The effects of substance P on the biomechanic properties of ruptured rat Achilles' tendon.
OBJECTIVE
To determine whether injection of substance P into the paratendinous region of a ruptured and subsequently sutured rat Achilles' tendon alters the biomechanic properties of the tendon.


METHODS
Interventional animal study.


METHODS
Animal laboratory at a university hospital.


METHODS
Ninety-six 2-month-old, male Sprague-Dawley rats.


METHODS
Injection of saline, substance P (10(-6)micromol/kg of body weight [BW] or 10(-8)micromol/kg BW) associated with neutral endopeptidase inhibitors, or neutral endopeptidase inhibitors alone into the paratendinous region of ruptured and subsequently sutured rat Achilles' tendons from the second until the sixth day postoperatively.


METHODS
Stress at maximal load and work to maximal load and stiffness.


RESULTS
Stress at maximal load was higher in the groups injected with substance P than in the saline group in the first, second, and sixth weeks. Work to maximal load was higher from the second until the sixth weeks in the substance P-treated groups than in the saline group. Stiffness did not differ between the 4 groups in any of the weeks.


CONCLUSIONS
Injection of substance P into the paratendinous region of ruptured and subsequently sutured rat Achilles' tendons improved tendon healing by enhancing stress at maximal load and work to maximal load. However, stiffness was not significantly affected.
Steyaert
Adelheid E
AE
Department of Physical Medicine and Rehabilitation, Ghent University Hospital, Belgium. Adelheid.Steyaert@Ugent.be
Burssens
Peter J
PJ
Vercruysse
Chris W
CW
Vanderstraeten
Guy G
GG
Verbeeck
Ronald M
RM
D000125:Achilles Tendon / Q000187:drug effects* / Q000293:injuries / Q000503:physiopathology; D000818:Animals; D001696:Biomechanical Phenomena; D002216:Captopril / Q000627:therapeutic use; D008297:Male; D018377:Neurotransmitter Agents / Q000627:therapeutic use*; D011480:Protease Inhibitors / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D012421:Rupture; D013314:Stress, Mechanical; D013373:Substance P / Q000627:therapeutic use*; D015244:Thiorphan / Q000627:therapeutic use; D014945:Wound Healing / Q000187:drug effects*
D018377:Neurotransmitter Agents; D011480:Protease Inhibitors; D013373:Substance P; D002216:Captopril; D015244:Thiorphan