Japanese Journal of Smooth Muscle Research
Online ISSN : 1884-8788
Print ISSN : 0374-3527
ISSN-L : 0374-3527
Volume 16, Issue 4
Displaying 1-5 of 5 articles from this issue
  • Hiroshi TAKAYAMA, Tsutomu SOHMA, Satoru SUNANO
    1980 Volume 16 Issue 4 Pages 271-283
    Published: December 28, 1980
    Released on J-STAGE: July 21, 2010
    JOURNAL FREE ACCESS
    1. When the blood from rabbit or from human was subjected to hemolysis in the test tubes, K-concentration of serum was elevated to about 40mEq/l. According to these result, the effects of K ion of the concentration up to 30mM on the contractile response were studied.
    2. When the K-concentration was elevated to 10mM or 20mM, a transient relaxation was observed. The relaxation, however, was transient and reversed into contraction. No relaxation was observed when K-concentration was elevated gradually.
    3. Basilar artery showed higher sensitivity than carotid artery to the elevation of extracellular K-concentration and showed a contractile response to lower K-concentration. Sensitivity to noradrenaline, on the other hand, was lower than that of carotid artery.
    4. The contraction by K was stronger in the preparation which showed spontaeous contractions. The contractile response to K was abolished by Ca removal, verapamil (10-5M), La (10-4M) or Mn (2mM).
    5. Phentramine (2×10-5M) depressed the contractile response. TTX (5×10-7g/ml), atropine (10-6M) or methysergide (5×10-5 M) showed no effect on the contraction by K.
    It was suggested that, although the contractile response to elevated K may be due, in part, to the released cathecholamine, it was caused mainly by the direct action of K, especially by its depolarizing action.
    Since the action was stronger in the preparation which showed spontaneous contraction, the spike activity, in addition to the depolarization, might have important role for this contraction.
    The contraction may be brought about by influxed Ca caused by the depolarization and/or action potential (Ca spike). It was also suggested that this effect can be one of the cause of the spasm of cerebral blood vessels.
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  • Shin'ichi AMANO, Makoto HONZUMI, Masaki FUJIOKA, Hiroshi SUZUKI
    1980 Volume 16 Issue 4 Pages 285-295
    Published: December 28, 1980
    Released on J-STAGE: July 21, 2010
    JOURNAL FREE ACCESS
    Manometric pressure profile of the lower esophageal sphincter (LES) was measured with perfused 3-lumen tube (Sherwood Type I, Fr.10) at 3 different directions at the same level in dogs.
    1. Measurement in 8 mongrel dogs disclosed that LES pressure was significantly high at right anterior (2 o'clock) and left anterior (10 o'clock) directions compared with pressure at dorsal direction (6 o'clock). There was no statistically significant difference of LES length 3 different directions.
    2. LES pressures and lengths were signfiicantly increased and difference of LES pressures among 3 different directions was amplified by intravenous administration of 4μg/kg/hr of Tetragastrin.
    3. LES pressures and lengths were not affected by intravenous administration of 0.5mg/kg/hr of Atropine sulfate.
    4. LES pressures were preserved, but LES lengths were shortened by division of the phrenicoesophageal ligament. Difference of LES pressures among 3 different directions disappeared of ter this procedure. Division of the phrenico-esophageal ligament produced the “second” high pressure zone at directions of 2 and 10 o'clock.
    The present studies suggest that difference of LES pressures, or lengths in different directions is a product of anatomical structures of the hiatal muscle, and not of LES itself.
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  • Takashi KITA
    1980 Volume 16 Issue 4 Pages 297-305
    Published: December 28, 1980
    Released on J-STAGE: July 21, 2010
    JOURNAL FREE ACCESS
    To study the movement of dog colon, bipolor electrodes and strain gauges were attached to the four different portions, ascending, transverse, descending and sigmoid colons.
    Myoelectrical activities and mechanical activities were recorded simultaneously in the conscious state for one month.
    Slow waves were recorded more clearly in the proximal colon than in the distal colon.
    The frequencies of the slow waves were 5-6 cycles/min and were not altered by intravenous administration of motor stimulant agents. A spike activity complex was recorded more frequently in the distal colon than in the proximal colon. The spike activity complex usually appeared when contraction movement of the colon was active. The incidence of spike activity complex was mostly high in the descending colon. Contractile activity appeared once every minute with spike activity complex lasting for 10-30minutes.
    On a low residual meal, mechanical activity and spike activity complex propagated from ascending colon to rectum were observed more distinctly than on usual dog food.
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  • Takashi KITA
    1980 Volume 16 Issue 4 Pages 307-313
    Published: December 28, 1980
    Released on J-STAGE: July 04, 2011
    JOURNAL FREE ACCESS
    The electric activity of the colon was studied in unanaesthetized dogs equipped with 4 bipolor electrodes in the colon. Computer analysis of signals was made. Recorded electrical activities in the colon were mainly consisted of 2 rhythmic patterns. One was a low frequency rhythm of 3.3 to 6.6cycles/min and the other was a higher frequency rhythm of 9.2 to 13.4cycles/min. However, the frequency varied within the two rhythmic patterns in the same poritions of the colon.
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  • Motohide YAMASHITA
    1980 Volume 16 Issue 4 Pages 315-329
    Published: December 28, 1980
    Released on J-STAGE: July 21, 2010
    JOURNAL FREE ACCESS
    In dogs anesthetized by pentobarbital sodium, bipolar stimulating and recording electrodes were implanted on the gastric serosal surface and pacing effect of stimuli of rectangular current on the basic electric rhythm (BER) was examined.
    For judgment of pacing, the appearance of a compensatory pause after off-stimulation was a useful criterion. When BER was recorded at the oral side of stimulation, antiperistaltic one was added. Maximum driven frequency (MDF) was 6.0Δ0.6 (SD) cycles/min. The relation between stimulus interval (x) and BER interval (y) was represented by y=x in the stimuli below MDF. In the stimulus frequency until 2 times of MDF above MDF, it was replaced by y=2x. Phase lag between BERs of two separated points was increased as the stimulus frequency was increased up to MDF. This tendency was observed similarly within 2 times of MDF above MDF.
    Using a gastrointestinal fiberscope, electric stimulation was delivered from the gastric mucosal side, while BER was recorded from the serosal side in 5 dogs and was recorded with electrodes through the endoscope in 2 dogs. Pacing was possible, too.
    These results may indicate that pacing and recording of the BER using gastrointestinal fiberscope are applicable clinically.
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