AimTo investigate the biological distribution of 99mTc-anti-cardiac troponin T monoclonal antibody (99mTc-AcTnTMA) in the rats with acute myocardial damage.MethodsPrepared 99mTc-AcTnTMA and built the rat model of acute cardiac muscle damage.Then 60 rats were randomized into the experimental group, the control group and the blank group.There are twenty rats in one group.In the experimental group, 20 rats with acute myocardial damage were injected with 0.3 mCi 99mTc-AcTnTMA and were killed at 2, 4, 8 and 12 h after injection respectively (5 rats).Blood, liver, spleen, kidney, muscle, colon, lung and heart of each rat were taken and the injected dosage (ID%/g) and the ratio of ID%/g for heart-to-lung ratio (HLR) was calculated.In the control group and the blank group, 20 rats with acute myocardial damage were injected with 0.3 mCi 99mTc-N-IgG and 99mTc-AcTnTMA respectively and were killed and followed subsequent procedure in the same way as the experimental group. ResultsThe value of ID%/g and HLR in the experimental group were significantly higher than the other groups, which hinted that acute injury myocardium could uptake specifically the 99mTc-AcTnTMA and the specific uptake was observed with its peak 4 h after injection.Conclusion99mTc-AcTnTMA could be a useful tracer of myocardial imaging to diagnose acute myocardial damage.