Synthesis of biologically active porcine secretin and [ITyr10] porcine secretin.

Porcine secretin, Tyr10] secretin, and Tyr13] secretin were synthesized by solid phase methodology and purified by stepwise gradient elution from a short reversed-phase column with ethanol and acetic acid as organic modifiers. Tyr10] secretin and Tyr13] secretin were iodinated by the chloramine-T method and nonmono-, and di-iodinated products separated and isolated by reversed-phase HPLC. Batch incubation analysis is isolated mouse pancreatic islets revealed that secretin and the Tyr10] analogue were indistinguishable in their effect on the glucose-induced insulin release and cAMP accumulation. Tyr13] secretin in contrast was significantly less potent in its effect on the glucose-induced insulin release.