The effects of nifedipine on respiratory mechanics investigated by theend-inflation occlusion method in the rat

Context: Calcium channel blockers may theoretically exhibit relaxing effects not only on vascular smooth muscle but also on airway smooth muscle. Objective: To investigate possible effects of nifedipine on respiratory mechanics in the rat. Methods: Respiratory system mechanical parameters were measured by the end-inflation occlusion method in the rat in vivo before and after the intraperitoneal administration of nifedipine. Results: We found that nifedipine affects respiratory mechanics, inducing a reduction of airway resistance and of respiratory system elastance, probably because of a relaxing action on airway and parenchimal smooth muscle cells. Conclusion: Should these results be further confirmed by human investigations, a possible role of nifedipine in pharmacological respiratory system’s diseases treatment may be suggested.