Studies on secretin. III. Purification of porcine secretin by high performance liquid chromatography and comparison of the product with synthetic secretin.

Natural porcine secretin was purified by high performance liquid chromatography (HPLC) in order to compare it with synthetic secretin. As a starting material we used partially purified secretin obtained by extraction from porcine duodenum followed by purification by ion-exchange chromatography and gel filtration. Preparative HPLC was performed on a reverse-phase column with a volatile eluent. The biological activity of the purified secretin was 5450 c.u./mg in the anesthetized rat, which is higher than those of other natural secretins reported so far (4000 c.u./mg), and was reasonably close to that of our synthetic secretin (5750 c.u./mg). The natural and synthetic secretins were compared by several physicochemical methods.