The effect of substance P on proliferation and proteoglycan deposition of cells derived from rabbit intervertebral disc.
METHODS
This study is an in vitro investigation of the effects of substance P on intervertebral disc cell metabolism.


OBJECTIVE
To determine whether the neuropeptide, substance P, affects cells isolated from the intervertebral disc.


BACKGROUND
Nerve fibers containing substance P are present in the anulus fibrosus and may be released from the nerve terminals as in other tissues. Substance P is mitogenic for a variety of immune and connective tissue cells, and a fragment of the peptide affects the metabolism of articular chondrocytes.


METHODS
Cells were isolated enzymically from the anulus fibrosus of intervertebral disc of 8-week-old rabbits. The effects of substance P and the C-terminal pentapeptide fragment SP7-11 on cell proliferation and proteoglycan deposition were determine by crystal violet and Alcian blue staining, respectively.


RESULTS
Substance P ((10)-11-(10)-7 mol/l) had a small stimulatory effect on disc cell proliferation. Proteoglycan deposition in the cell layer increased concomitantly. A greater proliferative effect was observed with substance P fragment 7-11 or with the addition of the neutral endopeptidase inhibitor, phosphoramidon.


CONCLUSIONS
Substance P has small mitogenic effects on rabbit intervertebral disc cells in vitro. Further investigation is required to establish whether this might have biologic relevance in relation to the maintenance or repair of the intervertebral disc.
Ashton
I K
IK
Centre for Spinal Studies, Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, United Kingdom.
Eisenstein
S M
SM
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D007403:Intervertebral Disc / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011509:Proteoglycans / Q000187:drug effects* / Q000378:metabolism*; D011817:Rabbits; D013373:Substance P / Q000494:pharmacology*
D011509:Proteoglycans; D013373:Substance P