Reinnervation of laryngeal muscles: a study of changes in myosin heavy chain expression.
Direct repair of the recurrent laryngeal nerve (RLN) results in synkinesis and compromised laryngeal function. We have therefore developed a pig model to investigate whether anastomosis of the phrenic nerve with the abductor branch of the RLN leads to specific reinnervation of abductor muscles. Expression of myosin heavy chain protein (MyHC), a marker of appropriate reinnervation, was determined in the posterior cricoarytenoid (PCA) abductor and thyroarytenoid (TA) adductor muscles following nerve injury and repair. The denervated PCA muscle exhibited decreased levels of the fast-type MyHC isoforms IIA and IIB, and increased slow-type MyHC expression. Similarly, there was a fall in type IIB levels in the denervated TA muscle but increases in both IIA and slow MyHC. Four months after repair, the MyHC expression in the PCA was near normal, suggesting that our model reduces the risk of synkinesis and ensures the accurate muscle reinnervation required for full functional recovery.
Kingham
Paul J
PJ
Blond McIndoe Research Laboratories, Plastic and Reconstructive Surgery Research, Stopford Building, University of Manchester, Oxford Road, Manchester M13 9PT, UK. paul.j.kingham@manchester.ac.uk
Birchall
Martin A
MA
Burt
Rachel
R
Jones
Alan
A
Terenghi
Giorgio
G
D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D005786:Gene Expression Regulation / Q000502:physiology*; D007821:Laryngeal Muscles / Q000294:innervation* / Q000378:metabolism*; D009121:Muscle Denervation; D018995:Myosin Heavy Chains / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D013552:Swine; D013997:Time Factors
D020033:Protein Isoforms; D018995:Myosin Heavy Chains