Radioiodinated esmolol as a highly selective radiotracer for myocardial perfusion imaging: In silico study and preclinical evaluation.

Challenges facing cardiovascular imaging necessitate innovation of better radiopharmaceuticals to augment or replace the existing ones. This research assesses the ability and competency of radioiodinated esmolol as a potential cardio selective imaging agent. Radioiodinated esmolol was synthesized with 97.3 ±â€¯0.3% radiochemical yield and with high stability up to 48 h at room temperature as well as in rat serum. Molecular modeling study was performed to confirm the binding of iodinated esmolol to ß1-adrenergic receptor. Its biodistribution studies in normal Swiss albino mice showed high heart uptake (38.5 ±â€¯0.11%ID/g at 5 min p.i.), heart/liver ratio nearly 3.85:1 and heart/lungs ratio was about 7:1 at 5 min p.i. The evidenced selectivity of the radioiodinated esmolol to ß1-adrenoceptor was confirmed by prior injection of cold esmolol. Gamma camera biodistribution pattern showed that radioiodinated esmolol accumulated selectively in heart.

Radioiodination and biological evaluation of nizatidine as a new highly selective radiotracer for peptic ulcer disorder detection.

Nizatidine has been labeled using [125 I] with chloramine-T as oxidizing agent. Factors such as the amount of oxidizing agent, amount of substrate, pH, reaction temperature, and reaction time have been systematically studied to optimize the iodination. Biodistribution studies indicate the suitability of radioiodinated nizatidine as a novel tracer to image stomach ulcer. Radioiodinated nizatidine may be considered a highly selective radiotracer for peptic ulcer imaging.