OBJECTIVETo investigate the cardioprotective effects of the peptides from the velvet antler (VAP) of Cervus nippon on acute ischemic myocardial injury in rats and its underlying mechanisms.

METHODThe model rats of myocardial ischemia injury (MI) was produced by ligating the left anterior descending (LAD) branch of the coronary artery of rats. The rats were divided randomly into six groups: sham-operated group; ischemic myocardial injury (MI) model group; diltiazem hydrochloride 1 mg x kg(-1) group; VAP 30 mg x kg(-1) group; VAP 60 mg x kg(-1) group; VAP 120 mg x kg(-1) group. VAP or diltiazem hydrochloride (calcium-antagonist) was injected into the tail vein of each of the experimental rats 12 h and 23 h respectively after left anterior descending (LAD) occlusion. The same volume of saline was administered into the sham-operated group and MI model group. The ischemic size, ST elevation, serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), aspartate transaminase (AST), superoxide dismutase (SOD), malondialdehyde (MDA), and levels of SOD, MDA in myocardial tissue were measured in the rats at 24 h after LAD occlusion.

RESULTThe ischemic risk area ratio was 34.52 +/- 8.69% in the MI control group. Treatment of VAP at doses of 60 and 120 mg x kg(-1) resulted in reductions in the infarct size of (21.67 +/- 5.19)% and (19.56 +/- 9.15)% (P < 0.05), respectively. Treatment with VAP at doses of 30, 60 and 120 mg x kg(-1) significantly decreased ST elevation (0.28 +/- 0.03, 0.21 +/- 0.03, 0.16 +/- 0.02, 0.15 +/- 0.02) mV (all P < 0.01), compared with the MI control rats (0.41 +/- 0.05) mV. VAP also significantly decreased levels of CK, LDH, AST, MDA in serum and myocardial tissue, increase SOD activity in serum and myocardial tissue in MI rats.

CONCLUSIONVAP exerts significant cardioprotective effects against acute ischemic myocardial injury in rats, likely through its antioxidant and anti-lipid peroxidation properties.