title: Effects of levobupivacaine on isolated rat tracheal smooth muscle.
abstract: Levobupivacaine has been developed as a safer alternative to bupivacaine because of its reduced systemic toxicity. However, the effect of directly delivering levobupivacaine into tracheal smooth muscle has not been adequately explored. We performed this study to determine the in vitro effects of levobupivacaine on isolated rat tracheal smooth muscle. A portion of rat trachea 5 mm in length was mounted in 30 ml of Krebs solution in a muscle bath at 37 °C. The following effects of levobupivacaine were assessed: (1) the effect on tracheal smooth muscle resting tension (n = 6), (2) the effect on contraction caused by 10(-6) M methacholine (n = 6) and (3) the effect on electrically induced tracheal smooth muscle contractions (n = 6). Levobupivacaine caused dose-dependent relaxation in the trachealis muscle precontracted with 10(-6) M methacholine. Contraction inhibition was statistically significant when 10(-5) and 10(-4) M levobupivacaine were applied, compared with the contraction inhibition that occurred in the control groups (p < 0.01). A high dose of levobupivacaine also decreased the spike contraction induced by electrical field stimulation. This study indicated that high concentrations of levobupivacaine might antagonize the cholinergic receptors and inhibit parasympathetic function of the trachea.
authors.affiliation: Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.|Graduate Institute of Translational and Interdisciplinary Medicine, National Central University, Taoyuan, Taiwan.
authors.forename: Hung-Chi
authors.initials: HC
authors.lastname: Chang
authors.affiliation: Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: Shin-Yan
authors.initials: SY
authors.lastname: Chen
authors.affiliation: Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Huang
authors.affiliation: Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: Feng-Lin
authors.initials: FL
authors.lastname: Liu
authors.affiliation: Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan. stainless@s.tmu.edu.tw.|Department of Anesthesiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. stainless@s.tmu.edu.tw.
authors.forename: Yih-Giun
authors.initials: YG
authors.lastname: Cherng
authors.affiliation: Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. w0512n@ms15.hinet.net.|Department of Otolaryngology, Shuang Ho Hospital, Taipei Medical University, No. 291, Jhongjheng Rd., Jhonghe, Taipei, 23561, Taiwan. w0512n@ms15.hinet.net.
authors.forename: Hsing-Won
authors.initials: HW
authors.lastname: Wang
mesh_terms: D000818:Animals; D002045:Bupivacaine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004558:Electric Stimulation; D000077554:Levobupivacaine; D016210:Methacholine Chloride / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D051381:Rats; D014132:Trachea / Q000187:drug effects* / Q000378:metabolism
chemical_list: D016210:Methacholine Chloride; D000077554:Levobupivacaine; D002045:Bupivacaine
keywords: Electrical field stimulation; In vitro study; Levobupivacaine; Smooth muscle; Trachea