Magnesium Flashcards
Which mineral is a divalent cation and ranked 6 in overall abundance in the body?
magnesium (Mg)
- 55-60 % found in bone
What are 3 foods high in magnesium?
nuts, legumes, and whole-grains
Intracellular magnesium is second only to what mineral?
potassium
Where is magnesium absorbed?
small intestine
What are the two brush boarder transports for magnesium?
- transient receptor potential M6 (TRPM6)
2. paracellular diffusion
The basolateral border uses what system?
Na/Mg ATPase antiport system
What 4 things inhibit magnesium absorption?
- phytates and fiber
- unabsorbed fatty acids –> soaps
- Mg - Phosphorus complexes
- zinc - competes with Mg absorption
What mineral competes with magnesium for absorption?
zinc
How does PTH increase magnesium absorption?
by increasing TRPM6 concentrations
What are the plasma membrane magnesium transports, and where are they found?
- magnesium transporter 1 (MagT1) –> epithelial cells
2. TRPM7 –> bone, heart, and adipose tissue
What % of the body’s magnesium is found in the bone?
55-60 %
Up to 90 % of intracellular magnesium is involved with what type of enzymes?
ATP or ADP associated enzymes
- magnesium is required for the majority of the 518 known human kinases
What mineral is required for insulin sensitivity, and what enzyme is involved?
magnesium
- cofactor for Tryosine kinase
What mineral is a cofactor for tyrosine kinase?
magnesium
Magnesium is a cofactor for what enzyme that is required for insulin sensitivity?
tyrosine kinase
There is an inverse relationship between type 2 diabetes and which mineral?
magnesium
Magnesium depletion is common in what group?
diabetics
- due to excessive Mg urinary excretion
What are the 5 enzymes that require magnesium?
- transketolase
- glutamylcysteine synthetase
- glutathione synthetase
- DNA polymerase
- RNA polymerase
Magnesium activates pyruvate dehydrogenase phosphatase and inhibits pyruvate dehydrogenase kinase, which in turn will up-regulate what?
the oxidative decarboxylation of E1 complex
The oxidative decarboxylation of E1 complex is up-regulated by what mineral?
magnesium
How does magnesium function in transmembrane communication and ion channels?
- membrane stabilization
- second messenger systems
- ion channels
Adenylate cyclase and Na/K-ATPase pump is activated by what mineral?
magnesium
What mineral is needed for PTH effects on bone, kidney, and GI tract?
magnesium
Magnesium is required for the hydroxylation of what vitamin?
vitamin D by 25-hydroxylase
- vit D deficiency also requires magnesium supplementation
