Noradrenaline-ATP corelease and cotransmission following activation of nicotine receptors at postganglionic sympathetic axons.
In rabbit mesenteric arteries, nicotine-evoked vasoconstrictor responses were markedly reduced by prazosin, slightly reduced after desensitization by alpha, beta-methylene ATP, and abolished by combined treatment with prazosin and alpha, beta-methylene ATP. In guinea-pig vasa deferentia preincubated with [3H]noradrenaline, nicotine elicited contractions as well as an overflow of tritium and of ATP. The contractions were greatly reduced by prazosin and abolished after additional desensitization by alpha, beta-methylene ATP. The nicotine-induced overflow of tritium was not changed by either treatment. The overflow of ATP was decreased by prazosin but not diminished further after additional desensitization by alpha, beta-methylene ATP. Activation of prejunctional nicotine receptors elicits a corelease of noradrenaline and ATP which leads to cotransmission in both tissues.
Starke
K
K
Institute of Pharmacology, Freiburg, Federal Republic of Germany.
Bültmann
R
R
Bulloch
J M
JM
von Kügelgen
I
I
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D001369:Axons / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005728:Ganglia, Sympathetic / Q000502:physiology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D009538:Nicotine / Q000378:metabolism* / Q000494:pharmacology*; D011224:Prazosin / Q000494:pharmacology*; D011817:Rabbits; D011978:Receptors, Nicotinic / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects*; D014649:Vas Deferens / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects*
D011978:Receptors, Nicotinic; D009538:Nicotine; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D011224:Prazosin