Biochemistry General a639899b Damage to RBC resulting in their lysis, increases which isoenzyme in blood? A LDH-1 B LDH-3 C LDH-4 D LDH-5 High-Yield Explanation LDH 1 is pre-dominantly present in RBCs and smooth muscle of heart, thus when RBCs are damaged, LDH1 is raised.