Background: Bupivacaine is an amide-linked local anesthetic that has been used in subcutaneous infiltration, epidural and peripheral nerve block for surgery over three decades. Several studies have suggested that inhaled local anesthetics can reduce respiratory reflexes. To assess the direct actions of bupivacaine on airway smooth muscle we used our preparation to examine the effectiveness of bupivacaine on isolated rat trachea. Methods: A 5-mm-long portion of rat trachea was mounted in Krebs solution at 37°C. Changes in tracheal contractility in response to a parasympathetic mimetic agent and electrical stimulation were measured using a transducer connected to a Pentium III computer equipped with polygraphy software. The following assessments were done: (1) effect of bupivacaine on the resting tension of tracheal smooth muscle; (2) effect of bupivacaine on contraction caused by exposure to 10 -6M methacholine as a parasympathetic mimetic; (3) effect of bupivacaine on electrically induced contraction of tracheal smooth muscle. Results: Bupivacaine had a negligible effect on the basal tracheal tension as the concentration increased. Bupivacaine inhibited the tracheal smooth muscle contraction in response to methacholine and electrical stimulation in a concentration-dependent manner. Conclusion: The study indicates that bupivacaine might inhibit cholinergic neurotransmission and have an anti-spasmic effect on the trachea, in that it inhibited the contractions elicited by electrical field stimulation and a depolarizing agent.
|Number of pages||4|
|Journal||Journal of Experimental and Clinical Medicine(Taiwan)|
|Publication status||Published - Feb 2012|
- Invitro study
- Smooth muscle
ASJC Scopus subject areas