Search

This study examined the function in vitro of aganglionic colon musculature in mice with hereditary aganglionosis--a strain of animals used as a model of Hirschsprung's disease. Double sucrose gap recordings from the muscle strips of both normal and aganglionic colon showed bursts of spike potentials with muscle contraction. Intracellular recordings of the membrane potentials of the circular muscle cells of normal, aganglionic and oligo-ganglionic colon had no statistical difference. Microelectrode recordings from the circular muscle cells of normal siblings, in the presence of nifedipine, irregular ongoing fluctuations in membrane potential, which were abolished by tetrodotoxin and reduced by d-tubocurarine or apamin. The fluctuations were less effected by atropine. These observations suggest that there is ongoing inhibitory neural activity to the circular smooth muscle of normal colon. These ongoing fluctuations were not recorded from the cells of aganglionic and oligo-ganglionic colon of affected animals. Although transmural stimulation of the intrinsic nerves produced cholinergic excitatory and inhibitory junction potentials in normal colon, no junction potentials were evoked by transmural stimulation in aganglionic colon. It was concluded that the ongoing tonic inhibitory activity may contribute to the compliance of the normal mouse colon and lack of the compliance may affect functional intestinal obstruction of the aganglionic colon in Hirschsprung's disease.

A simultaneous manometric monitoring of the common bile duct (CBD) and the duodenum were performed 2 weeks after choledocholithotomy on 15 patients whose common bile ducts were explored without sphincteroplasty and 30 patients with sphincteroplasty. These manometric studies were carried out by open-tip catheters intubated into the CBD and duodenum through the T-tube at the operation. In patients without sphincteroplasty, no effects of the duodenal pressure on a CBD pressure profile were recognized, while a synchronized pressure profile of the CBD and the duodenum was obtained in patients with sphincteroplasty. By stimulation with morphine (Morphine sulfate; 0.17 mg/Kg iv bolus), waxing and waning of the pressured in the CBD without sphincteroplasty were observed with 20 cmH2O in maximum at about 13 minutes after injection. However, in the CBD with sphincteroplasty, scale-over increase of the pressure curve was seen immediately after duodenal contraction caused by morphine stimulation. A direct infusion of 5 ml of 0.1 N hydrochloride to the duodenum causes hyperperistalsis of the duodenum, which made a synchronized pressure profile in the CBD with sphincteroplasty but made no remarkable change in a pressure profile of the CBD without sphincteroplasty. These findings conclude that the sphincter of Oddi plays an important role as a "pressure barrier" between the CBD and the duodenum, and that with the destruction of this sphincter by sphincteroplasty, a pressure profile of the CBD becomes close to that of the duodenum. This simultaneous manometric study of the CBD and the duodenum might be one of most valuable methods for evaluation of completeness of the sphincteroplasty.

Daily profile of colonic motor activity was observed in 10 conscious dogs by means of extraluminal force transducers. Each dog was implanted with a set of seven strain, gauges, one on the terminal ileum and the remaining six on the colon equidistantly. The colonic motor activity was basically composed of migrating and non-migrating motor complexes at all six recording sites. Each motor complex was characterized by a tonic contraction superimposed by rhythmic bursts of phasic contractions. During fasted period these motor complexes recurred at a mean interval of 36 min, and a mean duration was 7 to 12 min. Those motor complexes which migrated over at least three recording sites were defined as "migrating", 72% of those observed at the most proximal sites (n = 2680) were migrating, and the remaining 28% were non-migrating. Of those migrating motor complexes 90.4% migrated caudad (iso-peristalsis), while only 9.4% migrated orad (antiperistalsis). During postprandial period the colonic motor complexes at all recording sites uniformly increased their frequency with shorter intervals. Different from the small intestine, the contractile patterns were essentially the same as those of fasted period. The postprandial acceleration of the colonic motor complexes seems to be compatible with gastrocolic response.

Intraluminal manometric and cine-cholangiomanometric studies were carried out on the movement of the sphincter of Oddi at the time of excretion of bile into the duodenum in 12 patients after cholecystectomy for gallstone. Two phases were observed in the sphincteric movement; the resting phase without any contraction and active phase with vigorous contraction. On stimulation with CCK-PZ 0.5 u/kg (bolus injection) in a active phase, a prompt transition from the active phase to the resting phase was observed in 4 to 8 minutes. On cine-cholangiomanometric study, the contrast medium injected into the common bile duct did not flow into the duodenum at the resting phase, but in the active phase. In the active phase, the excretion of the contrast medium was observed at the end of each contraction of the sphincter of Oddi. These observations have led a conclusion that bile excretion occurs in the active phase of the sphincter of Oddi in the cholecystectomized patients.