Stereoselective Activity of Tratinterol to Relax Small Airway and Inhibit Allergic Mediator Release

To compare the effect of tratinterol hydrochloride (SPFF) and its enantiomers for improving the lung resistance and inhibiting the release of allergic mediators. Lung overflow test in guinea pig was conducted and results illustrated that (-)SPFF and (±)SPFF could significantly inhibit the increase of lung outflow induced by histamine, while (+)SPFF did not show the effect. Inflammatory mediator release from allergic lung tissues was determined and we found that (±)SPFF showed the best activity among all the tested compounds, while the effect of (-)SPFF and (+)SPFF was equal. Left atria cardiac contractility in guinea pig was performed to determine the receptor selectivity of the compounds. Results indicated all the compounds had high affinitys to β₂ receptor. In conclusion, considering pharmacodynamic properties, (-)SPFF was superior to (+)SPFF, while for mechnism and receptor selectivity, (-)SPFF and (+)SPFF had no significant difference.