Anterior Pituitary Hormones and Disorders

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).

Disorders of Anterior Pituitary

Anterior Pituitary Hormones and Disorders

  • 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 causesPituitary 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.

 

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