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Öğe Effect of whole gut irrigation solutions on gastrointestinal smooth muscle activity(W B Saunders Co-Elsevier Inc, 2009) Soyer, Tutku; Aydos, Tolga Reşat; Hancerlıoğulları, Oymen; Korkut, Oğuzhan; Aktuna, Zuhal; Çakmak, MuratBackground/Purpose: It has been suggested that whole gut irrigation (WGI), which is a preparation method for large bowel surgery or colonoscopy, increases gastrointestinal motility by creating a gastrocolic reflex. An experimental study was performed to evaluate the effect of different WGI solutions on gastrointestinal smooth muscle activity. Materials and Methods: Thirty Wistar albino rats weighing 200 to 250 g were enrolled in the study. After anesthetization with thiopental sodium (50 mg/kg), proximal ileum, terminal ileum, and colon segments were removed via median laparotomy to obtain a control group. Four different groups (n = 6) were designated as having WGI with saline solution (SS), lactated Ringer's solution (RL), polyethylene glycol (PEG), and dibasic sodium phosphate (DNP). Bowel cleaning was performed by infusing solutions at a rate of 2 mL/min via gastric tube, until the stool was cleared. After completing the bowel cleaning, 2 cm of tissues were removed and suspended in Tyrode solution in an isolated organ bath with a resting tension of I g, to obtain carbachol and potassium chloride (KCl) responses. Results: The mean bowel cleaning times were 87.5 +/- 9.35, 81.6 +/- 9.83, 86.6 +/- 11.6, and 85.0 +/- 0.0 minutes in SS, RL, PEG, and DNP groups, respectively. The total amounts of solutions needed for cleaning were 156.67 +/- 21.6, 195.0 +/- 20.0, 197.5 +/- 32.8, and 70.0 +/- 0.0 mL, respectively. Although there was no difference in cleaning time between the groups, the amount of solution required was significantly less in the DNP group (P = .02). In the proximal ileum segments, though there was no difference in carbachol responses between groups, KCl responses were significantly increased in the RL group (P < .05). When we evaluated the terminal ileum responses, carbachol responses were significantly increased in RL and PEG groups (P = .011) and decreased in the DNP group (P = .049). The KCl responses were also significantly increased in the R-L group with respect to the other groups (P < .05). Colon segments showed no difference in contractile responses with respect to different WGI solutions (P >.05, analysis of variance, post hoc Dunn's test). Conclusion: The different WGI solutions demonstrated no significant differences in colon contractions. The increased contractile responses in the proximal and terminal ileum segments after WGI with RL may be related to the electrolyte composition of RL. Although the lower amount of DNP solution required to achieve bowel cleaning seems to be an advantage, the decreased ileal contractions can be assessed as a disadvantage of DNP irrigations. (c) 2009 Elsevier Inc. All rights reserved.Öğe Esophageal and Gastric Smooth Muscle Activity After Carbon Dioxide Pneumoperitoneum(Academic Press Inc Elsevier Science, 2010) Soyer, Tutku; Aktuna, Zuhal; Aydos, Tolga Reşat; Osmanoğlu, Gökhan; Korkut, Oğuzhan; Akman, Hülya; Çakmak, MuratBackground. The metabolic changes associated with carbon dioxide (CO(2)) pneumoperitoneum include metabolic acidosis and lowered intra-abdominal pH values. An experimental study was performed to evaluate the effect of CO(2) pneumoperitoneum on esophageal and gastric smooth muscle sensitivity in response to several agonists. Methods. Wistar albino rats, weighing 200-250 g, were allocated into three groups. After anesthetization with ketamine hydrochloride and xylazine, abdominal esophagus, gastroesophageal junction, and gastric fundus were removed via median laparotomy in the control group. In the oxygen (O(2)) group, a 16G catheter was inserted into the abdomen above the umbilicus and insufflated with 95% O(2) and 5% CO(2) with a pressure of 10 mm Hg. In the CO(2) group, CO(2) was insufflated at the same pressure within the same time and the tissues were removed at the end of a 60 min period of pneumoperitoneum. Abdominal esophageal segment (n:6), gastroesophageal junction (n:6) and gastric fundus (n:12) were suspended under 0.5 to 2 g resting tension in Tyrode solution in organ baths. Contraction responses were obtained by carbachol and serotonin and relaxation responses were evaluated by isoproterenol in each group. All the responses were compared by nonparametric Kruskal Wallis test. Results. Carbachol and serotonin induced contractile responses of abdominal segments, gastroesophageal junction, and gastric fundus showed no difference between the control, O(2), and CO(2) groups (P > 0.05). Isoproterenol relaxation responses of the three groups were also not statistically different from each other (P > 0.05). Conclusion. CO(2) pneumoperitoneum of 60 min has no influence on esophageal and gastric smooth muscle responses to different agonists in rats. (C) 2010 Elsevier Inc. All rights reserved.Öğe 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, MuratAim: 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.
