EFFECT OF ELECTRICAL-STIMULATION ON GASTRIC ELECTRICAL-ACTIVITY, MOTILITY AND EMPTYING

The aim was to measure the effect of gastric electrical stimulation on the frequency of canine antral pacesetter potentials (PPs), the stren gth of antral contractions, and the rate of gastric emptying while fas ting, after feeding and with pentagastrin stimulation. Four conscious dogs with a stimulating electrode placed 10 cm proximal to the pylorus and recording electrodes and strain gauges placed 7, 5 and 3 cm proxi mal to the pylorus underwent myoelectric and strain gauge recordings w hile fasting, after feeding (250 ml 5% dextrose labelled with polyethy lene glycol), and during pentagastrin infusion (0.5 mug kg-1 min-1) on four separate days. On each day, electrical stimulation was done usin g one of four stimulation frequencies (0, 6, 30 and 1200 stimuli per m inute [s.p.m.]). Stimulation at 6 and 30 s.p.m. increased the fasting and fed PP frequency, whereas 1200 s.p.m. stimulation did not. Feeding decreased the maximum driven frequency, and pentagastrin increased it . Neither the motility index nor the gastric emptying rate were consis tently changed by stimulation at any frequency. In conclusion, canine proximal antral stimulation at 6 and 30 s.p.m. sped PP frequency durin g fasting and after feeding, but stimulation over a wide range of freq uencies had little effect on gastric contractions and emptying.