The effects of methylxanthines, ethymizol, ephedrine and papaverine on guinea pig and dog trachea
Language English Country Slovakia Media print
Document type Journal Article
PubMed
2820837
Knihovny.cz E-resources
- MeSH
- Cyclic AMP metabolism MeSH
- Bronchodilator Agents pharmacology MeSH
- Ephedrine pharmacology MeSH
- Etimizol pharmacology MeSH
- Histamine pharmacology MeSH
- Phosphodiesterase Inhibitors pharmacology MeSH
- Guinea Pigs MeSH
- Papaverine pharmacology MeSH
- Dogs MeSH
- Muscle Relaxation drug effects MeSH
- In Vitro Techniques MeSH
- Trachea drug effects physiology MeSH
- Xanthines pharmacology MeSH
- Animals MeSH
- Check Tag
- Guinea Pigs MeSH
- Male MeSH
- Dogs MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- Cyclic AMP MeSH
- Bronchodilator Agents MeSH
- Ephedrine MeSH
- Etimizol MeSH
- Histamine MeSH
- Phosphodiesterase Inhibitors MeSH
- methylxanthine MeSH Browser
- Papaverine MeSH
- Xanthines MeSH
The study was aimed to compare the effects of pentoxyphylline, aminophylline, choline theophyllinate and ethymizol on guinea pig and dog trachea with those of theophylline, papaverine and ephedrine. The effects of these drugs on the basal tension, on dose-response curves for muscle contraction produced by histamine and on cAMP level were investigated in guinea pig trachea, together with their influence on the resting and histamine-evoked mechanical and membrane activities of dog trachea. Like papaverine, pentoxyphylline did not alter the resting membrane potential, although it relaxed both tracheal preparations, and it antagonised the effects histamine and raised the cAMP level of the smooth muscle. The effects of ethymizol were similar to those of theophylline and its water soluble derivatives (aminophylline and choline theophyllinate). Whereas, ephedrine although it decreased the basal tension and inhibited histamine-evoked responses, also elicited substantial hyperpolarization of the smooth muscle membrane with no effect on the cAMP level. These findings are consistent with the hypothesis that cAMP has an important role in the action of some bronchodilator drugs; however, it is concluded that the possibility of contributing of their action on membrane potential to their action needs to be considered. The similarity of the potencies of ethymizol and pentoxyphylline to that of classical bronchodilators in inhibiting contraction of guinea pig and dog tracheal smooth muscle suggests that they may have a therapeutic value.