Metabolic comparison of radiolabeled aniline- and phenol-phthaleins with 131I

The metabolic comparison of aniline- and phenol-phthaleins radiolabeled with 131I (131I-APH and 131I-PPH, respectively) has been investigated in this study. To compare the metabolic behavior of these phthaleins and their glucuronide conjugates radiolabeled with 131I, scintigraphic and biodistributional techniques were applied using male Albino rabbits. The results obtained have shown that these compounds were successfully radioiodinated with a radioiodination yield of about 100%. Maximum uptakes of 131I-APH and 131I-PPH, which were metabolized as N- and O-glucuronides, were observed within 2 h in the bladder and in the small intestine, respectively. In the case of verification of considerably up taking of these compounds also by tumors developed in the small intestine and in the bladder tissues, these results can be expected to be encouraging to test these compounds, which will be radiolabeled with other radioiodines such as 125I, 123I and 124I as imaging and therapeutic agents in nuclear medical applications.