The isolated in situ perfused rat pancreas was used to study glucose and catecholamine control of glucagon secretion, and to investigate the possible role of endogenous cyclic AMP as a mediator of this secretory process. When perfusate glucose was acutely dropped from 100 to 25 mg/100 ml, glucagon was released in a biphasic pattern with an early spike and a later plateau-like response. 300 mg/100 ml glucose suppressed glucagon secretion to near the detection limit of the radioimmunoassay (15 pg/ml). When perfusate glucose was dropped from 300 to 25 mg/100 ml, a delayed, relatively small peak occurred suggesting persisting alpha cell suppression by prior high glucose exposure. 2-Deoxy d-glucose stimulated glucagon secretion and inhibited insulin secretion.
Gordon C. Weir, Stephen D. Knowlton, Donald B. Martin