title: Rat trypsin: purification, radioimmunoassay and age-related serum levels in normal and spontaneously diabetic BB Wistar rats.
abstract: A convenient procedure is described for the purification of rat trypsin. Tissue was homogenized and extracted at pH 4 and the soluble fraction purified by a two-step affinity chromatography. After polyacrylamide gel electrophoresis at pH 8.8, the purified enzyme was resolved into 1 major and 2 minor bands all of which possessed trypsin-like enzyme activity. Antibodies to rat trypsin were raised in rabbits and utilized in establishing a sensitive radioimmunoassay procedure for the enzyme. The assay was adapted to study the levels of the enzyme in the circulation of normal Wistar and spontaneously diabetic Bio Breeding Wistar rats before onset of insulin-dependent diabetes mellitus in a longitudinal fashion. In the normal rat, serum levels of immunoreactive trypsin were higher in younger animals and showed a decline after weaning. This pattern was also seen in the Bio Breeding Wistar rats. In about half the number of Bio Breeding Wistar rats, serum immunoreactive trypsin levels were much higher than in normal rats. These results may imply that in some Bio Breeding Wistar rats the disease may be associated with inflammatory lesions of the exocrine pancreas.
mesh_terms: D000367:Age Factors; D000818:Animals; D002846:Chromatography, Affinity; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000201:enzymology*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D014357:Trypsin / Q000032:analysis / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D014357:Trypsin