Contractile properties of single skinned fibres from the extraocular muscles, the levator and superior rectus, of the rabbit.

Abstract

1. The superior rectus and levator palpebrae superioris (levator), two of the extraocular muscles, were dissected from the rabbit and stored in a glycerol‐based solution at ‐20 degrees C in order to prepare single, skinned fibres. 2. The Ca(2+)‐ and Sr(2+)‐activated isometric contractile properties were determined for individual extraocular muscle fibres. Fibres were separated into discrete groups or fibre types on the basis of their physiological characteristics. The superior rectus and levator muscles were both found to consist of fibres which exhibited similar contractile characteristics to fast‐ and slow‐twitch fibres from other mammalian muscle, including type I, type IIA and type IIB f..