TABLE 1

Recovery of radioactivity from the extraction residue of thoracic aorta treated with collagenase, elastase, and pronase after a single oral administration of ¹⁴C-YM758 to nonalbino rats

Total amount of radioactivity before treatment: 24,642 and 16,581 dpm/tissue (4 and 24 h). The pooled thoracic aorta samples (4 and 24 h) taken from nonalbino rats dosed with ¹⁴C-YM758 (3 mg/kg) were homogenized with a mixture of 2 mol/l hydrochloric acid and methanol (5:95, v/v) and centrifuged. The radioactivity from the precipitated residue was then recovered by sequential treatment with collagenase, elastase, and pronase, as described under Material and Methods. The values presented are the ratios (percentage) of radioactivity recovered after the samples were extracted with the organic solvent or enzyme treatment described above, to the radioactivity in the precipitated residue, which is prior to the extraction in each step (organic solvent, collagenase, elastase, and pronase treatment steps).