hypersecretion of anterior piuitary hormones Flashcards

1
Q

what is hyperpituitarism usually due to?

A
  • isolated pituitary tumours

- can also be ectopic

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2
Q

what is hyperpituitarism associated with?

A
  • visual field defects

- both eyes may be affected by bitemporal hemianopia as decussation of nerves is at optic chiasm

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3
Q

what does an excess of _____ cause?

  • ACTH
  • TSH
  • LH, FSH
  • prolactin
  • GH
A
  • ACTH = Cushing’s
  • TSH = Thyrotoxicosis
  • LH, FSH = precocious puberty in children
  • prolactin = hyperprolactinaemia
  • GH = gigantism, acromegaly
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4
Q

what are the physiological and pathological causes of hyperprolactinaemia?

A

physiological: pregnancy, breastfeeding
pathological: prolactinoma

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5
Q

what are the signs and symptoms in women?

A
  • galactorrhoea
  • secondary ammenorrhoea/oligomenorrhoea
  • loss of libido
  • infertility
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6
Q

what are the signs and symptoms in men?

A
  • galactorrhoea uncommon
  • erectile dysfunction
  • loss of libido
  • infertility
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7
Q

what is the pathophysiology of treatment?

A

dopamine from dopaminergic neurones binds to D2 receptors on lactotrophs
switches off prolactin secretion

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8
Q

how do D2 receptor agonists work?

A
  • drugs deliverately inhibit prolactin release

- dec. prolactin secretion and reduce tumour size

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9
Q

what are the side effects of these drugs?

A
  • nausea/emesis
  • postural hypotension
    dyskinesia
  • depression
  • pathological gambling
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10
Q

name 2 D2 receptor agonists

A
  • bromocriptine

- cabergoline

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11
Q

what is excess GH called in children and adults?

A
childhood = gigantism
adulthood = acromegaly
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12
Q

describe the progression of acromegaly

A

insidious

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13
Q

what happens when acromegaly is untreated?

A

associated with inc. morbidity, mortality

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14
Q

what grows in acromegaly?

A
  • periosteal bone
  • cartilage
  • fibrous tissue
  • connective tissue
  • internal organs
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15
Q

what are the clinical features of acromegaly?

A
  • excessive sweating
  • headache
  • supraoribital ridge enlargement
  • big nose
  • big hands and feet
  • thickened lips
  • macroglossia
  • prognathism (protrusion of lower jaw)
  • carpal tunnel syndrome
  • barrel chest
  • kyphosis
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16
Q

how does acromegaly lead to the development of diabetes mellitus?

A
  • excess GH
  • inhibits insulin
  • inc. insulin resistance
  • impaired glucose tolerance
  • diabetes mellitus
17
Q

what are the complications of acromegaly?

A
  • OSA: inc. soft tissue growth in throat
  • hypertension: GH mediated NA reabsorption
  • cardiomyopathy
  • cancer
  • prolactin often high
18
Q

how do you diagnose acromegaly?

A
  • GH pulsatile so random measurement is unhelpful
  • after oral glucose load, GH should drop in healhy person as insulin rises
  • but in acromegaly, there is a paradoxical rise of GH
19
Q

what is the first line treatment of acromegaly?

A

surgery

trans-sphenoidal entry

20
Q

what is the medical treatment of acromegaly?

A
  • somatostatin analogues (endocrine cyanide) e.g. octreotide

- dopamine agonists e.g. cabergoline

21
Q

what are the GI side effects?

A

nausea
diarrhoea
gallstones