Magnesium Flashcards
what are the two brush boarder transports (uses Na/ATPase antiport system)
- transient receptor potential M6 (TRPM6)
2. paracellular diffusion
what 4 factors inhibit absorption of magnesium
- phyates
- unabsorbed fatty acids that bind to Mg to form soaps
- phosphorus can form a complex Mg3(Po4)2 within GI
- zinc competes with Mg absorption
PTH function on magnesium
PTH increases Mg absorption only when Mg concentrations are low
what are the two transports of magnesium
- magnesium transport 1 (MagT1) in epithelial cells
2. TRPM7 in bone, heart, and adipose cells
kinases: Mg is a ______ for tyrosine kinase
cofactor (required for insulin sensitivity)
Mg depletion is common in diabetics due to
excess urinary Mg excretion
does Mg supplementation help diabetic patients control disease?
yes
5 enzymes that require magnesium
- transketolase
- glutamylcysteine synthetase
- glutathione synthetase
- DNA polymerase
- RNA polymerase
Mg up regulates the oxidative decarboxylation ____ complex
E1
what two transmembrane communication and ion channels are activated by Mg
- adenylate cyclase
2. Na/K-ATPase pump
25-hydroxylase uses Mg as a
cofactor
Mg deficiency can ___ calcium plasma concentrations
reduce
what 3 ways does Mg act as an antagonist to Ca
- inhibits release of Ca from sarcoplasmic reticulum
- competes with Ca for binding sites of troponin
- inhibits acetylcholine release and smooth muscle contraction *
Mg prevents ______ and reduces incidence of myocardial infarction or stoke
hyper coagulability
PTH ____ Mg excretion
inhibits
