The effects of glucose, glucagon and sulfonylureas on insulin release from chicken pancreatic pieces

Investigations of insulin release from the avian endocrine pancreas in vivo have indicated some anomalous, if not contradictory, responses to experimental manipulation when compared to similar studies conducted in mammals. In the present work insulin release from the chicken pancreas was studied in vitro in order to evaluate this process without the influence of compensatory homeostatic factors. These investigations were conducted by incubating small (20 5mg) pancreatic pieces from Single-Comb, White Leghorn hens in four successive 15-min experimental periods following a 30-min preincubation period. Release of immunoreactive insulin into the incubation medium was measured in response to various glucose concentrations, glucagon, sulfonylureas, and in the presence and absence of extracellular calcium. [...]