MAGNESIUM

Question 1

DIVALENT CATION (Mg2+)
2ND MAJOR INTRACELLULAR CATION

Answer 1

MAGNESIUM

Question 2

Involved in neuromuscular conduction, enzyme phosphorylation, and protein anabolism
MAINLY DERIVED FROM DIET (Exogenous source)

Answer 2

MAGNESIUM

Question 3

Distribution of Magnesium
o Bone:

Answer 3

53%

Question 4

Distribution of Magnesium
o Muscle and other organs and soft tissues:

Answer 4

46%

Question 5

Distribution of Magnesium
Serum and RBC:

Answer 5

<1%

Question 6

Forms of Magnesium in serum
o Protein Bound:

Answer 6

33%

Question 7

Forms of Magnesium in serum
o Free or ionized:

Answer 7

61% (physiologically ACTIVE FORM)

Question 8

Forms of Magnesium in serum
o Complexed with PO4- and citrate:

Answer 8

6%

Question 9

PTH means

Answer 9

parathyroid hormone

Question 10

Produced by parathyroid gland

Answer 10

parathyroid hormone

Question 11

Responsible for the increase renal reabsorption of magnesium

Answer 11

parathyroid hormone

Question 12

T/F. PTH, Increases the intestinal absorption of Mg2+ because it can also be derived from the diet

Answer 12

True

Question 13

T/F. PTH activity is INVERSELY PROPORTIONAL to the calcium & magnesium level in the blood

Answer 13

False, DIRECTLY PROPORTIONAL

Question 14

T4 means

Answer 14

Aldosterone and thyroxine

Question 15

T/F. Aldosterone and thyroxine (T4), promotes ↑ RENAL EXCRETION of magnesium and calcium

Answer 15

True

Question 16

T/F. Aldosterone and thyroxine (T4), promotes sodium absorption

Answer 16

True

Question 17

Normal range of Magnesium

Answer 17

0.63-1.0 mmol/L or 1.26-2.10 mEq/L

Question 18

T/F. Normal level of Mg is HIGHER compared with Na+ & Cl-

Answer 18

False, Normal level is LOWER

Question 19

CAUSES OF HYPOMAGNESEMIA

Answer 19

Reduced Intake
Decreased Absorption
Others

Question 20

Causes of Reduced Intake

Answer 20

Poor diet/starvation
Prolonged Mg+ - deficient IV
Chronic Alcoholism

Question 21

Causes of Decreased Absorption

Answer 21

Malabsorption Syndrome
Pancreatitis, Diarrhea
Vomiting, Laxative use, etc.
Neonatal – due to surgery
Primary – selective malabsorption
Congenital – transport defect in SI

Question 22

Other Causes of HYPOMAGNESEMIA

Answer 22

Excess Lactation
Pregnancy (developing fetus)

Question 23

CAUSES OF HYPOMAGNESEMIA (DUE TO INCREASED EXCRETION)

Answer 23

Renal
Endocrine
Drug Induced

Question 24

Causes of Renal

Answer 24

Tubular disorder, Pyelonephritis
Glomerulonephritis

Question 25

Causes of Endocrine

Answer 25

Hyperparathyroidism - ↑Ca ↓Mg Hyperaldosteronism - ↑Na ↓Mg Hyperthyroidism - ↑Mg excretion Hypercalcemia - ↑Ca ↓Mg Diabetic Ketoacidosis – glycosuria

Question 26

Causes of Drug Induced

Answer 26

Diuretics (Furosemide, Thiazide) Antibiotics (Gentamicin) Cyclosporin (Immunosuppressant) Digitalis and Digoxin (Glycosides)

Question 27

CAUSES OF HYPERMAGNESEMIA

Answer 27

↓ Excretion, acute/chronic renal failure – GFR <30 mL/min Hypoaldosteronism – ↓Na ↑Mg reabsorption ↑ Increased intake (Medications and Therapy) Dehydration – pseudo hypermagnesemia Bone carcinoma and bone metastases – due to ↑ in bone loss

Question 28

What are the tube and specimen needed for Specimen Collection of Magnesium?

Answer 28

Serum, Plasma (Lithium heparin), 24-hour urine

Question 29

T/F. Hemolysis causes false ↑ as it is also found in the RBC

Answer 29

True

Question 30

REFERENCE METHOD for Mg

Answer 30

AAS

Question 31

Magnesium concentration is DIRECTLY PROPORTIONAL to the absorbance

Answer 31

COLORIMETRIC METHOD

Question 32

Reaction: Mg2+ + Calmagite → Reddish-violet (532 nm) The level of Magnesium is DIRECTLY PROPORTIONAL with the reddish-violet product

Answer 32

CALGAMITE METHOD

Question 33

Reaction: Mg2+ + Dye → colored complex (660 nm)

Answer 33

FORMAZEN DYE METHOD

Question 34

Reaction: Mg2+ + Chromogen → colored complex

Answer 34

METHYL THYMOL BLUE METHOD

Question 35

Serum will undergo deproteinization process using TCA to precipitate and remove proteins → TCA filtrate of the serum Reaction: Serum TCA filtrate + Titan Yellow → Red compound

Answer 35

TITAN YELLOW

Question 36

Reaction: Mg2+ + 8-hydroxyl-5-quinoline sulfonic acid → fluorescence (Wavelength: 380-410nm)

Answer 36

FLUOROMETRIC METHOD