Flashcards in 160b Ca/PO4/Bone pharm Deck (37):
what form of serum calcium is active?
50% of serum calcium (rest is bound to proteins)
What percentage of Ca from the diet is absorbed in the intestine?
How is calcium absorbed in the intestine?
1) passive diffusion throughout
2) Vit-D controlled in proximal duodenum (+ PO4)
What effect do glucocorticoids have on Ca absorption in the intestine?
diuertics: thiazide vs furosemide and Ca
loops (furosemide) lose Ca to urine
thiazides save Ca from urine
what increases PO4 excretion in the kidney?
FGF-23 and PTH
axial bone vs appendicular
axial - highly trabecular with more marrow and fat
affected with Ca diseases
osteoclast - from what cell type?
from precursor monocyte (also gives rise to macrophages)
what ligand controls osteoclast differentiation?
osteoblasts --> RANKL cytokine --> increases fusion, activity, survival via RANK on osteoclast
osteoprotegerin - function?
Blocks RANKL activity thus decreasing OC activity
osteoblast - markers for activity?
OB - from what cell type?
pluripotent precursor which also makes adipocytes
what signals activate OB?
sclerostin - what makes it and fxn?
--I wnt signals and OB differentiation --> blocks bone formation
osteoporosis - basic disease process?
OB can't keep up with increases OC activity
pagets disease of bone - basic disease process?
local increased OC activity followed by disordered OB activity --> abnormal bone
vitamin D - active form
1,25 (OH)2 D3 aka calcitriol
what is the storage form of Vit D
25 (OH) vit D --> measure this when testing for Vit D deficiency, not 1,25 form
1a-hydroxylation - where does it occur? what is made?
makes calcitriol (1,25 (OH)2 Vit D)
calcitriol receptors type? fxn?
steroid --> nuclear receptors
calcitriol effect on PTH?
decreases PTH secretion
alphacalcidol -Rx? form?
Rx - 2ndary hyper PTH from renal disease
1-OH vit D -- converted via liver to active form
calcipotriol - topical
psoriases treatment to increase cell differentiation
teriparatide - what is it? Rx? dosing? SE?
PTH analog with full activity (1st 34 aa of PTH_
Rx for osteoporosis --> anabolic
once a day = intermittent affect (anabolic)
PTH secretion pattern normally?
pulsatile manner --> anabolic effect
what decreases PTH secretion?
cinacalcet - what is it? what does it treat?
calcimimetic --> allosteric activator of CaSR (increases sensitivity to Ca)
suppresses excess PTH secretion
PTH - continuous exposure vs intermittent?
continuous - bone resorption from increased RANKL expression on OB
intermittent - bone formation via decreased OB apoptosis, suppresses sclerostin
PTHrP - what is? what can it cause?
8 of first 13 aa like PTH
can cause hypercalcemia in cancers
calcitonin - from what? what causes releases? what does it do? Rx for what?
c-cells of thyroid gland
increased secretion by high Ca
inhibits bone resorption on OC
Rx - Paget's disease
calcitonin gene related peptide
potent vasodilator in migraines
estrogen effect on bone?
--I RANKL and IL-6 --> blocks resorption
androgen effect on bone?
aromatased to estrogen
selective estrogen response modulators (SERMS)
acts as estrogen on bone but anti-estorgen effect elsewhere (mammary gland)
analogs of pyrophosphate --> interfere with OC action
Rx- osteoporosis, paget's, hypercalcemia, metastases
human monoclonal AB --I RANKL
Rx- osteoporosis and bone metastases