Abstract
This study was carried out to investigate the effect of Shihogigiltang extract on the contractile force of the isolated guinea pig trachea smooth muscle and elucidate its mechanism. The results were obtained as follows: 1. The isolated trachea smooth muscle was suspended in the organ bath with oxygenated Kreb's Henseleit bicarbonate buffer solution at $37^{\circ}C$, and the developed tension by the drug was recorded with isometric transducer(Nacro F-60). The resting tension was approximately 0.5g. 2. The trachea smooth muscle of the isoiated guinea pig was significantly relaxed by the administration of Shihogigiltang extract. 3. ShihogigiItang significantly inhibited the contractile response of histamine 10-4 M is isolated guinea pig trachea smooth muscle. 4. The contractile response of the trachea smooth muscle of the isolated guinea pig by acetylcholine 10-4 M was significantly inhibited by Shihogigiltang extract. 5. The contractile response of the trachea smooth muscle of the isolated guinea pig by 5-hydorxytryptamine 10-4 M was significantly inhibited by Shihngigiltang extract. 6. The contractile response of the trachea smooth muscle of the isolated guinea pig by prostaglandin $F2\;{\alpha}$ 10-7 M was significantly inhibited by Shihngigiltang extract.