Changes in cholinergic and nitrergic systems of defunctionalised colons after colostomy in rabbits

• Published in: The Journal of surgical research 2016
• Main Authors: Moralıoğlu, Serdar, MD, Vural, İsmail Mert, MD, Özen, İbrahim Onur, MD, Öztürk, Gökçe, MD, Sarıoğlu, Yusuf, MD, Başaklar, Abdullah Can, MD
• Format: Article
• Language: English
• Subjects: Surgery
• ISSN: 0022-4804
• DOI: 10.1016/j.jss.2016.08.032

Abstract Background This study was designed to assess smooth muscle function and motility in defunctionalised colonic segments and subsequent changes in pathways responsible for gastrointestinal motility. Methods Two-month-old New Zealand rabbits were randomly allocated into control and study groups. Sigmoid colostomies were performed in the study group. After a 2-month waiting period, colonic segments were harvested in both groups. For the in vitro experiment, the isolated circular muscle strips which were prepared from the harvested distal colon were used. First, contraction responses were detected using KCl and carbachol; relaxation responses were detected using papaverine, sodium nitroprusside, sildenafil and l -arginine. The neurologic responses of muscle strips to electrical field stimulation (EFS) were evaluated in an environment with guanethidine and indomethacin. EFS studies were then repeated with atropine, Nω-nitro- l -arginine methyl ester ( l -NAME), atropine and l -NAME added environments. Results Although macroscopic atrophy had developed in the distal colonic segment of the colostomy, the contraction and relaxation capacity of the smooth muscle did not change. EFS-induced nitrergic-peptidergic, cholinergic-peptidergic and non-cholinergic non-nitrergic responses significantly decreased at all frequencies (0.5–32 Hz) in the study group compared with those in the control group (P