167b Mg Flashcards Preview

Endocrine - DVR > 167b Mg > Flashcards

Flashcards in 167b Mg Deck (14):
1

Mg - fxns

very widespread fxns

enzyme fxn (ATP, GTP); membrane fxn; antomic structure

2

Mg - locaiton in body

mostly intracellular

3

Mg - serum ionized Mg reflects what?

intracellular Mg

not related to total Mg (which is what is measured)

4

Mg - dry vs wet

dry = smallest
wet = largest ion

5

Mg - aq solution and fxn

very rigid structure in water - 2 layer h2o shell

perfect for binding for ATP - stablizes it and helps hydrolyses during enzyme rxns

anyting that is driven by ATP required Mg as a cofactor

6

MgSO4 and torsade de pointes

long QT --> polymorphic VT

Mg regulates the delayed potassium rectifier channel (ether a go go channel)

modulates voltage-dependent activation of channel

7

Mg and renal K wasting

Mg inhibits ROMK (aldosterone K channel)

thus Mg inhibits K loss in urine

hypoMg acts like aldosterone

8

Mg and prenancy

preg chicks loss intracellar Mg

needed to regulate SBP (inverse corelation)

9

hyperMg

low RR

cause is iatrogenesis

10

Mg and CV Risk

low Mg reduces Na/K ATPase

increases intraceullarl Na and decreases K

high Mg = lower CV risk

11

Mg and Ca channel

Mg blocks influx of Ca --> hypo causes vasoconstriciton

high Mg = lower blood pressure

12

Mg and insulin

Mg --> activates tyrosine kinase --> P insulin receptor --> increased insulin sensitivity

(hypoMg --> metabolic syndrome)

13

Mg balance and alcoholism

alcohol increases Mg loss
diuretics
cyclosporin

14

problem with Mg-oxide?

no bioavailabilty