J Korean Ophthalmol Soc.  2003 Oct;44(10):2402-2409.

The Changes of Myosin Heavy Chain Isoforms after Tenotomy on Extraocular Muscle Layers of Rabbits

• Lee HC
• Oh SY
• Chang BL

Abstract

PURPOSE
Extraocular muscle (EOM) consists of two layers, the global and the orbital layer, which are readily distinguished by their histopathology. This study was conducted to investigate the changes of myosin heavy chain (MHC) and MHC isoforms of the global and the orbital layers of EOM after tenotomy. METHODS: Twenty four New Zealand white rabbits were used. The rectus muscles were harvested on day 3, week 1, week 2, week 3, week 4, and week 8 after EOM tenotomy. The change of MHC amount was measured using an electrophoresis. The changes of MHC isoforms were also measured quantitatively using western blot immunostaining.
RESULTS
The amount of total MHC, fast MHC isoform, and slow MHC isoform decreased maximally at 1-week after EOM tenotomy and recovered at 4-week and 8-week after tenotomy. There was no significant change in the amount of the neonatal and developmental MHC isoform.
CONCLUSIONS
Fast and slow MHC isoform changed mainly due to the changes in the global layer rather than in the orbital layer after EOM tenotomy.

Keyword

Extraocular muscle; Global layer; Myosin heavy chain; Orbital layer; Tenotomy

MeSH Terms

Blotting, Western
Electrophoresis
Muscles
Myosin Heavy Chains*
Myosins*
Orbit
Protein Isoforms*
Rabbits*
Tenotomy*
Myosin Heavy Chains
Myosins
Protein Isoforms