Purification of two equine pepsinogens by use of high-performance liquid chromatography

Objectives-To purify and characterize pepsinogens in equine gastric mucosa. Sample Population-Stomachs collected from 2 healthy horses at necropsy. Procedure-After collection, stomachs were placed immediately in ice before storage at -48 C. After slow thawing, the mucosa was scraped off while the tissue was immersed in 0.1 M potassium phosphate (pH 7.4) at 4 C, then was homogenized. The filtered extract was subjected to anion-exchange chromatog raphy. Fractions that were found to contain pepsin or pepsinogen were furth er chromatographed. Individual fractions were tested for pepsinogen or peps in content by monitoring proteolytic activity at pH 2 and 3, respectively. Fractions from all columns were analyzed by sodium dodecyl sulfate-polyacry lamide gel electrophoresis to confirm molecular weight of pepsinogens and p epsin. Results-Two pepsinogens and at least 1 pepsin were purified from equine gas tric mucosa. Conclusions-On the basis of molecular mass, equine gastric mucosa contains 2 pepsinogens. Clinical Relevance-Results of this study will enable future development of an ELISA or radioimmunoassay for use in the diagnosis of equine gastric ulc eration.