Abstract: 99Tcm LABELING AND ANIMAL EXPERIME NTS OF CACPPA Wu Chunying\ Ji Shuren\ Fang Ping\ Zhou Xiang\ Chen Zhengping \ He Yongjun(State Key Laboratory of Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063)Abstract\ 99TcmCACPPA is prepared by the reduct ion of stannous chloride with Na99TcmO－4 in aqueous soluti on a t pH8.5~9.5,the labeling yield and radiochemical purity are over 90% determined by TLC and HPLC. Biodistribution of 99TcmCACPPA in mice demonstra tes that the highest myocardial uptake of 99TcmCACPPA is 18.17±2. 67% ID/g. When blood disappearance of 99TcmCACPPA is analyzed with a biexponential model, an initial half time of 1.11 min and a late half tim e of 20.08 min are obtained. 99TcmCACPPA exhibite high binding to HSA in vitro and in vivo, partition coefficients are 10.98 and 11.45 at pH7.00 a nd pH7.40 respectively. The study of metabolism intervention showes that myocard ial uptake of 99TcmCACPPA in the group of glucoseinsulin is high er than that of normal, which has significant difference after ttest.Keywords\ p（N，N′dicarboxymethyl)aminomethyl ca r boxyaminophenylpentadecanoic acid (CACPPA)\ 99TcmCACPPA\ anima l experiment