Preparation of 188Re-Labetalol as a β1-Adrenoceptor for Use in Nuclear Medicine

Labetalol was labeled with 188Re. The reaction conditions (amounts of stannous chloride and substrate, pH, time) were optimized, and the radiochemical yield as high as 95 ± 0.4% was reached. Biodistribution in mice was studied. 188Re-Labetalol showed excellent initial heart uptake and good retention. The heart/liver ratios were 5.16, 2.70, and 2.15 at 30, 60, and 120 min post injection, respectively.