The dynamic gastric pressure response to expansion by direct intragastric air insufflation, 30-50 ml/s, was studied in healthy volunteers, non-operated ulcer disease patients, and in patients operated upon with antrectomy, antrectomy and vagotomy, or proximal selective vagotomy. Non-operated individuals accepted gastric expansion without considerable increase of pressure. Antrectomized patients showed a higher basal pressure and a moderate increase of pressure during expansion. Vagotomized patients, including the ones operated upon with proximal selective vagotomy, demonstrated a marked increase of pressure during expansion. The results indicate that vagal denervation of the corpus-fundus part of the stomach is followed by an impairment of gastric resrvoir function.