Nerve growth factor treatment enhances release of immunoreactive calcitonin gene-related peptide but not substance P from spinal dorsal horn slices in rats.
The effect of systemic nerve growth factor (NGF) on neuropeptide content and capsaicin-evoked release of neuropeptide from in vitro spinal cord dorsal horn slices was examined. Rats were injected subcutaneously every other day with murine NGF (mNGF) 1 mg/kg or saline for 7 days, or mNGF 0.1/kg, mNGF 1 mg/kg or saline for 13 days. Lumbar dorsal horn slices of the rat spinal cord from all groups showed a significant increase in immunoreactive calcitonin gene-related peptide (CGRP) release upon exposure to capsaicin. This release was enhanced in rats pretreated with mNGF 1 mg/kg for 7 days, but not after 13 days. No enhancement was seen after 7 or 13 days in any treatment group for immunoreactive substance P release. Upon examination of neuropeptide content in dorsal horn, no significant differences were noted between treatment groups. The increased iCGRP release from dorsal horn slices suggests a preferential release of CGRP and provides further evidence that NGF indirectly plays a role in the modulation of inflammation through the regulation of neuropeptide release.
Bowles
Walter R
WR
Department of Restorative Sciences, University of Minnesota, Minneapolis, MN, USA.
Sabino
Ma'Lou
M
Harding-Rose
Catherine
C
Hargreaves
Kenneth M
KM
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D002211:Capsaicin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004347:Drug Interactions; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009414:Nerve Growth Factors / Q000494:pharmacology*; D020671:Posterior Horn Cells / Q000187:drug effects* / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000166:cytology*; D013373:Substance P / Q000378:metabolism*
D009414:Nerve Growth Factors; D013373:Substance P; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin