Kruse: hypothalamic and pituitary hormones Flashcards
Growth hormone
Somatropin
IGF-1 agonist
Mescasermin
Somatostatin analogs
- Octreotide
- Lanreotide
GH antagonist
Pegvisomant
Dopamine agonists
- Bromocriptine
- Cabergoline
Vasopressin receptor agonists
- Vasopressin
- Desmopressin
Vasopressin receptor antagonist
- Conivaptan
- Tolvaptan
Anterior pituitary hormones are negatively regulated by what hypothalamic peptides and catecholamines?
- Somatostatin
- dopamine
These are single chain protein hormones that activate kinase linked receptors of the JAK/STAT superfamily
GH and prolactin
These are dimeric proteins that activate G protein couples receptors
- TSH
- FSH
- LH
This is a single peptide cleaved from a larger precursor contains the peptide B-endorphin that also binds GPCRs
ACTH
Growth hormone production is stimulated by GHRH and inhibited by what?
peptide somatostatin (SST)
Prolactin is inhibited by dopamine via what receptor?
D2
Disruption of the pituitary stalk and the hypothalamohypophysial portal vessels will do what to prolactin?
What happens to rest of the anterior pituitary hormones?
increase
decrease
Syndromes where you can use GH
- Prader Willi
- Turner
- Noonan
other uses for GH
- Wasting in patients with AIDS
- Patients with short bowel syndrome who are dependent on total parenteral nutrition
GH toxicity and contraindication
- Rare in children: intracranial HTN (vision changes, headache, nausea, vomiting), scoliosis, otitis media in patients with Turner syndrome, hypothyroidism, pancreatitis, gynecomastia
- Adults: peripheral edema, myalgias, arthralgias, carpal tunnel syndrome
- Contraindicated in patients with a known malignancy
A small number of children with growth failure have severe IGF-1 deficiency that is not responsive to exogenous GH due to what?
mutations in GH receptor and development of neutralizing antibodies to GH
What is mecasermin a complex of
rhIGF-1 and rhIGFBP-3 (this is needed to increase half life of rhIGF-1)
Mecasermin is administered how
SQ
most common adverse effect of Mecasermin
-hypoglycemia: eating 20 minutes before administration prevents this
What is the most widely used SST analog
Octreotide
Octreotide reduces what symptoms associated with hormone secreting tumors?
- Acromegaly
- Carcinoid syndrome
- Gastrinoma
- Glucagonoma
- Nesidioblastosis
- diabetic diarrhea
- watery diarrhea
- hypokalemia
- achlorhydria (WDHA) syndrome
Lanreotide is approved for treatment of what?
acromegaly
Adverse effects of SST analogs
- GI
- Gallbladder sludge and gallstones
- Cardiac effects (sinus bradycardia, conduction disturbances)
- vitamin B12 deficiency
What is Pegvisomant used to treat
Acromegaly
Toxicity and contraindications for Dopamine agonists?
- nausea, headache, light headedness, orthostatic hypotension, fatigue are most common
- Psychiatric manifestation
- Pulmonary infiltrated may occur with chronic high dose
- Patients with MACROadenoma and pregnant . .continue
- if MICRO then discontinue
- Dopamine agonists are not recommended to suppress postpartum lactation due to increased incidence of stroke or coronary thrombosis
Receptors for vasopressin
- V1: vascular smooth muscle cells –> vasoconstriction
- V2: renal tubule cells –> reduce diuresis through increased water permeability and water resorption n collecting tubules
- Extrarenal V2 . . release of coagulation factor VIII and vWF
What is preferred for central diabetes insipidus, Desmopressin or vasopress
Desmopressin . . due to selectivity for V2
When is desmopressin used
treatment of coagulopathy in hemophilia A and Von Willebrand disease
Toxicity and contraindications for Vasopressin and desmopressin
- headache, nausea, abdominal cramps, agitation, and allergic reactions occur rarely
- Overdose: hyponatremia and seizures
- Vasopressin should be used with caution in patients with coronary artery disease due to vasoconstriction
Which vasopressin Antagonist is selective for V2?
Which binds to both?
- Tolvaptan
- Conivaptan
Metabolism of vasopressin antagonists?
CYP3A4
