The influence of animal species on the relationship between ATP-sensitive potassium ion channels and defense reflexes of the airways.

BACKGROUND

The ATP-sensitive potassium ion channels (K+ATP) are widely expressed on airway sensory nerves that mediate cough and other protective reflexes; dependent on airways smooth muscles (ASM) reactivity.

OBJECTIVE

The study was conducted to determine the involvement of K+ATP in airway sensory nerves activity of different animal species.

METHODS

In this study we have evaluated the cough reflex inhibiting potential and modulation of ASM reactivity in vitro, by K+ATP opener-pinacidil in guinea pig and cats. The cough in guinea pig was induced by administration, in cats by mechanical stimulation of the airways. ASM reactivity was tested by organ tissue both method of 0.3 M citric acid aerosol at 3 min interval.

RESULTS

1. Pinacidil inhibits cough reflex in guinea pigs which was antagonized when pre-treated with K+ATP blocker glibenclamide. 2) Pinacidil exhibited antitussive activity in cats comparable to codeine and was noticeably higher than dropropizine effects. 3) ASM reactivity was significantly abolished by pinacidil and almost completely antagonized by glibenclamide in guinea pigs. 4) Pinacidil significantly attenuated ASM contraction in cats only in highest concentrations of contractile mediators.

CONCLUSION

K+ATP may be involved in mechanisms of cough reflex, likewise in antitussive activity of several more agents and also on defence reflexes dependent on ASM reactivity in different animal species such as guinea pigs and cats (Fig. 8, Ref. 20). Full Text (Free, PDF) www.bmj.sk.