excess of Cortisol causes  Cushing’s syndrome.
2. Excess of Aldosterone causes Hyperaldosteronism.
3. Excess of Androgens causes Virilizing syndrome.

Primary Hyperadrenalism:

1. The cortisol level is raised.
2. ACTH level decreases.

Primary Adrenal Insufficiency (Addison’s disease):

This is due to the diseases of the gland.

1. The cortisol level is decreased.
2. Serum sodium is low.
3. The glucose level is decreased.
4. ACTH level is raised.
5. Potassium, calcium, and blood urea are raised.

Secondary Hypoadrenalism (secondary or tertiary Adrenal insufficiency):

This is due to external factors that lead to the under-activity of the glands.

1. Cortisol level is decreased
2. ACTH level is low.

Cushing’s syndrome:

1. There is no diurnal variation of ACTH, and it is absent.
2. There is an elevated level of Cortisol, Glucose, and Sodium.
3. There is a decreased Potassium level.

Adult adrenogenital syndrome:

1. There is an elevated level of:
   1. DHEA
   2. Urine 17- ketosteroids
   3. ACTH
2. There is a decreased level of:
   1. Cortisol

Congenital Adrenal Hyperplasia:

1. There is an elevated level of:
   1. ACTH
   2. Androgens level
2. Decreased level of:
   1. Cortisol
   2. Aldosterone

Primary Hyperaldosteronism (Conn’s syndrome):

1. There is an elevated level of:
   1. Aldosterone urine and blood
   2. Serum sodium
2. There is a decreased level of:
   1. Potassium.
   2. Renin.
   3. No response to the aldosterone suppression test.

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