Synthesis and biologic distribution of radioiodinated β-adrenergic antagonists

Article abstract of DOI:10.1021/jm00206a025

Iodinated analogues were prepared from propranolol, practolol, and acebutolol in 30-50% yields. Radioisotopic exchange between carrier-free Na ¹²⁵I and the molten iodinated β-adrenergic antagonist yielded the corresponding ¹²⁵I-labeled product. The biodistribution in rats, determined at 15 and 60 min postinjection, indicated that the radioiodinated analogues of the cardioselective drugs practolol and acebutolol localized to a greater degree in the liver and heart than the analogue of propranolol. Conversely,[¹²⁵I]iodopropranolol was concentrated to a greater extent in the lungs than [¹²⁵I]iodopractolol or [¹²⁵I]iodoacebutolol. Therefore, ¹²³I- or ¹³¹I-labeled cardioselective β-adrenergic antagonists may prove useful as radiodiagnostic agents for the external imaging of the myocardium.