Endocrine: 15.1 and 2: Ant and Post Pituitary Gland Flashcards
How is central diabetes insipidus treated?
desmopressin/DDAVP (an ADH analog)
What normally inhibits prolactin secretion?
dopamine
What is demeclocycline? What is it used to treat?
- a synthetic tetracycline abx
- tx for SIADH and hyponatremia
What will the serum osmolality level be in central diabetes insipidus?
high
This drug is a synthetic tetracycline abx used to tx for SIADH and hyponatremia.
demeclocycline
What will the urine osmolality level be in central diabetes insipidus?
low (very dilute urine)
What are the s/s of syndrome of inappropriate ADH (SIADH)? Why?
- mental status changes
- seizures
- hyponatremia
- –> neuronal swelling, cerebral edema
What kind of molecule is somatostatin (SST)? What kind of receptor does it work upon?
- a peptide- an inhibitory protein
- GPCRs
This drug is an alkylating agent used to treat CA, autoimmune diseases, and amyloidosis.
cyclophosphamide
What happens when desmopressin/DDAVP binds to V2 receptors on collecting duct cells?
aquaporin channels are translocated to the apical membrane for H2O reabsorption
What happens when desmopressin/DDAVP binds to V2 receptors on endothelial cells?
vWF is released from the Weibel-Palade bodies
What is pegvisomant? What is it used to treat?
- a GH receptor antagonist
- tx for acromegaly/gigantism
What is bitemporal hemianopsia?
mass effect pushes on optic chiasm –> visual deficits of peripheral fields in both eyes
Where does ADH act upon?
- the distal tubules
- the collecting ducts
This drug is a GH receptor antagonist used to tx acromegaly/gigantism.
What is secreted by D cells of the pancreas and gastric mucosa?
somatostatin (SST)
Growth hormone _____ glucose uptake in cells.
decreases
Too much _____ causes Cushing syndrome.
ACTH
What is the tx for syndrome of inappropriate ADH (SIADH)?
- free water restriction
- demeclocycline
Where are the hormones of the posterior pituitary synthesized?
in the hypothalamus
What other endocrine abnormality is often seen with growth hormone adenomas? Why?
- secondary diabetes
- GH decreases glucose uptake into cells
What tumor in children can cause hypopituitarism?
craniopharyngeoma
This drug is a dopamine agonist used to tx prolactinomas, Parkinsons, and neuroleptic malignant syndrome.
bromocriptine
What are the s/s of a prolactinoma in males?
- decreased libido
- HA
This drug is an ADH analog used to tx for central diabetes insipidus, bedwetting, nocturia, and vWF/factor VIII deficiency.
desmopressin/DDAVP
Name 2 places where pathology can occur to cause central diabetes insipidus.
- the hypothalamus
- the posterior pituitary
What is desmopressin? What is it used to treat?
- an ADH analog
- tx for:
- central diabetes insipidus
- bedwetting
- nocturia
- vWF/factor VIII deficiency
What does the word “diabetes” mean?
too much urination
Name a primary cause of Empty Sella Syndrome.
- arachnoid mater and CSF herniation into the sella turcica –> compression and destruction of pituitary gland
How is a growth hormone adenoma diagnosed?
- elevated GH
- elevated insulin-like growth factor 1 (IGF-1)
- lack of GH suppression by oral glucose
Name a dopamine agonist used to treat prolactinomas.
bromocriptine
What will the urine specific gravity level be in central diabetes insipidus?
low
What is syndrome of inappropriate ADH (SIADH)?
too much ADH –> retention of free water –> hyponatremia
Dx?
- too much ADH –> retention of free water –> hyponatremia
syndrome of inappropriate ADH (SIADH)
Dx?
- water deprivation test –> failure to increase urine osmolality
central diabetes insipidus
What will the serum sodium status be in syndrome of inappropriate ADH (SIADH)?
low (hyponatremia)
What are the s/s/ of Sheehan syndrome?
poor lactation, loss of pubic hair, fatigue
What is bromocriptine? What is it used for?
- a dopamine agonist
- tx for prolactinomas, Parkinsons, and neuroleptic malignant syndrome
What are the s/s of a somatostatinoma?
- ab pain
- gallstones
- constipation
- hyperglycemia
- steatorrhea
Where does endogenous SST come from?
D cells of the pancreas and gastric mucosa
Prolactin inhibits ____.
GNRH
What causes nephrogenic diabetes insipidus?
- an inherited mutation
- drugs (lithium, demeclocycline)
What is central diabetes insipidus?
ADH deficiency
What are the s/s of a prolactinoma in females?
- galactorrhea
- amenorrhea
How is central diabetes insipidus diagnosed?
water deprivation test –> failure to increase urine osmolality
Normally, ____ suppresses growth hormone secretion.
glucose
On what kind of receptor does desmopressin/DDAVP act upon?
V2
What is another name for somatostatin (SST)?
growth hormone inhibiting hormone
Too much ACTH causes _____.
Cushing syndrome
What is octreotide? What is it used to treat?
- a somatostatin (SST) analog –> blocks anterior pituitary’s response to GHRH
- tx for:
- growth hormone adenomas
- anterior pituitary adenomas
- VIP-omas
- carcinoid syndrome
How does demeclocycline work to treat syndrome of inappropriate ADH (SIADH)?
it blocks the action of ADH on the renal collecting duct
What is apoplexy?
bleeding within an organ
How is a growth hormone adenoma treated?
- octreotide
- pegvisomant (GH receptor antagonists)
- surgery
What is cyclophosphamide? What is it used to treat?
- an alkylating agent
- tx for:
- CA
- autoimmune diseases
- amyloidosis
What does somatostatin (SST) do in the GI system?
- stomach:
- reduces acid secretion by inhibiting parietal cells, gastrin, secretin, CCK, motilin, VIP, GIP, and histamine
- decreases gastric emptying and motility
- pancreas:
- inhibits insulin release
- inhibits glucagon release
Name the hormone:
- stomach:
- reduces acid secretion by inhibiting parietal cells, gastrin, secretin, CCK, motilin, VIP, GIP, and histamine
- decreases gastric emptying and motility
- pancreas:
- inhibits insulin release
- inhibits glucagon release
somatostatin (SST)
What causes syndrome of inappropriate ADH (SIADH)?
- small cell carcinoma of the lung (ADH produced)
- CNS trauma
- pulmonary infection/pathology
- drugs (cyclophosphamide)
In the liver, growth hormone acts to _____ production of insulin-like growth factor 1 (IGF-1).
increase
What will the serum sodium level be in central diabetes insipidus?
high (hypernatremia)
What will the serum osmolality be in syndrome of inappropriate ADH (SIADH)?
low (dilute)
How can central and nephrogenic diabetes insipidus be distinguished?
nephrogenic = no response to desmopressin/DDAVP
Why do pts with Sheehan syndrome lose their pubic hair?
Sheehan = pituitary infarction –> loss of LH production, which is essential for androgen synthesis stimulation
What is nephrogenic diabetes insipidus?
impaired renal response to ADH (no response to desmopressin)
