Increase by tubocurarine of [3H]acetylcholine release from the rat phrenic nerve after desensitization of nicotine receptors.
Tubocurarine reduced the neurally evoked [3H]acetylcholine release in the absence of nicotine, indicating positive nicotinic feedback. Tubocurarine, however, enhanced [3H]acetylcholine release after pretreatment with nicotine, a condition which causes desensitization of nicotine autoreceptors. After a nicotine-free period (15-60 min) during which the facilitatory autoreceptors could recover from desensitization, tubocurarine again reduced [3H]acetylcholine release. Protection of facilitatory nicotine autoreceptors from desensitization could explain the tubocurarine-induced increase in transmitter release.
Wessler
I
I
Department of Pharmacology, University of Mainz, F.R.G.
Apel
C
C
Hillen
U
U
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D008297:Male; D009538:Nicotine / Q000494:pharmacology; D010791:Phrenic Nerve / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011978:Receptors, Nicotinic / Q000187:drug effects*; D013569:Synapses / Q000187:drug effects; D014403:Tubocurarine / Q000494:pharmacology*
D011978:Receptors, Nicotinic; D009538:Nicotine; D000109:Acetylcholine; D014403:Tubocurarine