160b Ca/PO4/Bone pharm Flashcards Preview

Endocrine - DVR > 160b Ca/PO4/Bone pharm > Flashcards

Flashcards in 160b Ca/PO4/Bone pharm Deck (37):
1

what form of serum calcium is active?

ionized only

50% of serum calcium (rest is bound to proteins)

2

What percentage of Ca from the diet is absorbed in the intestine?

10-20% absorbed

3

How is calcium absorbed in the intestine?

1) passive diffusion throughout

2) Vit-D controlled in proximal duodenum (+ PO4)

4

What effect do glucocorticoids have on Ca absorption in the intestine?

Reduce

5

diuertics: thiazide vs furosemide and Ca

loops (furosemide) lose Ca to urine

thiazides save Ca from urine

6

what increases PO4 excretion in the kidney?

FGF-23 and PTH

7

axial bone vs appendicular

axial - highly trabecular with more marrow and fat
affected with Ca diseases

8

osteoclast - from what cell type?

from precursor monocyte (also gives rise to macrophages)

9

what ligand controls osteoclast differentiation?

osteoblasts --> RANKL cytokine --> increases fusion, activity, survival via RANK on osteoclast

10

osteoprotegerin - function?

Blocks RANKL activity thus decreasing OC activity

11

osteoblast - markers for activity?

osteocalcin
alkaline phosphatase

12

OB - from what cell type?

pluripotent precursor which also makes adipocytes

13

what signals activate OB?

IGF-1
wnt pathway

14

sclerostin - what makes it and fxn?

Osteocytes

--I wnt signals and OB differentiation --> blocks bone formation

15

osteoporosis - basic disease process?

OB can't keep up with increases OC activity

16

pagets disease of bone - basic disease process?

local increased OC activity followed by disordered OB activity --> abnormal bone

17

vitamin D - active form

1,25 (OH)2 D3 aka calcitriol

18

what is the storage form of Vit D

25 (OH) vit D --> measure this when testing for Vit D deficiency, not 1,25 form

19

1a-hydroxylation - where does it occur? what is made?

kidney

makes calcitriol (1,25 (OH)2 Vit D)

20

calcitriol receptors type? fxn?

steroid --> nuclear receptors

increases transcription

21

calcitriol effect on PTH?

decreases PTH secretion

22

alphacalcidol -Rx? form?

Rx - 2ndary hyper PTH from renal disease

1-OH vit D -- converted via liver to active form

23

calcipotriol - topical

psoriases treatment to increase cell differentiation

24

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)

osteosarcoma?

25

PTH secretion pattern normally?

pulsatile manner --> anabolic effect

26

what decreases PTH secretion?

calcimimetics
Ca
Vit-D

27

cinacalcet - what is it? what does it treat?

calcimimetic --> allosteric activator of CaSR (increases sensitivity to Ca)

suppresses excess PTH secretion

28

PTH - continuous exposure vs intermittent?

continuous - bone resorption from increased RANKL expression on OB

intermittent - bone formation via decreased OB apoptosis, suppresses sclerostin

29

PTHrP - what is? what can it cause?

8 of first 13 aa like PTH

can cause hypercalcemia in cancers

30

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

31

CGRP

calcitonin gene related peptide

potent vasodilator in migraines

32

estrogen effect on bone?

--I RANKL and IL-6 --> blocks resorption

osteoclast apoptosis

33

androgen effect on bone?

aromatased to estrogen

34

raloxifene

selective estrogen response modulators (SERMS)

acts as estrogen on bone but anti-estorgen effect elsewhere (mammary gland)

35

bisphosphonates

alendronate
_dronate

analogs of pyrophosphate --> interfere with OC action

Rx- osteoporosis, paget's, hypercalcemia, metastases

36

denosumab

human monoclonal AB --I RANKL

inhibits osteoclast

Rx- osteoporosis and bone metastases

37

what is the only anabolic bone Rx?

teriparatide