<prompt> An increase in LDH-5 enzyme is seen in the following except:Malignancies of CNSMuscular dystrophiesBreast carcinomaPulmonary embolism  <response>: Ans. D. Pulmonary embolismLactate dehydrogenase converts Pyruvic Acid to Lactic Acid. It has 5 Isoenzymes. Isoenzymes are the physically distinct forms of the same enzyme but catalyze the same reaction and differ from each other structurally, electrophoretically and immunologically. LDH-1 and LDH-2 rises in myocardial infarction and LDH-5 increases in liver diseases, breast carcinoma, prostate carcinoma and malignancies of CNS.TypePolypeptide ChainsElectrophoretic mobilityTissue rich in Isoenzyme typeLDH-1H4 Fastest movingFound in myocardium.LDH-2H3 M LDH-3H2 M2 LDH-4HM3 LDH-5M4 Slowest movingFound in Liver 