Digestion and Absorption of Radioactive Elastins in Rats

Abstract

Summary

The digestion and absorption of elastin was studied in rats by feeding intact or elastase-predigested elastin labeled with ¹⁴C or ³H. Radioactive elastins (59.3-71.5%) remained in feces whether feeding intact or predigested elastins. Of the absorbed products, 3.2-3.5% and 24.8-27.8% appeared in urine for [¹⁴C]- and [³H]elastin, respectively. However, desmosine-containing degrative products were not found in the urine. The absorption of [³H]desmosine was also studied following oral and intraperitoneal administration. Given orally, ³H appeared predominately in the feces, but when injected intra-peritoneally, ³H was mostly in the urine. Therefore, even if elastin were completely digested, desmosine would not be absorbed.