Disorders of Anterior PituitaryHormones

The anterior pituitary is called the master gland be­ , it regulates the function of most other endocrine organs. The anterior pituitary gla’nd produces 6 major hor­mones.

1. 1, Prolactin (PRL)
2. 2. Growth hormone (GH)
3. 3. Adrenocorticotropin hormone (ACTH)
4. 4. Luteinizing hormone (LH)
5. 5. Follicle stimulating hormone (FSH)
6. 6. Thyroid stimulating hormone (TSH).

• All the pituitary hormones are secreted in a pulsatile manner by the corresponding specific hypothalamic releasing factors.
• Each pituitary hormone causes specific response from the target organ / issues.
• Pituitary diseases can cause acquired or inherited hormone deficiency.
• Pituitary tumors cause hormone excess syndrome or they cause a mass effect by pressing on adjacent structures like cavernous sinuses, optic chiasma and ._ cranial nerves, and blood vessels.
• The pituitary gland has 2 lobes-anterior and poste­rior lobes.
• The posterior pituitary is also called neurohypophy­sis,
• These target organs / glands release hormones which exert a feedback inhibition on the hypothalamus and pituitary to control the bjood level of the hormones.

ANTERIOR PITUITARY IN­SUFFICIENCY

• · Hypopituitarism is due to decreased levels of anterior pituitary trophic hormones released from the hypothalamus.
• · It can also occur due to inherited diseases.
• · Acquired deficiency can result from tumors, in­flammation or vascular damage of pituitary or hypothalamus.

Developmental and genetic causes: Pituitary dysplasia –

• This is due to hypoplastic or ectopic pituitary gland.
• It can also be due to birth trauma, asphyxia and breech delivery.

Examples are:

• · Septo-optic dysplasia (hypothalamic dysfunction, cleft palate, syndactyly, ear deformity, optic at­rophy, microgenitals, anosmia).
• · Kallmann syndrome (isolated hypogonadotropic hypogonadism, associated with defects of smell, X-linked).
• · Laurence-Moon-Bardet-Bidel Syndrome (autoso­mal recessive, mental retardation, obesity, hexadactyly, syndactyly, diabetes insipidus, reti­nal degeneration).
• · Frohlich syndrome (Hypothalamic lesions, obe­sity, hyperphagia-Ieptin deficiency, hypogo­nadism).
• · Prader-Willi Syndrome (hypogonadotropic hy­pogonadism, obesity, hypotonia, mental retar­dation, diabetes mellitus).

Acquired Hypopituitarism

• Acquired causes are accidental, or neurosurgical trauma.
• Vascular causes like pituitary apoplexy. Neoplasms like pituitary adenoma, craniopharyn­gioma, metastatic tumors.
• Inflammatory diseases like sarcoidosis, amyloido­sis, tuberculosis, and irradiation.

Pituitary apoplexy

• Acute haemorrhagic damage of pituitary may occur spontaneously in a pre-existing adenoma, or post­partum as in Sheehan’s syndrome, or in diabetes, hypertension, sickle cell anaemia, or acute shock.
• During pregnancy there is enlargement of the pitu­itary, sometimes resulting in haemorrhage. Apoplexy is an emergency with hypotension, hypoglycemia, brain haemorrhage and death.
• There is severe headache, meningeal irritation, vi­sual defects, cardiovascular collapse, coma and death. CT or MRI is used for diagnosis.

Treatment of Pituitary apoplexy

• High dose glucocorticoids.
• Surgical decompression is required in patients with visual loss and coma.