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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61

Stimulation of prolactin release

pregnancy; estrogen; nursing; sleep; stress; low glucose; dopamine antagonists; opioids; serotonin; H2 antagonists

62

Inhibition of prolactin release

dopamine; somatostatin; GnRH-associated peptide; prolactin; GABA; high glucose

63

Describe the prolactin receptor

monomer that lacks intrinsic tyrosine kinase activity; binding of prolactin causes receptor dimerization resulting in the recruitment and activation of JAK kinases that phosphorylate JAK proteins and eventually the activation of transcription factor STAT proteins

64

Which hormones bind prolactin receptors

prolactin, growth hormone and placental lactogen

65

Half life of natural prolactin

15 - 20 minutes

66

Preparations for treating prolactin-deficient patients

there is currently no appropriate preparation available

67

Hyperprolactinemia may occur

1. as a result of various drugs (antagonists of dopamine)
2. due to disorders of hypothalamus or pituitary gland that interfere with the action of prolactin release inhibiting hormone
3. prolactin secreting pituitary tumors

68

Treatment of hyperprolactinemia

1. irradiation and surgical removal of tumor
2. prolactin-secreting tumors are treated with dopamine agonists

69

Dopamine agonists used to treat prolactin secreting tumors

quinagolide (Norprolac);
ergot derivative such as bromocriptine (Parlodel);
cabergoline (Dostinex, Cabaser)

70

How do dopamine agonists used to treat prolactin secreting tumors work?

They activate the dopaminergic (D2) receptors that are cupled to the inhibition of prolactin release in the normal anterior pituitary gland. This dopamine-inhibitor pathway is retained by prolactin-secreting pituitary tumor cells.

71

Pharmacokinetics of dopamine agonists

administered orally and circulate bound to albumin; metabolized and excreted primarily in feces (bile)

72

Toxicity and contraindications of dopamine agonists

1. Some patients experience nausea, headache, fatigue with dopamine agonist treatment
2. Nausea occurs less often with carbegoline than with bromocriptine treatment

73

Gonadotropic hormones

Follicle-stimulating hormone (FSH), Luteinizing hormone (LH)

74

Describe the structure of glycoprotein hormones of the anterior pituitary

heterodimers containing alpha and beta subunits; alpha units are identical

75

LH and FSH levels during the menstrual cycle

Plasma LH and FSH levels are highest near the time of ovulation; plasma LH and FSH levels are also high after menopause

76

Secretion of chorionic gonadotropin (CG)

CG is produced during pregnancy by fetal placenta (syncytiotrophoblaslts); enters the maternal blood and supports luteal function

77

Gonadotropic hormones (pituitary and placenta derived) are effective only when given by

injection (intramuscular and subQ)

78

Chorionic gonadotropin for injection

Pregnyl; Profasi; A.P.L.

79

How is chorionic gonadotropin hormone used clinically?

used to treat infertility in women (administer pregnyl after a series of treatments with menotropins)

80

Menotropins for injection

Menopur, Pergonal, Humegon, Repronex

81

Clinical use of menotropins

used to treat infertility in women; give low doses of pergonal daily for 7 to 12 days; give a high dose of CG preparation

82

Urofollitropin for injection

Metrodin, uFSH, Fortinex, Bravelle

83

Activity of CG

contains LH activity

84

Activity of Menotropins

contains both LH and FSH activity

85

Activity or Urofollitropin

contains only FSH activity

86

Use of Urofollitropin

exactly the same as menotropins

87

Recombinant human FSH preparations

follitropin-alpha (Gonal-F) and follitropin - beta (Puregon, Follistim)

88

Recombinant human LH preparations

rhLH; Lutropin alfa; Luveris

89

Recombinant human LH approved for use in

in women with LH deficiency - in combination with follitropin-alpha

90

Recombinant Human Chorionic Gonadotropin (rhCG)

choriogonadotropin alfa (Ovidrel)