125I-glucagon-degrading activity in acid-saline extracts of rat salivary gland.
The antibody-binding ability of the glucagon-like substance in rat submaxillary gland acid saline extract was examined by affinity chromatography, and the biological activity studied using the isolated liver perfusion method. We found that the glucagon-like substances in acid saline extract could not be bound to anti-glucagon antibody and that the gel-filtration peak on ultrogel AcA 54 could increase neither glucose nor cyclic AMP output from isolated perfused rat liver. Furthermore, the radioactivity peak of 125I-glucagon on Bio Gel P-6 column chromatography moved from its original position and eluted in later fractions after incubation with an acid saline extract of the submaxillary gland. In consequence, there was 125I-glucagon degrading activity in the submaxillary gland, but no glucagon-related peptide. Therefore, it is suggested that the glucagon-like substance, which has been reported in acid saline extract of the rat salivary gland, may be an artifact due to tracer degrading activity.
D000818:Animals; D002850:Chromatography, Gel; D005934:Glucagon / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007457:Iodine Radioisotopes; D008099:Liver / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D013363:Submandibular Gland / Q000032:analysis / Q000378:metabolism*; D014020:Tissue Extracts / Q000378:metabolism*; D014357:Trypsin
D007457:Iodine Radioisotopes; D010446:Peptide Fragments; D014020:Tissue Extracts; C029482:iodoglucagon; D005934:Glucagon; D014357:Trypsin