Degraded and Undegraded Insulin in the Bile of Rabbits After Intravenous Administration of Tracer Amounts of Labeled Insulin

Summary

During the first hour after the intravenous administration of tracer concentrations of labeled insulin into the portal vein as well as into the abdominal vena cava, significant amounts of radioactivity appear in the bile of rabbits. About 43% of this radioactivity represents undegraded insulin. The total recovered radioactivity drops after the first hour, remaining constant thereafter for at least 5 hours. During this time the degradation of the hormone is intensified and no more than 15-18% of the recovered radioactivity represents immunologically active insulin.