NEET PG Medical – 2018 – Question – 46
Which best explains “Flipping effect”?
a) LDH 1 > LDH 2
b) LDH2 > LDH1
c) LDH 2 > LDH 3
d) LDH 3 > LDH 2
Show Answer
Correct Answer – A
Answer: A – LDH 1 > LDH 2
Lactate dehydrogenase, tetrameric enzyme with 4 subunits, 4 Subunits with 2 isoforms – H isoform (Heart) & M isoform
(Muscle)
Heart & RBCs – LDH-1 (4H);
- Reticuloendothelial system – LDH-2 (3H1M)
- Lungs – LDH-3 (2H2M)
- Kidneys, placenta, & pancreas – LDH-4 (1H3M)
- Liver & striated muscle – LDH-5 (4M)
Uses: - LDH levels are more in RBC
- Helpful in assessment of Hemolysis / Tissue breakdown
Flipping effect: - Usually LDH 2 in predominant in serum & LDH 1 is predominant in heart
- Higher levels of LDH 1 than LDH 2 (Flipped pattern) is suggestive of myocardial infarction
- Damaged cardiac tissues release LDH 1 into bloodstream.
