Motor and electric activity of the duodenum

Abstract

Recordings of pressure and electric potentials from Biebl loops of the duodenum of trained dogs were used to quantitate and to determine relationships among basic electric rhythm (BER), irregular bursts of spike potentials, and motor action of the duodenum. After control periods, morphine was used to stimulate rhythmic motor activity. The omnipresence of a stable, longitudinally propagated BER was demonstrated, each phase of which was detected simultaneously by electrodes arranged radially in the wall of the gut. Spike potentials were recorded whenever contraction of the gut wall was detected. The spikes occurred during a limited segment of the BER. Their number and amplitude were directly related to the strength of the contractions. Under control conditions, duodenal contractions associated with the spike potentials produced type I waves in the pressure record. Neither the spike potentials nor the type I contractions were conducted more than a few centimeters. With morphine only the latter portion of the BER showed minor changes. Incidence of spike potentials and contractions was increased. Occasionally morphine induced motor spasms, accompanied by a prolonged series of spike-like potentials and disruption of the BER.