Year 2 Endocrinology
Lecture 1: Hyposecretion of Anterior Pituitary Hormones
· Primary endocrine gland disease – disorder of an endocrine gland (e.g. thyroid, gonads, adrenal cortex), resulting in deficiency/excess of the primary hormone.
· Secondary endocrine gland disease – disorder of the anterior pituitary, so the stimulating anterior pituitary hormone is deficient/in excess.
· Tertiary endocrine gland disease – disorder of the hypothalamus, so the releasing/inhibiting hormone is deficient/in excess.
Hypopituitarism – decreased production of all anterior pituitary hormones (pan-hypopituitarism) or of specific hormones.
· Congenital (developmental defects) and gene mutations (e.g. PROP1 Mutations) are both rare causes.
· In adults, progressive loss of pituitary secretion often (but not invariably) in the following order:
o Gonadotrophins (LH and FSH)
o (Prolactin deficiency is uncommon, unrecognised?)
· Includes Simmond’s disease, Sheehan’s syndrome and pituitary apoplexy.
· Insidious in onset
o Infiltrative processes (e.g. lymphocytic)
o Pituitary adenomas
o Cranial injury
o Following surgery
· Symptoms, due to decreased thyroidal, adrenal and gonadal function:
o Secondary amenorrhoea or oligomenorrhoea (in women)
o Impotence (in men)
o Loss of libido
o Waxy skin
o Loss of body hair
o Hypotension, etc.
o basal plasma values of pituitary or target endocrine gland hormones.
o Particularly useful of measured after a ‘stimulation’ (or ‘provocation’) test. E.g. combined function tests, involving rapid sequential IV administration of GHRH, CRH, GnRH, and TRH.
o Specific tests can…