Isolation and chemical characterization of somatostatin-28 from rat hypothalamus.

A peptide with somatostatin-like immuno- and bioactivity has been isolated from an aqueous extract of 96 800 rat hypothalamic by means of immunoaffinity chromatography, gel filtration and reverse-phase high-performance liquid chromatography (HPLC). Chemical characterization by amino acid analysis, tryptic peptide mapping and retention behavior in two HPLC system showed that the peptide was indistinguishable from somatostatin-28 previously characterized from several species. This evidence suggests that rat hypothalamic somatostatin-28 is identical in structure to porcine and ovine somatostatin-28.