Canine C-peptide for characterization of experimental diabetes in dogs.

Radioimmunoassay of canine C-peptide (CCP) was developed for the characterization of endogenous beta cell function in experimentally diabetic dogs. The animals were rendered diabetic by subtotal pancreatectomy and intrasurgical infusion of 2 mg kg-1 streptozotocin into the superior pancreaticoduodenal artery. After an average duration of diabetes of 5 months the animals showed zero peripheral venous fasting CCP levels with no response to feeding, OGTT/i.v. glucagon loading or i.v. glucose tolerance testing. The data on CCP levels were entirely coincident with simultaneously measured plasma IRI levels. In non-diabetic control animals there were clear-cut CCP increases after all stimuli. The experimental model provided an IDDM-type diabetes without toxic symptoms but with sufficient exocrine pancreatic function. The comparison showed that plasma IRI analyses would also allow a reliable characterization of insulinogenic functions in these animals.