Depletion of substance P from rat primary sensory neurons by ATP, an implication of P2X receptor-mediated release of substance P.
Effects of ATP on substance P immunoreactivity were examined in cultured dorsal root ganglion neurons. We found that treatment of dorsal root ganglion neurons with ATP significantly depleted substance P immunoreactivity on the neurites and somata of the neurons. The effects of ATP were significantly inhibited by the purinergic P2 receptor antagonists suramin (30 microM) and pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (10 microM). We also showed that ATP-induced depletion of substance P immunoreactivity from dorsal root ganglion neurons depended on the entry of Ca(2+). In a spinal cord slice preparation, we also found the internalization of neurokinin-1/substance P receptors in many dorsal horn neurons following the application of ATP or alpha,beta-methylene-ATP. Together these results indicate that activation of P2X receptors may result in release of substance P from primary afferent neurons.
Nakatsuka
T
T
McKnight Brain Institute of the University of Florida and Division of Neuroscience, Department of Oral Surgery, University of Florida, Box 100416, Gainesville, FL 32610, USA.
Mena
N
N
Ling
J
J
Gu
J G
JG
D000255:Adenosine Triphosphate / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology / Q000378:metabolism; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009475:Neurons, Afferent / Q000378:metabolism*; D020671:Posterior Horn Cells / Q000378:metabolism; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D051381:Rats; D017207:Rats, Sprague-Dawley; D018040:Receptors, Neurokinin-1 / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D013373:Substance P / Q000378:metabolism*
D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D018040:Receptors, Neurokinin-1; D018048:Receptors, Purinergic P2; D013373:Substance P; D000255:Adenosine Triphosphate