Nihon Heikatsukin Gakkai zasshi最新文献

Responses of isolated muscle strips from the rat and the dog internal anal sphincter (IAS) to drugs and electrical field stimulation (EFS) were investigated in vitro for the purpose of clarifying a manner of neural control of IAS. Also, responses of muscle strips from IAS of the patients with Hirschsprung's disease were compared with those of muscle strips from human control IAS. Muscle strips from the dog and human IAS as normal control showed contractions to norepinephrine (NE), which were abolished in the presence of phentolamine and relaxations to isoproterenol. EFS (less than 1 msec) induced relaxations of the muscle strips. These responses to EFS were not affected by either one of phentolamine, propranolol and atropine but were inhibited by tetrodotoxin. Muscle strips from IAS in Hirschsprung's disease contracted to both NE and EFS, the responses of which were abolished in the presence of phentolamine. But no relaxation to EFS of muscle strips from IAS in Hirschsprung's disease was observed. These findings revealed that normal IAS is pharmacologically innervated by alpha-adrenergic excitatory nerve, beta-adrenergic inhibitory nerve and non-adrenergic, non-cholinergic inhibitory nerve and suggested that IAS in Hirschsprung's disease is also affected by alpha-adrenergic excitatory nerve but inhibitory neural control is absent.

Cutaneous recording of electrogastrography reflects gastric mechanical activity. Epigastric leads are superior in recording characteristics than meso-gastric leads, in fasting state, 3.0 cpm waves dominate EGG recording in fasting state. In this study, we analyzed the EGG recording characteristic after feeding in 10 normal subjects. Though the physical changes of gastric shape and volume after feeding, EGG recording was dominated by 3.0 cpm waves. Epigastric leads are still superior in recording characteristics, amplitude of EGG waves and read-abilities, than meso-gastric leads, after feeding. Amplitude of EGG waves increased after feeding when compared to fasting state, suggesting increased mechanical activity of the stomach. We conclude that epigastric leads are suitable in recording of EGG in fasting and in fed state in normal subjects. This position could be most standard recording leads for EGG in clinical settings.

Verapamil (10(-6) M) significantly reduced a development of the membrane depolarization and the contracture which were induced by Na removal. The fully developed depolarization, after exposure to Na-free solution, was reduced greatly by verapamil, excess Ca (15 mM) or sodium nitroprusside (10(-6) M), but some depolarization still remained. This remaining depolarization was completely blocked by readmission of 10 mM Na to Na-free solution containing verapamil, excess Ca or sodium nitroprusside. However, Mn (1.5 mM) did not block the depolarization due to Na removal and if Mn was present in Na-free solution, readmission of 15 mM Na to Na-free solution was not able to block the depolarization. On the other hand, the contracture due to Na removal was inhibited by addition of Mn (1.5 mM) or sodium nitroprusside (10(-6) M), but partially by addition of verapamil (10(-6) M) or excess Ca, to Na-free solution. These remaining contractures were also abolished by readmission of 10 mM Na to Na-free solution containing verapamil or excess Ca. Thus, these results suggest that the depolarization and the contracture due to Na removal are induced by increase in cytoplasmic Ca concentrations through (1): verapamil-sensitive Ca channel, (2): Na-Ca exchange system and (3): some mechanism which is inhibited by sodium nitroprusside.

The effect of AS-4370 given in single doses of 2.5, 5 and 10 mg on gastric emptying was investigated using 99mTc-DTPA in healthy volunteers in the placebocontrolled double-blind crossover design. There was no difference in percent activity throughout the period of measurement between AS-4370 2.5 mg and placebo. The percent activity decreased after administration of 5 and 10 mg of AS-4370 in comparison with placebo: the decrease was found during the period from 10 to 18 minutes after start of recording at 5 mg and from 8 to 18 minutes after start of recording at 10 mg. These results demonstrated that AS-4370 at these dose levels apparently accelerated gastric emptying. The analysis of the half emptying time by the crossover method showed that only the time effect was found at 2.5 mg, whereas the half emptying time was obviously shortened at 5 and 10 mg. There was no difference between 5 mg and 10 mg. There was no finding that might warrant a caution in terms of safety. In conclusion, AS-4370 did not affect gastric emptying at 2.5 mg but apparently accelerated gastric emptying at 5 and 10 mg in healthy volunteers.

LES pressure increase following diaphragmatic contraction as a pinch-cock action acts as one of the barrier mechanism for gastroesophageal reflux. In achalasia patients, incomplete LES relaxation following wet swallow is one of the characteristic manometric findings, along with loss of peristalsis. On the other hand, it has been reported that swallowing effort or esophageal distention have no effect on the increase of LES pressure induced by diaphragmatic contraction, which condition is similar to achalasia. Therefore, to evaluate that whether diaphragmatic contraction is involved in the cause of achalasia, we recorded diaphragmatic electromyography (DEMG) using bipolar electrodes in 12 achalasia patients and 4 normal subjects. The phasic DEMG amplitude was 80-90 microV in normal subjects and achalasia patients. LES pressure and DEMG amplitude increased during both straight leg raising (SLR) and abdominal distention (AD), both of the maneuver induce diaphragmatic contraction, in normal subjects and achalasia patients similarly. From the data obtained with this equipment, we conclude that diaphragmatic involvement is not likely as a pathogenesis of LES dysfunction in achalasia patients.

The present study investigates the ureteral action potential and histological changes of pelvi-ureteral system after injection of the formalin into the obstracted ureters or the renal pelvis. In the first experiment, formalin was injected into the obstructed ureters of 18 dogs for 30 minutes. In the second, formalin was injected into the obstracted renal pelvis of 13 dogs for 30 minutes using ureteral balloon catheters, and then renal pelvis were released from obstraction and catheters were removed. In these experiments, ureteral electromyogram were recorded and histological changes of pelvi-ureteral system were also observed microscopically. Results 1. After injection of formalin into the ureters, ureteral action potential disappeared and had not restored. Histologically, damage was observed in the ureteral smooth muscle as well as in the mucosa. 2. After injection of formalin into the renal pelvis, ureteral action potential disappeared in 46% of the ureters. In 54% of the ureters, action potential had not disappeared, however discharge interval became irregular. Histological changes of the renal pelvis was not related to the presence or absence of ureteral action potential. The results of the present study show that ureteral smooth muscle play part in the conduction of the ureteral excitation, and have an irregular autonomic discharge.

The spasmolytic action of bile salts on gallbladder smooth muscle could explain the alleged relief of biliary colic seen during bile acid therapy. The mechanisms of spasmolytic action of bile salts, ursodeoxycholate and deoxycholate were studied in the isolated gallbladder of guinea-pigs. The bile salts accelerated the 45Ca-efflux from the gallbladder with synchronous relaxation and inhibited the cellular 45Ca-uptake by the depolarized muscle preparation. Further, they sensitively inhibited CaCl2-induced contraction of the depolarized muscle. The tissue cyclic AMP content of the gallbladder was significantly elevated by the bile salts. Dibutyryl cyclic AMP mimicked the effects of bile salts on the Ca-efflux and the muscle relaxation, but showed no effect on the cellular Ca-uptake. From these results, it is suggested that the bile salts produce the relaxant action through accelerating Ca-efflux, which is probably coupled with the elevation of the cellular cyclic AMP level, and through suppressing the Ca-influx across the cell membrane.