Tappenbeck K, Hoppe S, Geburek F, Feige K, Huber K
Department of Physiology, University of Veterinary Medicine, Bischofsholer Damm 15, D-30173 Hannover, Germany.
Clinic for Horses, University of Veterinary Medicine, Bünteweg 9, D-30559 Hannover, Germany.
Vet J. 2014 Sep;201(3):423-6. doi: 10.1016/j.tvjl.2014.05.014. Epub 2014 May 15.
By blocking the enteric nervous system (ENS) using tetrodotoxin (TTX), previous studies have documented the contractility-enhancing (CE) effects of lidocaine in equine intestinal smooth muscle (SM) at the level of SM cells and/or interstitial cells of Cajal (ICC). The present study examined the impact of ENS deactivation on CE lidocaine effects, and investigated the effects of lidocaine on ENS activity. TTX application did not affect the CE effects of lidocaine, indicating that these were not mediated by TTX-sensitive sodium channels. Application of TTX or ≥100 mg/L lidocaine reduced ENS activity. Although such concentrations of lidocaine exceed therapeutic blood concentrations, tissue concentrations may be higher with the potential to reduce ENS activity and impair intestinal motility in vivo. Improved understanding of underlying mechanisms is relevant for therapeutic use of lidocaine in horses with postoperative ileus.
通过使用河豚毒素（TTX）阻断肠神经系统（ENS），先前的研究已经证明利多卡因在马肠道平滑肌（SM）细胞和/或 Cajal 间质细胞（ICC）水平上具有增强收缩性（CE）的作用。本研究考察了 ENS 失活对利多卡因 CE 效应的影响，并研究了利多卡因对 ENS 活性的作用。应用 TTX 并不影响利多卡因的 CE 效应，表明这些效应不是由 TTX 敏感的钠通道介导的。应用 TTX 或≥100 mg/L 利多卡因可降低 ENS 活性。尽管如此浓度的利多卡因超过了治疗血药浓度，但体内组织浓度可能更高，有可能降低 ENS 活性并损害肠道蠕动。深入了解其潜在机制对于利多卡因在术后肠梗阻马匹中的治疗应用具有重要意义。
