Plasma Immunoreactive Insulin (IRI) and Immunoreactive Glucagon (IRG) After Evisceration with and Without a Functional Liver

Abstract

Fed male Wistar rats were eviscerated by two procedures. The first group of eviscerated rats were left with a nonfunctional liver in situ while the second group were eviscerated by a newer technic, developed in this laboratory, that preserves liver function.7 The animals were maintained on a regimen of saline and antibiotic treatment, and abdominal aortic blood was drawn at intervals up to seventy-two hours postoperatively from animals with a functional liver and up to six hours postoperatively in those with nonfunctional liver status. Blood concentrations of glucose, immunoreactive insulin, and immunoreactive glucagon were measured. Our results indicate that even with a functional liver, totally pancreatectomized eviscerated rats maintained normal amounts of plasma IRI and IRG for more than twenty-four hours. IRI and IRG were measurable even at forty-eight hours postoperatively. At the same time, these animals developed abnormally high blood glucose levels, which were sustained despite the presence of “normal” IRI in plasma. It had been suggested that the presence of measurable IRI and IRG in the classically prepared eviscerated animal was due to a deficit liver destruction of these substances. To the contrary, our data suggest that even with a functional liver, the eviscerated preparation maintains a circulating level of insulin and glucagon-like materials forty-eight hours after the known sources of such substances are removed. The physiologic meaning of immunoassay results following pancreatectomy are thus difficult to interpret.