Hypersecretion of Adrenal Cortex Hormone .
Hypersecretion of adrenocortical hormones leads to the following conditions:
1. Cushing syndrome .
2. Hyperaldosteronism .
3. Adrenogenital syndrome.
Cushing syndrome .
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| Cushing syndrome . |
Cushing syndrome is a disorder characterized by obesity.
Causes of Cushing syndrome .
[1]. Cushing syndrome is due to the hypersecretion of glucocorticoids, particularly cortisol.
[2]. It may be either due to pituitary origin or adrenal origin.
[3]. If it is due to pituitary origin, it is known as Cushing disease.
[4]. If it is due to adrenal origin it is called Cushing syndrome. Generally, these two terms are used interchangeably.
Pituitary Origin for Cushing syndrome .
[1]. Increased secretion of ACTH causes hyperplasia of adrenal cortex leading to hypersecretion of glucocorticoid.
[2]. ACTH secretion is increased by:
1. Tumor in pituitary cells, particularly in basophilic cells which secrete ACTH .
2. Malignant tumor of non-endocrine origin like cancer of lungs or abdominal viscera .
3. Hypothalamic disorder causing hypersecretion of corticotropin-releasing hormone.
Adrenal Origin for Cushing syndrome .
Cortisol secretion is increased by:
1. Tumor in zona fasciculata of adrenal cortex .
2. Carcinoma of adrenal cortex .
3. Prolonged treatment of chronic inflammatory diseases like rheumatoid arthritis, with high dose of exogenous glucocorticoids .
4. Prolonged treatment with high dose of ACTH, which stimulates adrenal cortex to secrete excess glucocorticoids.
Recently, Cushing syndrome is classified into two types :-
1. ACTH-dependent Cushing syndrome which is due to hypersecretion of ACTH .
2. ACTH-independent Cushing syndrome in which the secretion of ACTH is normal.
[2.1]. The syndrome develops due to abnormal membrane receptors for some peptides like interleukin-1, gonadotropin-releasing hormone and gastric inhibitory polypeptide in the cells of zona fasciculata. [2.2]. The binding of these peptides to the abnormal receptors increases secretion of glucocorticoids, resulting in Cushing syndrome.
[2.3]. Cushing syndrome that is developed by treatment with exogenous glucocorticoids also belongs to this type.
Signs and Symptoms of Cushing syndrome .
1. Characteristic feature of this disease is the disproportionate distribution of body fat, resulting in some abnormal features:
a. Moon face: The edematous facial appearance due to fat accumulation and retention of water and salt
b. Torso: Fat accumulation in the chest and abdomen. Arms and legs are very slim in proportion to torso (torso means trunk of the body) .
c. Buffalo hump: Due to fat deposit on the back of neck and shoulder .
d. Pot belly: Due to fat accumulation in upper abdomen .
2. Purple striae: Reddish purple stripes on abdomen due to three reasons:
a. Stretching of abdominal wall by excess subcutaneous fat .
b. Rupture of subdermal tissues due to stretching
c. Deficiency of collagen fibers due to protein depletion.
3. Thinning of extremities .
4. Thinning of skin and subcutaneous tissues due to protein depletion caused by increased catabolism of proteins .
5. Aconthosis: Skin disease characterized by darkened skin patches in certain areas such as axilla, neck and groin .
6. Pigmentation of skin, especially in ACTH dependent type due to hypersecretion of ACTH which has got melanocyte-stimulating effect .
7. Facial plethora: Facial redness .
8. Hirsutism: Heavy growth of body and facial hair .
9. Weakening of muscles because of protein depletion .
10. Bone resorption and osteoporosis due to protein depletion. Bone becomes susceptible to easy fracture .
11. Hyperglycemia due to gluconeogenesis (from proteins) and inhibition of peripheral utilization of glucose. Hyperglycemia leads to glucosuria and adrenal diabetes .
12. Hypertension by the mineralocorticoid effects of glucocorticoids – retention of sodium and water results in increase in ECF volume and blood volume, leading to hypertension .
13. Immunosuppression resulting in susceptibility for infection .
14. Poor wound healing.
Tests for Cushing Syndrome .
1. Observation of external features .
2. Determination of blood sugar and cortisol levels .
3. Analysis of urine for 17-hydroxysteroids.
Treatment for Cushing Syndrome .
[1]. Treatment depends upon the cause of the disease.
[2]. Treatment may include cortisol-inhibiting drugs, surgical removal of pituitary or adrenal tumor, radiation or chemotherapy.
Nelson syndrome .
[1]. Nelson syndrome is a disorder that develops after surgical removal of both adrenal glands.
[2]. It is because of the growth of pituitary tumor that secretes excess ACTH.
[3]. The features include headache and visual problems.
[4]. Nelson syndrome can be treated with radiation or surgical removal of the pituitary gland.
Hyperaldosteronism .
Increased secretion of aldosterone is called hyperaldosteronism.
Causes and Types of Hyperaldosteronism .
Depending upon the causes, hyperaldosteronism is classified into two types:
1. Primary hyperaldosteronism .
2. Secondary hyperaldosteronism .
Primary Hyperaldosteronism .
[1]. Primary hyperaldosteronism is otherwise known as Conn syndrome.
[2]. It develops due to tumor in zona glomerulosa of adrenal cortex.
[3]. In primary hyperaldosteronism, edema does not occur because of escape phenomenon.
Secondary Hyperaldosteronism .
Secondary hyperaldosteronism occurs due to extra adrenal causes such as:
1. Congestive cardiac failure .
2. Nephrosis .
3. Toxemia of pregnancy .
4. Cirrhosis of liver.
Signs and Symptoms .
