The effect of surgical anaesthesia on antral motility in the ferret

Gastric motility was recorded from ferrets chronically prepared with an antral strain gauge. In fasted animals, antral motility showed cycles of activity and quiescence typical of the migrating motor complex (MMC) with a period of 44.7 +/- 6.1 min (n = 4). Anaesthesia with pentobarbitone sodium (50 mg/kg) disrupted this interdigestive motor pattern which returned along with recovery from anaesthesia. The first cycle of antral motility occurred 119 +/- 23.9 min after the onset of anaesthesia and thereafter continued to cycle at the pre-anaesthetic interval. The recovery was unaffected by treatment with guanethidine (2 mg/kg) or naloxone (1.25 mg/kg) but all motility was prevented with atropine (100 micrograms/kg). Following chronic truncal vagotomy cycles of antral activity persisted during pentobarbitone anaesthesia. With prolonged anaesthesia with ethyl carbamate (1300 mg/kg) there was no return to antral cycling but instead continuous low amplitude regular contractions were present. The lack of MMC activity in acute experiments is thus a consequence of the anaesthesia and not the surgical interventions.