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    In vitro sensitivity of mouse esophagus to agonists in different pH medium values
    (W B Saunders Co-Elsevier Inc, 2007) Soyer, Tutku; Keskil, Zuhal Aktuna; Somuncu, Salih; Aydos, Tolga Reşat; Korkut, Oğuzhan; Kanmaz, Turan; Çakmak, Murat
    Aim: The aim of this study is to determine the in vitro sensitivity of mouse esophagus to contracting and relaxing agonists in different pH medium values. Materials and Methods: Forty-eight Swiss albino mice (30-40 g) of both sexes were anesthetized with tiopental sodium (30 mg/kg). After exsanguinations from abdominal artery, esophagi were removed and suspended under 0.6 g of resting tension in a tissue bath containing 10 mL of Krebs solution at 37 C. The experiments were performed in different pH mediums 7.4, 6.4, 4, and 2. Carbachol and acetylcholine were used as contractile agonists, and noradrenalin and isoproterenol to evaluate relaxation responses. Data concerning similar concentrations of contractile agonists obtained from different pH mediums were analyzed using Kruskal-Wallis nonparametric analysis of variance and post hoc Dunn test. Relaxation responses were compared with Student t test. A P value less than .05 was considered significant. The study was approved by Local Ethical Committee of Kmkkale University. Results: Carbachol and acetylcholine caused concentration-dependent contractility in pH 7.4, 6.4, and 4, but contractile responses were inhibited in pH 2. In carbachol and acetylcholine experiments, there was a significant decrease in contractile responses to all concentrations in conjunction with a decreased in pH value. Relaxation responses in pH 2 and 4 could not be obtained because precontraction of tissues was not possible. Noradrenalin and isoproterenol produced concentration-dependent relaxations in pH 7.4 and 6.4. Although noradrenalin responses showed no significant difference according to pH, isoproterenol caused better relaxations in pH 6.4 (between 10(-8) and 10(-6) mol/L) when compared to pH 7.4 studies. Conclusion: The mouse esophagus has impaired contractile responses to carbachol and acetylcholine in decreased pH values. Contraction responses did not occur in pH medium of 2. In contrast, esophagus segments showed better relaxations in lower pH values with isoproterenol. (c) 2007 Elsevier Inc. All rights reserved.
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    Pentylenetetrazol-induced seizures are not altered by pre- or post-drug exposure to a 50 Hz magnetic field
    (Taylor & Francis Ltd, 2007) Canseven, Ayşe G.; Keskil, Zuhal Aktuna; Keskil, Semih; Seyhan, Nesrin
    Purpose: To investigate whether pre- and post-drug magnetic field (MF) exposure of 50 Hz, 0.2 mT has any significant effect on pentylenetetrazol (PTZ)-induced seizures in mice. Material and methods: MF was generated by a pair of Helmholtz coils. Seizures were induced by PTZ injection intraperitoneally (i.p.) at a dose of 60 mg/kg. A total of 48 locally bred adult female mice 25 - 35 g in weight were used. Latency to seizure, total seizure duration, and mortality were recorded for each mouse. Results: Neither pre- nor post-drug exposure to a 50 Hz, 0.2 mT MF was found to have any effect on PTZ-induced epileptic seizures or mortality rates in mice. Conclusion: The present study failed to provide any support for a therapeutic potential of a 50 Hz, 0.2 mT MF for epilepsy.