Role of vagal innervation on intragastric distribution and emptying of liquid and semisolid meals in conscious pigs

The role of vagal innervation on emptying patterns and intragastric distrib utions of liquid and semisolid meals is still controversial. We aimed to re cord these features after dorsal, ventral and truncal vagotomies, using ext ernal gamma scintigraphy in conscious pigs in which the dorsal vagus specif ically innervates the proximal stomach. Imaging of the stomach was performe d for all experimental situations and before surgery using Tc-99m-labelled glucose and porridge meals. Emptying of liquids was faster after dorsal vag otomy, whereas it was unchanged after ventral and truncal vagotomies (T-1/2 =57 +/- 8.5, 31 +/- 14.4, 54 +/- 9.1 and 42 +/- 14.9 min for intact, dorsal , ventral and truncal vagotomies, respectively). On the other hand, truncal vagotomy significantly reduced the emptying rate of semisolids whereas dor sal and ventral vagotomies had no significant effect (T-1/2=96 +/- 7.2, 113 +/- 8.1, 75 +/- 9.9 and 260 +/- 56.6 min for intact, dorsal, ventral and t runcal vagotomies). Morphological analysis of the gastric shape confirmed a n overdistended proximal stomach after truncal vagotomy only. For semisolid s, proximal stomach emptying followed the same emptying pattern as the enti re stomach, irrespective of the surgical procedure. We concluded that the p roximal stomach is the main control for the emptying of liquids and semisol ids. The vagal control of overall gastric emptying for semisolids is probab ly identical to that modulating the intragastric distribution of the meal.