Effects of adenosine on cholinergic transmission in mammalian vesical parasympathetic ganglia.
Intracellular recordings were made from mammalian vesical parasympathetic ganglia. A fast excitatory postsynaptic potential (EPSP) was abolished by hexamethonium (200 microM) in rabbit and feline ganglia. A slow inhibitory postsynaptic potential (IPSP) and a following slow EPSP were abolished by atropine (1 microM) in the feline ganglia. Bath application of adenosine (300 microM) depressed the amplitude of nicotinic fast EPSP by 48 +/- 4% in the rabbit ganglia. The action of adenosine was dose-dependent. An antagonist of A1-purinoceptors, 8-cyclopentyltheophylline (1-10 microM), inhibited the adenosine-induced depression but not the amplitude of fast EPSP. Adenosine (2-3 mM) did not significantly affect either the muscarinic slow IPSP, or the slow EPSP, in the feline ganglia. Adenosine also caused a hyperpolarization (1-5 mV) in 40% of the rabbit neurons and 66% of the feline neurons. However a purinergic IPSP was not recorded from either species. These data suggest diverse actions of adenosine in modulating cholinergic transmission in rabbit and feline vesical ganglia.
Nishimura
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Department of Physiology, Tokai University School of Medicine, Kanagawa, Japan.
D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D002415:Cats; D019706:Excitatory Postsynaptic Potentials; D005260:Female; D005726:Ganglia, Parasympathetic / Q000187:drug effects / Q000502:physiology*; D018738:Hexamethonium / Q000494:pharmacology; D007001:Hypogastric Plexus; D066298:In Vitro Techniques; D008297:Male; D018733:Nicotinic Antagonists / Q000494:pharmacology; D058915:Purinergic P1 Receptor Antagonists; D011817:Rabbits; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D009435:Synaptic Transmission / Q000187:drug effects*; D013806:Theophylline / Q000031:analogs & derivatives / Q000494:pharmacology
D018733:Nicotinic Antagonists; D058915:Purinergic P1 Receptor Antagonists; D018047:Receptors, Purinergic P1; C053907:8-cyclopentyl-1,3-dimethylxanthine; D018738:Hexamethonium; D013806:Theophylline; D000241:Adenosine