Potentiation of sympathetic neuromuscular transmission mediated by muscarinic receptors in guinea pig isolated vas deferens.
In guinea-pig isolated vasa deferentia, purinergic neurogenic contractions and responses to applied adenosine 5'-triphosphate (ATP) were potentiated by carbachol; responses to adrenergic transmission and applied noradrenaline were not. Following blockade of P2 receptors and alpha-adrenoceptors, the residual neurogenic response was massively potentiated by carbachol, suggesting the presence of a non-purinergic, non-adrenergic component. In the presence of guanethidine, carbachol had no significant effect, indicating that sympathetic transmission was the only element involved. Use of oxotremorine and selective muscarinic receptor antagonists suggested that the potentiating effect of carbachol and oxotremorine was mediated via M3 muscarinic receptors without involvement of nicotinic receptors.
Iram
Samera
S
Department of Anatomy and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK.
Hoyle
Charles H V
CH
D000109:Acetylcholine / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D018679:Cholinergic Agonists / Q000494:pharmacology*; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology*; D058919:Purinergic P2 Receptor Antagonists; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D043587:Receptor, Muscarinic M3 / Q000819:agonists* / Q000032:analysis; D058469:Receptors, Purinergic P2X; D014649:Vas Deferens / Q000187:drug effects* / Q000294:innervation*
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D018679:Cholinergic Agonists; D018727:Muscarinic Antagonists; D058919:Purinergic P2 Receptor Antagonists; D043587:Receptor, Muscarinic M3; D058469:Receptors, Purinergic P2X; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; D011732:Pyridoxal Phosphate; D000255:Adenosine Triphosphate; D000109:Acetylcholine; D009638:Norepinephrine