The gamma-Subunit of the Acetylcholine Receptor Is Not Expressed in the Levator Palpebrae Superioris

Abstract

Article abstract-In extraocular muscle (EOM), expression of the gamma-subunit, which is associated with the fetal-type acetylcholine receptor (AChR), may offer a differential target for immune-mediated damage and could explain the preponderance of ocular manifestations caused by myasthenia gravis (MG). Using Poly(A) sup + RNA hybridization, we investigated expression of the gamma-subunit in bovine levator palpebrae superioris (LP), a muscle also differentially involved by MG. There were no transcripts of the gamma-subunit of the AChR, but the epsilon-subunit, associated with the adult-type AChR, was present. The results indicate that the susceptibility of LP to MG is not mediated by gamma-subunit expression and suggest that multiterminal fibers in EOM may be the site of gamma-subunit expression.NEUROLOGY 1995;45: 516-518