Spinal substance P immunoreactivity is enhanced by acute chemical stimulation of the rat prostate.
OBJECTIVE
To investigate the role substance P (SP) plays in prostatic inflammation, we evaluated SP immunoreactivity within the spinal cord after irritation of the prostate. Because alpha-adrenergic blockade attenuates nociceptor-induced pain, the effects of an alpha-adrenergic blocker on SP immunoreactivity were also evaluated. SP is considered a mediator of nociception in the spinal cord. Immunoreactivity of SP is enhanced after acute chemical stimulation of somata.


METHODS
Rats received chemical irritation of the prostate with or without pretreatment with tamsulosin. They were killed after 1 hour, and immunohistochemical staining for SP was performed. SP immunoreactive areas were quantified in the dorsal spinal cord of the L5 to S2 segments.


RESULTS
Chemical irritation of the prostate increased SP immunoreactive areas in the L6 to S2 segments. Enhancement was observed in the whole dorsal spinal cord regions. This enhancement was significantly attenuated by tamsulosin in the L6 and S1 segments.


CONCLUSIONS
SP probably plays a significant role in mediating nociceptive processing from the prostate. Tamsulosin can attenuate nociception-induced SP upregulation within the spinal cord.
Ishigooka
Manabu
M
Department of Urology, Yamagata University School of Medicine, Yamagata, Japan.
Nakada
Teruhiro
T
Hashimoto
Tohru
T
Iijima
Yoshiaki
Y
Yaguchi
Hiromasa
H
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D005404:Fixatives / Q000494:pharmacology; D005557:Formaldehyde / Q000494:pharmacology; D008159:Lumbar Vertebrae; D008297:Male; D010146:Pain / Q000378:metabolism; D011467:Prostate / Q000528:radiation effects*; D011469:Prostatic Diseases / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012445:Sacrococcygeal Region; D013116:Spinal Cord / Q000737:chemistry* / Q000187:drug effects; D013268:Stimulation, Chemical; D013373:Substance P / Q000032:analysis* / Q000502:physiology; D013449:Sulfonamides / Q000494:pharmacology; D000077409:Tamsulosin; D015854:Up-Regulation
D000317:Adrenergic alpha-Antagonists; D005404:Fixatives; D013449:Sulfonamides; D005557:Formaldehyde; D013373:Substance P; D000077409:Tamsulosin