Modulation of the slow potentials frequency of the stomach under the effect of the intrinsic nervous system.

Chronic and in situ experiments on dogs have been carried out involving stomach transection at the level of incisura angularis. The electrical acivity of the muscle wall of the two stomach segments was recorded by silver bipolar ball-shaped electrodes. Two electrodes for myogenic stimulation were implanted in the distal segment. Transection caused dissociation of the slow potentials rhythm in both stomach segments: slow potentials frequency in the distal segment is considerably reduced. Infusion of cholino- and adreno-mimetics in the artery supplying the distal segment causes increase of the frequency of the slow potentials in the distal segment to reach the frequency of the proximal segment. Bocking of the intrinsic nervous system eliminates these responses. On the background myogenic stimulation induces increased frequency of the rhythm in the distal segment. It is concluded that the intrinsic nervous system plays a role in maintaining slow potentials frequency in the stomach at a higher level than the level characteristic of this stomach segment.