HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Eusebi, F Articles by Zani, B M Search for Related Content PubMed PubMed Citation Articles by Eusebi, F Articles by Zani, B M

Istituto di Istologia ed Embriologia Generale, Roma, Italy.

1. Single-channel currents induced by acetylcholine (ACh) were recorded from unstriated and non-innervated embryonic chick myotubes using the cell-attached patch-clamp technique. 2. ACh applied to the non-patched membrane decreased both channel opening probability and conductance. These ACh-induced effects occurred also when the non-patched membrane was exposed to nominally Ca2+-free extracellular medium, but were absent when it was treated with curare. 3. ACh-induced membrane current recorded under whole-cell patch-clamp conditions decreased in amplitude and time course when myotubes were intracellularly loaded with guanosine-5'-O-(3-thiotriphosphate) GTP gamma S), but not with guanosine-5'-O-(2-thiodiphosphate) (GDP beta S) or cyclic adenosine-5'-monophosphate (cyclic AMP). Internal perfusion of GTP gamma S affected the ACh-induced openings in a similar manner to the non-patch ACh application. 4. These results suggest that ACh, in addition to its direct effect, acts indirectly on the nicotinic receptor channels by delivering an intracellular messenger and through the activation of a putative G protein.