OBJECTIVETo develop a technology for production of recombinant SAG1 of Toxoplasma gondii(T.g) in batches.

METHODSTwelve healthy mongrel dogs undergoing CPB were randomly allocated into control group (group C, n=6) and PDTC pretreatment group (group P, n=6). In group P, the dogs received intravenous injection of PDTC at 30 mg/kg before CPB, while in group C, normal saline was given instead. The myocardial tissues were obtained before CPB, 60 min after aortic cross-clamping (AC) and 60 min after declamping (DC) for determining the myocardial contents of adenine nucleotides (ATP, ADP, AMP, TAN, EC) and malondialdehyde (MDA) and evaluating the total anti-oxidation capacity (T-AOC) and mitochondrial swelling degree (MSD). The heart rate (HR), mean arterial pressure (MAP) and cardiac output (CO) were monitored before CPB, 30 min and 60 min after DC.

RESULTSIn both groups, the myocardial contents of ATP, TAN, EC and T-AOC decreased while MDA content and MSD increased after AC as compared to the values before CPB (P<0.01). In group C, ATP, TAN, EC and T-AOC decreased while MDA content and MSD increased after DC as compared to the values before CPB (P<0.01). At 60 min after DC, the dogs in group P showed no significant variation in the contents of ATP, TAN, EC, MDA, T-AOC or MSD (P>0.05). ATP, TAN, EC and T-AOC were significantly lowered while MDA and MSD increased at 60 min after AC and after DC in group P in comparison with the measurements in group C (P<0.01). HR, MAP and CO of group P recovered rapidly at 30 min and 60 min after DC as compared with those in group C (P<0.01).

CONCLUSIONCPB can induce serious energy exhaustion and delay in the recovery of energy metabolism. PDTC pretreatment can substantially ameliorate myocardial energy depletion and protect the myocardial mitochondria to attenuate myocardial ischemia/reperfusion injury.