Question

which ldh isoenzyme fractions are for pulmonary congestion?
fraction 1 and 3
fraction 2 and 3
fraction 2 and 4
fraction 1 and 5

Explanation:

LDH (lactate dehydrogenase) has five isoenzymes. In pulmonary congestion, LDH - 2 (heart and red blood cells, also present in lungs to some extent) and LDH - 3 (found in tissues like lungs, placenta, pancreas etc.) are relevant. LDH - 1 is mainly from heart and red blood cells (more specific to heart in some cases like myocardial infarction), LDH - 4 and LDH - 5 are more related to liver and skeletal muscle.

Answer:

Fraction 2 and 3