1. Increase in ECF volume and blood volume
2. Hypertension due to increase in ECF volume and blood volume .
3. Severe depletion of potassium, which causes renal damage. The kidneys fail to produce concentrated urine. It leads to polyuria and polydipsia .
4. Muscular weakness due to potassium depletion .
5. Metabolic alkalosis due to secretion of large amount of hydrogen ions into the renal tubules. Metabolic alkalosis reduces blood calcium level causing tetany.
Adrenogenital Syndrome .
[1]. Under normal conditions, adrenal cortex secretes small quantities of androgens which do not have any significant effect on sex organs or sexual function.
[2]. However, secretion of abnormal quantities of adrenal androgens develops adrenogenital syndrome. [3]. Testosterone is responsible for the androgenic activity in adrenogenital syndrome.
Causes of Adrenogenital syndrome .
Adrenogenital syndrome is due to the tumor of zona reticularis in adrenal cortex.
Symptoms of Adrenogenital syndrome .
Adrenogenital syndrome is characterized by the tendency for the development of secondary sexual character of opposite sex.
Symptoms in females .
[1]. Increased secretion of androgens causes development of male secondary sexual characters.
[2]. The condition is called adrenal virilism.
[3]. Symptoms are:
1. Masculinization due to increased muscular growth .
2. Deepening of voice .
3. Amenorrhea .
4. Enlargement of clitoris .
5. Male type of hair growth.
Symptoms in males .
[1]. Sometimes, the tumor of estrogen secreting cells produces more than normal quantity of estrogens in males.
[2]. It produces some symptoms such as:
1. Feminization .
2. Gynecomastia (enlargement of breast) .
3. Atrophy of testis .
4. Loss of interest in women.
Hyposecretion of Adrenal Cortex .
Hyposecretion of adrenocortical hormones leads to the following conditions:
1. Addison disease or chronic adrenal insufficiency .
2. Congenital adrenal hyperplasia.
Addison Disease or Chronic Adrenal Insufficiency .
Addison disease is the failure of adrenal cortex to secrete corticosteroids.
Types of Addison Disease .
1. Primary Addison disease due to adrenal cause .
2. Secondary Addison disease due to failure of anterior pituitary to secrete ACTH .
3. Tertiary Addison disease due failure of hypothalamus to secrete corticotropin-releasing factor (CRF).
Causes for Primary Addison Disease .
1. Atrophy of adrenal cortex due to autoimmune diseases .
2. Destruction of the gland because of tuberculosis .
3. Destruction of hormone-secreting cells in adrenal cortex by malignant tissues .
4. Congenital failure to secrete cortisol .
5. Adrenalectomy and failure to take hormone therapy.
Signs and Symptoms of Addison Disease .
[1]. Signs and symptoms develop in Addison disease because of deficiency of both cortisol and aldosterone.
[2]. Common signs and symptom are:
1. Pigmentation of skin and mucous membrane due to excess ACTH secretion, induced by cortisol deficiency. ACTH causes pigmentation by its melanocyte-stimulating action .
2. Muscular weakness .
3. Dehydration with loss of sodium .
4. Hypotension .
5. Decreased cardiac output and decreased workload of the heart, leading to decrease in size of the heart .
6. Hypoglycemia .
7. Nausea, vomiting and diarrhea. Prolonged vomiting and diarrhea cause dehydration and loss of body weight .
8. Susceptibility to any type of infection .
9. Inability to withstand any stress, resulting in Addisonian crisis .
Tests for Addison Disease .
1. Measurement of blood level of cortisol and aldosterone .
2. Measurement of amount of steroids excreted in urine.
Addisonian Crisis or Adrenal Crisis or Acute Adrenal Insufficiency .
[1]. Adrenal crisis is a common symptom of Addison disease characterized by sudden collapse associated with an increase in need for large quantities of glucocorticoids.
[2]. The condition becomes fatal if not treated in time.
Causes of Adrenal crisis .
1. Exposure to even mild stress .
2. Hypoglycemia due to fasting .
3. Trauma .
4. Surgical operation .
5. Sudden withdrawal of glucocorticoid treatment.
Congenital Adrenal Hyperplasia .
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| Congenital adrenal hyperplasia . |
[1]. Congenital adrenal hyperplasia is a congenital disorder, characterized by increase in size of adrenal cortex.
[2]. Size increases due to abnormal increase in the number of steroid-secreting cortical cells.
Causes of Congenital adrenal hyperplasia .
[1]. Even though the size of the gland increases, cortisol secretion decreases. It is because of the congenital deficiency of the enzymes necessary for the synthesis of cortisol, particularly, 21-hydroxylase.
[2]. Lack of this enzyme reduces the synthesis of cortisol, resulting in ACTH secretion from pituitary by feedback mechanism.
[3]. ACTH stimulates the adrenal cortex causing hyperplasia, with accumulation of lipid droplets. Hence, it is also called congenital lipid adrenal hyperplasia.
[4]. Cortisol cannot be synthesized because of lack of 21-hydroxylase.
[5]. Therefore, due to the constant simulation of adrenal cortex by ACTH, the secretion of androgens increases. It results in sexual abnormalities such as virilism.
Symptoms of Congenital adrenal hyperplasia .
In boys .
Adrenal hyperplasia produces a condition known as macrogenitosomia praecox .
Features of macrogenitosomia praecox .
1. Precocious body growth, causing stocky appearance called infant Hercules
2. Precocious sexual development with enlarged penis even at the age of 4 years.
In girls .
[1]. In girls, adrenal hyperplasia produces masculinization. It is otherwise called virilism.
[2]. In some cases of genetic disorders, the female child is born with external genitalia of male type. This condition is called pseudohermaphroditism .
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