Premium
Substance P injections enhance tissue proliferation and regulate sensory nerve ingrowth in rat tendon repair
Author(s) -
Carlsson O.,
Schizas N.,
Li J.,
Ackermann P. W.
Publication year - 2011
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/j.1600-0838.2009.01080.x
Subject(s) - substance p , thiorphan , medicine , tendon , captopril , sensory nerve , tendinopathy , endocrinology , neuropeptide , achilles tendon , sensory system , urology , anatomy , neprilysin , chemistry , biology , receptor , neuroscience , biochemistry , blood pressure , enzyme
Tendon healing is characterized mostly by slow rehabilitation and, as in tendinopathy, aberrant, protracted sensory nerve ingrowth. This study investigated whether administration of the sensory neuropeptide substance P (SP) could enhance healing and modulate sensory nerve plasticity after Achilles tendon rupture. Fifty‐four male Sprague–Dawley rats were allocated to three groups, all receiving six daily injections post‐rupture of; (1) SP (10 −6 mol/kg body weight)+endopeptidase inhibitors captopril and thiorphan, (2) captopril/thiorphan only and (3) saline control. At 1, 3 and 6 weeks post‐rupture tendon healing was evaluated by assessments of fibroblast proliferation, collagen III‐LI (like) occurrence, diameter of newly organized collagen and sensory nerve fiber ingrowth. At 1 week, the SP‐treated group exhibited increased occurrence of collagen III‐LI ( P =0.03) and of organized collagen ( P =0.04) compared with control. At 3 weeks, the SP group notably displayed reduced SP‐nerve fiber ingrowth ( P =0.02), and higher fibroblast density ( P =0.004). Both the SP and captopril/thiorphan groups demonstrated increase in collagen fiber organization compared with control ( P =0.02 and 0.004, respectively). At 6 weeks, no significant differences were observed between the groups. SP supply in tendon repair promotes early tissue proliferation and regulation of endogenous sensory nerve ingrowth, suggesting implications for novel treatment in tendinopathy.