| Abstract: | Glucagon, somatostatin and insulin secretions were evaluated in a new type of perfusion preparation: the naturally A and D cell rich splenic bulb of duck pancreas. Stable basal levels were observed with 11 mM glucose, corresponding to normoglycaemia, and all secretions were stimulated by 1 mM 3-isobutyl-1-methyl-xanthine and by 10 mM arginine, demonstrating the technique's validity. In the absence of aminoacids in the perfusion medium, A cell blindness to glucose was corrected by physiological levels of insulin (2 ng/ml); insulinodependency of A cells, and unresponsiveness of D cells to glucose, probably not ruled by insulin, were observed. However, in the presence of aminoacids, glucagon was inhibited and somatostatin secretion stimulated by glucose (33 mM), independently of insulin (2 ng/ml). Aminoacids greatly influenced pancreatic hormone release. |
