Fig. 4. Activity of lactate dehydrogenase  (A ), creatine kinase  (B ), myoglobin  (C ), creatine kinase–muscle and brain subunit  (D ), and N-terminal pro brain natriuretic brain peptide  (E ) in plasma obtained from pigs after cardiopulmonary bypass (CPB), CPB + carbon monoxide (CO), and CPB + CO + tin protoporphyrin IX (SnPP IX) and time-matched control group (SHAM) animals. Data represent mean ± SD. *  P < 0.05, CPB  versus SHAM and  versus CPB + CO. #  P < 0.001, CPB + CO + SNPP IX  versus CPB + CO.