Effect of FK506 on functional recovery after facial nerve injury in the rat.
OBJECTIVE
To examine the effect of the immunosuppressive agent FK506 on the rate of functional recovery of the rat facial nerve after crush injury.


METHODS
Forty rats underwent facial nerve crush injury and were randomly assigned to 4 experimental groups: isotonic sodium chloride solution control, FK binding protein 52 (FKBP-52) antibody control, FK506, and FK506 and FKBP-52 antibody. Rats underwent daily recovery testing from postoperative day 9 until postoperative day 21 by videotaping 3 validated variables in this model: blink reflex return, vibrissial fibrillation loss, and return of vibrissial sweeping symmetry.


RESULTS
FK506-treated animals demonstrated improved recovery in all 3 variables compared with control animals. The FK506 and FKBP-52 antibody group demonstrated improved recovery of only the return of the blink reflex.


CONCLUSIONS
FK506 accelerated functional recovery of facial nerve function after crush injury. Neuroregeneration was inhibited by FKBP-52 antibody in the rat midface but not the upper face. FK506 may be a viable adjuvant treatment for facial nerve neurapraxic injury.
Yeh
Cory
C
Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, 243 Charles St, Boston, MA 02114, USA. cyeh@partners.org
Bowers
Daniel
D
Hadlock
Tessa A
TA
D000818:Animals; D001767:Blinking / Q000187:drug effects; D020220:Facial Nerve Injuries / Q000188:drug therapy*; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use*; D007273:Injections, Intramuscular; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000187:drug effects*; D016559:Tacrolimus / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use*
D007166:Immunosuppressive Agents; D016559:Tacrolimus