Abstract
1. The effect of phentolamine 5 mg i.v. on basal and pethidine-induced inhibition of gastric emptying of semisolid TC-99m labelled Chelex-100 resin/oatmeal was studied in ten healthy volunteers. 2. Each volunteer acted as his/her own control. 3. Basal gastric emptying remained unchanged after administration of phentolamine. 4. Administration of phentolamine reversed the pethidine-induced inhibition of gastric emptying.