The specific long spike burst pattern indicates the presence of regional variability in the ovine gallbladder motor function

Abstract

AbstractThe myoelectrical activity of ovine gallbladder is incompletely recognized. Accordingly, each of five rams was fitted with six small intestinal and three gallbladder electrodes. The strain gauge force transducer was also mounted near the gallbladder fundic electrode. In two series of chronic experiments the electromyographical and mechanical recordings were conducted during 5–7 h in fasted or non-fasted animals, with or without feeding. The occurrence of the slow waves in the small bowel was common, unlike those in the gallbladder. In the small bowel myoelectrical records both the migrating motility complex and minute rhythm pattern were observed regularly. In the gallbladder, both the migrating motility complex-like activity and the minute rhythm were also denoted in the same time as in the small bowel. In gallbladder infundibulum, and often also in the gallbladder corpus, the specific pattern, called the long spike burst pattern (LSBP) was observed. It comprised usually one or two parts of prolonged duration. The first part resembled the classical (short lasting) spike burst in the small bowel and its amplitude was lower than that of the second part. The spike burst frequency of the second part of the pattern was 2–3 times lower than that of the first part. During phase 1 – and phase 2a-like activity, the frequency of the gallbladder LSBP was reduced in fasted rams. The LSBP amplitude was relatively high and not further enhanced after feeding. In fasted rams, the duration of specific pattern, observed in gallbladder infundibulum, was longer than that in non-fasted animals and its amplitude was low. Similar events were recorded in the gallbladder corpus, but the LSBP was shorter and not regular. In the gallbladder fundus, mostly irregular short spike bursts were recorded. It is concluded that in sheep, specific types of the long-lasting groups of spikes occur in the upper gallbladder areas forming the specific pattern that indicates the presence of the regional variability of the gallbladder motor activity. The character of LSBP depends mostly on feeding conditions.