Abstract

Objectives: To study the protective effects of propofol against bronchoconstriction produced by bradykinin.
Methodology: Guinea pig trachea was first dissected and cut into 2-3mm wide rings. The trachea was then placed in Krebs Henseleit solution. The tracheal muscle activity was recorded by Research Grade Isometric Force Transducer DT-475 (USA) on power lab data acquisition unit. Effect of increasing concentration of Acetylcholine and bradykinin were recorded and cumulative dose response curves were plotted. Acetylcholine was taken for comparison purposes and its response was considered to be 100 percent. Propofol was then added in fixed concentration to study its effect on tracheal muscle.
Results: Acetylcholine and bradykinin produced reversible contraction at maximum mean±SEM of 0.015±0.0006 mV and 0.014±0.0007 mV. Propofol showed relaxation of the guinea pig tracheal muscle in a fixed dose of 22 µM at a maximum mean±SEM value of 0.006±0.0004 mV producing a maximum response of 38 percent and shifting the dose response curve to the right and downwards.
Conclusion: Propofol significantly ameliorated the bronchoconstriction produced by bradykinin showing that the mechanism of tracheal relaxation in asthmatic individuals can be through the inhibition of bradykinin mediator.

Key words: Bradykinin, propofol, trachea, bronchodilation.