Adenosine 5'-triphosphate inhibits slow depolarization induced by repetitive dorsal root stimulation via P2Y purinoceptors in substantia gelatinosa neurons of the adult rat spinal cord slices with the dorsal root attached.
We previously reported that slow depolarization of substantia gelatinosa neurons is evoked by repetitive stimulation of C-fibers of dorsal root in adult rat spinal cord transverse slices with the dorsal root attached, which was considered to be an event relevant to spinal nociception. In the present study, we investigated the effects of adenosine 5'-triphosphate (ATP) and its analogs on the slow depolarization. ATP (10-100 microM) significantly inhibited the amplitude of slow depolarization in a concentration-dependent manner. The inhibitory effect of ATP was not reversed by suramin, an antagonist for some P2-purinoceptors, and was mimicked by a P2Y selective agonist uridine 5'-triphosphate, but not a P2X selective agonist alpha,beta-methylene ATP. These results suggest that ATP inhibits the slow depolarization of substantia gelatinosa neurons relevant to nociceptive transmission in the spinal dorsal horn, via suramin-insensitive P2Y purinoceptors.
Yoshida
Kohei
K
Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan.
Nakagawa
Takayuki
T
Kaneko
Shuji
S
Akaike
Akinori
A
Satoh
Masamichi
M
D000200:Action Potentials / Q000187:drug effects* / Q000502:physiology; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects* / Q000502:physiology; D009619:Nociceptors / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010146:Pain / Q000378:metabolism / Q000503:physiopathology; D017729:Presynaptic Terminals / Q000187:drug effects / Q000378:metabolism; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000187:drug effects; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D058472:Receptors, Purinergic P2Y1; D013126:Spinal Nerve Roots / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013376:Substantia Gelatinosa / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013498:Suramin / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
D018691:Excitatory Amino Acid Antagonists; C546384:P2ry1 protein, rat; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D016194:Receptors, N-Methyl-D-Aspartate; D018048:Receptors, Purinergic P2; D058472:Receptors, Purinergic P2Y1; D013498:Suramin; D000255:Adenosine Triphosphate