Pharmacology of Anterior Pituitary Hormones Flashcards Preview

Pharmacology Test #5 > Pharmacology of Anterior Pituitary Hormones > Flashcards

Flashcards in Pharmacology of Anterior Pituitary Hormones Deck (107)
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31

Type 1 IGF receptor binds

both IGF-1 and IGF-2 with high affinity

32

Type II IGF receptor binds

IGF-2 specifically

33

Type II IGF receptor signals

the encoding of cytoplasmic proteins that act as receptor for proteins targeted to lysosomes

34

In plasma and other body fluids, IGFs are tightly bound to

large protein carriers, the IGF-binding proteins (IGFBPs)

35

Characteristics of severe growth hormone deficiency

1. short stature and mild adiposity
2. adiposity and hypoglycemia
3. predicted adult height substantially below mean parental height
4. adnormally slow growth velocity
5. abnormally low plasma concentrations of IGF-1
6. poor responses to provocative tests for secretion of GH

36

To diagnose GH deficiency:

1. Exclude all other causes of poor growth
2. Growth rate below 4 cm/year
3. Perform provocative test

37

What is a provocative GH test?

Administer stimuli such as insulin-induced hypoglycemia, levodopa, apomorphine, agonists of serotonin and measure plasma growth hormone within 45-90 minutes - GH level of less than standard conc. indicates deficiency

38

GH replacement therapy is approved in

children with idiopathic short stature (non-hormone deficient short stature) with a height that is 2.25 deviations or more below national norm for children of same age

39

GH is approved for children with what condition

chronic renal failure

40

What does GH do in children with Prader-Willi syndrome (characterized by growth failure, low muscle tone and obesity)?

growth hormone therapy decreased body fat and increased lean body mass

41

Adults with growth hormone deficiency have

generalized obesity, reduced muscle mass, and reduced cardiac output

42

Other weird uses of growth hormone

AIDS-associated wasting and patients with short bowel syndrome dependent on TPN

43

Rapid growth with GH may cause

scoliosis in a few patients

44

Rare side effect of GH in children

intracranial hypertension, visual changes, headache and nausea

45

Side effects of GH in adults

peripheral edema, athralgias, carpal tunnel syndrome, myalgias, mild to moderate nausea and headache

46

What happens with GH treatment of critically ill patients

increases mortality

47

Mecasermin (Increlex)

recombinant human IGF-1

48

Mecasermine rinfabate (Iplex)

recombinant human IGF-1/IGFBP-3

49

Laron-type dwarfism

inheritable growth hormone resistant disease:
receptors for GH are few or absent; plasma level of biologically active GH high; low plasma IGF-1

50

IGF-1 deficient patients (Laron-type dwarfs) responds well to

Mecasermin therapy

51

Majority of acromegaly cases are caused by

growth-hormone secreted from pituitary tumors referred to as somatotrophinomas

52

In patients with non-fused ephiphysis, growth hormone excess causes

enhanced longtitudinal growth and gigantism

53

In adults, growth hormone excess causes

acromegaly with symptoms such as arthropathy, carpal tunnel syndrome, generalized visceromegaly, hypertension, headache, lethargy, excess perspiration and sleep apnea

54

Treatment of Acromegaly:

1. Growth hormone secreting pituitary tumors are treated with surgery or irradiation
2. If growth hormone hypersecretion persists, use somatostatin analogs, dopamine receptor agonists, growth hormone antagonists

55

Somatostatin analogs

1. Octreotide (Sandostatin)
2. Lanreotide (Somatuline)
3. Vapreotide
4. Pasireotide (Signifor)

56

Agonists of dopamine are potent inhibitors of

lactotroph function

57

Dopamine agonists

ergot derivative such as 2-bromo-ergocrypine (bromocriptine; Parlodel), carbegoline (Dostinex)

58

How can a dopamine agonist inhibit growth hormone secretion by pituitary tumor cells

if the growth hormone secreting tumor cells originate from lactotrophs (prolactin secreting pituitary cells)

59

Pegvisomant (Somavert)

growth hormone antagonist developed by recombinant DNA technology for the treatment of acromegaly

60

Prolactin is synthesized and stored in

pituitary cells called lactotrophs;
also synthesized by human placental tissue