To study the effect of a cholinergic muscarinic blockade on the gastric emptying rate during insulin-induced hypoglycemia in healthy subjects.
In eight healthy subjects, the rate of gastric emptying of an isotope-labeled meal was assessed by a scintigraphic technique during normoglycemia and hypoglycemia with simultaneous infusion of either atropine or saline. Blood glucose concentrations were controlled by an insulin-glucose clamp.
The median time for emptying 50% of the liquid phase from the stomach (T50) was 24.9 min (range 13.9−120.0) during normoglycemia compared with 8.1 min (range 3.6−16.5) during hypoglycemia without atropine infusion (P = 0.0005). The T50 for the solid phase was 26.8 min (range 9.7−74.0) and 43.1 min (range 29−57.8), respectively (P = 0.007). During hypoglycemia with atropine infusion, T50 was 40.7 min (range 10.0−120.0) for the liquid phase and 111.4 min (range 38.9−120.0) for the solid phase, not statistically different from normoglycemic examinations.
Cholinergic muscarinic blockade with atropine inhibits the increase in gastric emptying during hypoglycemia. Vagal activity seems to be an important determinant of gastric emptying during hypoglycemia.
