Effects of Jakyakgamchotang Extract on the Trachea Smooth Muscle

The purpose of the present study is to determine the effect of Jakyakgamchotang on histamine or acetylcholine induced tracheal smooth muscle contraction in rats and guinea pigs. Guinea pig(500g, male) and Sprague Dawley rats(250g, male) were killed by exposure and a segment (4-5mm) of the thoracic trachea from each rat and guinea pig was cut into equal segments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force displacement transducers under 0.5g loading tension. The dose of histamine(His) which evoked 50% of maximal response() was obtained from cumulative dose response curves for histamine(). Contractions evoked by His() were inhibited significantly by Jakyakgamchotang. In guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was 90.8% (p〈0.001) after Jakyakgamchotang. In rat tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was 22.1% (p〈0.05) after Jakyakgamchotang. Propranolol indomethacin and methylene blue() slightly but significantly attenuated the inhibitory effects of Jakyakgamchotang. These results indicate that Jakyakgamchotang can relax histamine or acetylcholine induced contraction of guinea pig and rat tracheal smooth muscle.