disorders of adrenal cortex

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DISORDERS OF ADRENAL CORTEX

Lecture – 2Dr. Zahoor Ali Shaikh

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DISORDERS OF ADRENAL CORTEX Adrenal Cortex may secrete hormones in excess

[too much] or too little. We will discuss excess of hormone first : When there is increased secretion, it will cause 1. Hyperaldosteronism or Conn’s syndrome

[increased aldosterone secretion] 2. Cushing’s syndrome [excess of Cortisol hormone] 3. Adrenogenital syndrome [adrenal androgen hyper

secretion]

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HYPERALDOSTERONISM OR CONN’S SYNDROME

Aldosterone hyper secretion may occur due to aldosterone secreting tumor of adrenal cortex.

Aldosterone hyper secretion may occur due to high activity of renin angiotensin aldosterone system due to chronic reduction of arterial blood flow to the kidneys [secondary hyper- aldosteronism].

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PRIMARY HYPERALDOSTERONISM OR CONN’S SYNDROME Conn’s syndrome is characterized by - Na+ retention [hypernateremia]

- K+ [hypokalemia] - Hypertension [increased Na+ reabsorption, therefore increased ECF & blood volume]

- Decreased Renin secretion

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CUSHING’S SYNDROME Cushing’s syndrome can be caused by 1. Adrenal tumor [which secretes

increased cortisone independent of ACTH].

2. Increased ACTH secretion by anterior pituitary [called Cushing Disease].

3. ACTH secreting tumor located in places other than pituitary, most commonly in lungs.

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CUSHING’S SYNDROME Cushing’s syndrome is characterized by: - Increased Cortisol and androgen levels. - Decreased ACTH [as cortisol secretion

increased by adrenal tumor]. -NOTE : Increased ACTH occurs in pituitary tumor i.e. Cushing disease]. - Hyperglycemia [due to increased Cortisol]. - Increased protein catabolism and muscle wasting.

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CUSHING’S SYNDROME [CONT] Central obesity [abnormal fat deposition,

at face, shoulder blades and abdomen]. They are called Buffalo hump, and moon face.

Limbs remain thin. Loss of muscle protein leads to muscle

weakness and fatigue. Poor wound healing. Bruises.

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CUSHING’S SYNDROME [CONT] Striae in abdomen due to protein poor

thin skin which is over stretched by increased fat deposition.

Osteoporosis and bone fracture. Hypertension. Verilization in women [caused by

increased level of adrenal androgens].

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ADRENOGENITAL SYNDROME There is enzyme defect commonly 21–

Hydroxylase, therefore, Cortisol is not produced by adrenal cortex and there is increased ACTH.

Increased ACTH causes changes in cholesterol precursor into androgen path way.

This results in increase in DHEA [Dehydroepiandrosterone] and androgens.

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ADRENOGENITAL SYNDROME Due to increased secretion of adrenal

sex hormones which affect genitalia and are associated with sexual characteristics.

Effect of androgen will depend according to the age of patient.

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EFFECT OF HYPERSECRETION OF ADRENAL ANDROGEN ON NEW BORN FEMALE

Congenital Adrenal Hyperplasia [CAH] - 21- Hydroxylase Deficiency - Autosomal Recessive, occurs 1:15000 birth New born female with Adrenogenital syndrome

manifest ambiguous external genitalia because of increased androgen secretion occurring during early fetal life.

It is cause of female PSEUDOHERMAPHRODITISM [a condition in which ovaries are present but external genitalia resemble that of male]

NOTE – True HERMAPHRODITE has gonads of both sexes.

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EFFECT OF HYPERSECRETION OF ADRENAL ANDROGEN ON ADULT FEMALE

In adult female, hypersecretion of androgen causes male pattern of body hair called HIRSUTISM [beard].

Deepening of voice. Muscular arms and legs. Breast become smaller. Menstruation may stop (due to androgen

negative feed back on hypothalamus – pituitary – ovarian axis).

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EFFECT OF HYPERSECRETION OF ADRENAL ANDROGEN ON ADULT MALE Increased adrenal androgen secretion in

adult male has no apparent effect because masculinizing effect of DHEA is weak in face of powerful masculinizing effect of testosterone.

NOTE – Increased androgen inhibit gonadotropins but not ACTH, therefore, adult patient with Adrenogenital syndrome are sterile [no children].

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SUMMARY In Adrenogenital syndrome, we get symptoms

according to the age, in adult they are: 1. Symptoms of adrenal virilization 2. Sterility 3. Symptoms of Cortisol deficiency

TREATMENT – Glucocorticoids [Cortisol] It reverses the virilization, sterility and Cortisol

deficiency by blocking the effect of ACTH.

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WE WILL DISCUSS EFFECT OF LESS SECRETION OF HORMONES BY ADRENAL CORTEX

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PRIMARY ADREONOCORTICAL INSUFFICIENCY OR ADDISON’S DISEASE

Addison’s Disease or Primary Adrenocortical Insufficiency

Causes – Autoimmune disease – 90%, causing

destruction of adrenal cortex, therefore, aldosterone, Cortisol and sex hormone are deficient, there is increased ACTH.

- Tuberculosis – 10%

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SECONDARY ADRENOCORTICAL INSUFFICIENCY

Secondary Adrenocortical insufficiency. - Due to pituitary or hypothalamic

abnormality causing decreased ACTH secretion.

- In this case, only Cortisol and sex hormone are deficient but aldosterone secretion is not affected as it does not depend on ACTH.

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ADDISON’S DISEASE Incidence 3-4 per million per year. It is characterized by - decreased Na+[Hyponatremia] - increased K+ [hyperkalemia] - decreased blood pressure - decreased blood glucose

[hypoglycemia]

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ADDISON’S DISEASE [CONT]

- weight loss, weakness - metabolic acidosis [due to

aldosterone deficiency causing decreased secretion of H+ ion]

- hyper pigmentation [due to increased ACTH. ACTH contains MSH- melanocyte stimulating hormone effect]

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SECONDARY ADRENOCORTICAL INSUFFICIENCY

It is due to pituitary disease, therefore, there is deficiency of ACTH.

There is no hyper-pigmentation. Aldosterone level is normal, therefore

Na+, and K+ changes do not occur.

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WHAT DO YOU KNOW FROM THIS LECTURE?

Conn’s Syndrome or Hyperaldosteronism Cushing’s Syndrome [Cortisol Hyper Secretion] Cushing Disease Adrenogenital Syndrome [Adrenal Androgen

Hyper Secretion] Addison’s Disease [Primary Adrenocortical

Insufficiency] Secondary Adrenocortical Insufficiency [Due to

Pituitary or Hypothalamic Abnormality]

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