日本薬理学雑誌
Online ISSN : 1347-8397
Print ISSN : 0015-5691
ISSN-L : 0015-5691
102 巻 , 4 号
選択された号の論文の4件中1~4を表示しています
  • 千葉 茂俊, 古川 安之
    1993 年 102 巻 4 号 p. 257-270
    発行日: 1993年
    公開日: 2007/02/06
    ジャーナル フリー
    The SA nodal pacemaker activity is regulated dominantly by autonomic nervous elements, i.e., sympathetic and parasympathetic nervous factors. In addition, circulatory bioactive substances and physicochemical factors also modify changes in sinus rate. Exogenously applied substances exert their actions on sinus rate directly and/or indirectly. The mechanisms of bradycardia and tachycardia induced by electrical nerve stimulation or exogenous substances are reviewed mostly by describing the results from experiments in isolated canine SA node preparations which were perfused with blood. In this review, newly developed bradycardic agents are introduced in addition to descriptions of numerous active substances developed in the past.
  • 矢野 敏之, 西 勝英
    1993 年 102 巻 4 号 p. 271-277
    発行日: 1993年
    公開日: 2007/02/06
    ジャーナル フリー
    Ion-selective electrodes have been used for many years to analyze ion activities in electrolyte solutions. In recent years, these electrodes have been miniaturized and applied for measurements in the cell interior. This article describes basic principles for both the fabrication and the intracellular application of ion-selective microelectrodes, particularly focusing on double barreled liquid ion-exchanger microelectrodes. The use of ion-selective microelectrodes allows continuous and real-time measurements of intracellular ion activities of a single cell in both multicellular and isolated cell preparations under various conditions, such as changes in ion composition of the extracellular bathing fluid and exposure to certain drugs. With double-barreled ion-selective microelectrodes, the transmembrane potential and intracellular ion activities can be measured simultaneously in the same cell. Although there are still some problems or limitations to the intracellular application of ion-selective electrodes, this technique is useful for determining the actual movement of intracellular ions, and thereby to elucidate cellular mechanisms of membrane transport and other physiological functions.
  • 川名 信, 木村 永一, 宮本 篤, 大鹿 英世, 並木 昭義
    1993 年 102 巻 4 号 p. 279-286
    発行日: 1993年
    公開日: 2007/02/06
    ジャーナル フリー
    We used a Fotonic Sensor™, a fiber optic displacement measurement instrument, to measure the chronotropy and the contractility of cultured neonatal rat cardiac myocytes. The principle of the measurement is to detect changes in the distance between the probe and myocytes vertically extruded by the contraction. A fiber optic probe consists of adjacent pairs of light-transmitting and light-receiving fibers. The ratio of reflected light to transmitted light changes proportionally to the distance between the probe and an object at a certain range shown in a calibration curve. The analogue output from the sensor was transferred to a personal computer through an analogue/digital converter and analyzed. The sensor was able to detect the rate of myocyte beating, i.e., chronotropy, with a high correlation to the frequency of electrically stimulated beating and agreed well with the beating rate counted visually under a microscope. The contractility was evaluated by the maximum contraction velocity (Vm) by the first derivatives of the contraction curves obtained by the sensor. Norepinephrine (NE) and isoproterenol (ISO) increased the contractility in cultured myocytes in a dose-dependent fashion. In the preparation of rat ventricular papillary muscle, NE- and ISO-induced increase in the Vm in the radial direction significantly correlated with the increase in tension measured with a force-displacement transducer. These results indicate that the Fotonic Sensor™ is an appropriate instrument for evaluating the chronotropy and the contractility of cultured myocytes.
  • 小田島 潤一, 増田 義勝, 村井 繁夫, 斉藤 弘子, 伊藤 真紀, 伊藤 忠信
    1993 年 102 巻 4 号 p. 287-294
    発行日: 1993年
    公開日: 2007/02/06
    ジャーナル フリー
    プラットホーム(P)と,そこから放射状に延びたアームおよびその先端にギロチンドア(G)を介して設けられたホームケージ(H)からなる装置において,Hには餌が,Pには水が置かれた.ddY系雄性マウス3群をそれぞれ4アーム,6アーム及び8アームの迷路装置の中で1日6時間飼育した.この際,Hに通じるアームは一つだけとし,それをランダムに変え,残りのアームの先端はGで行き止まりとした.この飼育後,他のケージに移し,翌日の試行まで絶食した.1試行は,全てのGが遮断された装置のPに置かれたマウスが全アームを選択し終えるまでとし,最後に選択したアームのGを開いてホームケージ内への進入を許した.試行時に未選択のアームに入ることを正選択,既選択のアームに入ることを誤選択(エラー)とし,課題の遂行は最初のエラーが生じるまでの正選択数(初期正選択数)で評価した.4アーム迷路で3.8以上,6アーム迷路で5以上,8アーム迷路で7以上の平均初期正選択数が3日連続したとき課題を習得したと見做し,これらのマウスを用いてスコポラミン(SCP:0.2mg/kgと0.4mg/kg,i.p.)および遅延時間(1分,2分,4分)の影響について検討した.飼育開始後,4アーム迷路では5日目の試行で,6アーム迷路では4日目の試行で,8アーム迷路では6日目の試行で習得基準に達し,以後そのレベルが持続された.SCP0.4mg/kgは,8アーム迷路において初期正選択数を減らし,4アーム迷路,6アーム迷路,8アーム迷路においてエラー数を増やした.遅延時間の挿入は6アーム迷路,8アーム迷路の初期正選択数を減らしたが,遅延時間の長さに依存した変化は認められなかった.以上の結果は,本装置がマウスに速やかに迷路課題を習得させ,また作業記憶におよぼす薬物効果の検討に有用であることを示唆した.
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