Activation of trigeminal nociceptive neurons by parotid PAR-2 activation in rats.
To clarify involvement of protease-activated receptor-2 (PAR-2) in parotid pain, we examined whether PAR-2 activation in the parotid gland could activate trigeminal nociceptive neurons in anesthetized rats, by analyzing immunoreactive Fos as a nociceptive marker. Either the PAR-2 agonist SLIGRL-NH2 or capsaicin, injected into the parotid duct, caused expression of Fos in the trigeminal subnucleus caudalis, although the PAR-2-inactive reversed peptide had no such effect. The Fos expression caused by PAR-2 activation was inhibited by ablation of capsaicin-sensitive sensory neurons. Intraductal SLIGRL-NH2 did not increase vascular permeability in the parotid gland. Our data thus reveal that activation of PAR-2 in the parotid gland can cause activation of trigeminal nociceptive neurons via capsaicin-sensitive sensory nerves most probably by a non-inflammatory mechanism.
Kawabata
Atsufumi
A
Division of Physiology and Pathophysiology, School of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan. kawabata@phar.kindai.ac.jp
Itoh
Hideki
H
Kawao
Naoyuki
N
Kuroda
Ryotaro
R
Sekiguchi
Fumiko
F
Masuko
Takashi
T
Iwata
Koichi
K
Ogawa
Akiko
A
D000818:Animals; D002211:Capsaicin / Q000494:pharmacology; D002452:Cell Count / Q000379:methods; D004347:Drug Interactions; D007839:Functional Laterality; D007150:Immunohistochemistry / Q000379:methods; D066298:In Vitro Techniques; D008297:Male; D008526:Medulla Oblongata / Q000166:cytology; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009619:Nociceptors / Q000378:metabolism; D009842:Oligopeptides / Q000494:pharmacology*; D016761:Oncogene Proteins v-fos / Q000378:metabolism; D010306:Parotid Gland / Q000294:innervation / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D044463:Receptor, PAR-1 / Q000235:genetics / Q000378:metabolism; D044464:Receptor, PAR-2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013997:Time Factors; D012668:Trigeminal Ganglion / Q000166:cytology*
D009842:Oligopeptides; D016761:Oncogene Proteins v-fos; D012333:RNA, Messenger; D044463:Receptor, PAR-1; D044464:Receptor, PAR-2; C112356:seryl-leucyl-isoleucyl-glycyl--arginyl-leucinamide; D002211:Capsaicin