Radioiodination of Cyano pindolol: An Ideal Candidate for the in Vitro Mapping of Cardiac p-Adrenergic Receptors

Cyano pindolol, a high affinity p-adrenergic receptor antagonist was labeled with radioiodine using different oxidizing agents such as lactoperoxidase and chloramine-To The effects of different reaction parameters such as temperature, reaction time, oxidizing agent concentration, ph, substrate concentration and the stability of the labeled product have been investigated. Chromatographic analysis of the reaction mixture by TLC using ethanol:ethylacetate (1: 1) and by HPLC using acetonitrile: 0.1 M ammonium carbonate (1:1) as eluent showed that the optimum radiochemical yield of the final product is 86% and the radiochemical purity is 99%. Also HPLC chromatographic analysis indicated that the undesired side products especially the chlorinated products in case of chloramine-Tis greater than that in case of lactoperoxidase. It's found that, in case of using lactoperoxidase method, minimum undesired side products were produced, therefore high radiochemical purity was produced.