Insulin and glucagon release from cultured neonatal pancreatic islets of lean and preobese Zucker rats.

Pancreatic islets were isolated from individual neonatal (2-5 days of age) lean and preobese Zucker rats to assess insulin and glucagon release were elicited with high glucose (22.2 mM) plus aminophylline (10 mM) and alanine (10 mM), respectively. The similar secretory hormone patterns, both at basal and stimulated conditions, of the islets from rats later identified as lean or obese, suggest that a primary islet defect does not cause the hyperinsulinemia.