Modulation of cholinergic responsiveness through the beta-andrenoceptor signal transmission pathway in bovine trachealis

The effects of pharmacological stimulation at different levels of the [beta]-adrenoceptor (AR) pathway, including the receptor, the receptor-coupled Gs protein, and adenylyl cyclase, were studied by simultaneous measurements of acetylcholine (ACh) release and isometric force evoked by electric stimu...

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Published inJournal of applied physiology (1985) Vol. 95; no. 2; p. 735
Main Authors Brichetto, Lorenzo, Song, Pingfang, Crimi, Emanuele, Rehder, Kai, Brusasco, Vito
Format Journal Article
LanguageEnglish
Published Bethesda American Physiological Society 01.08.2003
Subjects
Calcium
Cattle
Pharmacology
Potassium
Respiratory system
Throat
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Summary:The effects of pharmacological stimulation at different levels of the [beta]-adrenoceptor (AR) pathway, including the receptor, the receptor-coupled Gs protein, and adenylyl cyclase, were studied by simultaneous measurements of acetylcholine (ACh) release and isometric force evoked by electric stimulation in isolated bovine trachealis. The [beta]-AR agonists isoproterenol (10-6 and 10-5 M) and salbutamol (10-7 to 10-5 M) significantly attenuated both ACh release and contractile force. Forskolin, at 10-6 M, significantly increased ACh release without effect on contractile force, whereas at 10-5 M it increased ACh release but significantly decreased force. Activation of Gs protein by cholera toxin (10 micro g/ml) significantly attenuated both ACh release and contractile force, but its effect on ACh release was abolished by calcium-activated potassium (KCa)-channel blocker iberiotoxin (10-7 M). The KCa-channel opener NS-1619 (10-4 M) attenuated significantly both ACh release and contractile force. It is concluded that [beta]-AR agonists attenuate cholinergic neurotransmission in isolated bovine trachealis model by a mechanism not involving cAMP but KCa channels. [PUBLICATION ABSTRACT]
ISSN:8750-7587
1522-1601