Abstract
There have been some articles in regard to the pharmacological study on the extraocular muscles. Katz and Eakins (1) reported the in situ effect of drugs on electrically stimulated extraocular muscle of cats, and Kern (2, 3) studied the effect of sympathomimetic amines on the isolated extraocular muscles.
However, there has been no publication, to our knowledge, in regard to the electrical stimulation of the isolated extraocular muscle-nerve preparations. The investigations on the neuromuscular junction in the extraocular muscle were generally carried out in the in situ experiments. In the in situ experiments a part of responses of the extraocular muscles to drugs may be due to secondary effects accompanied with responses of the intraocular muscles to the drugs. In the present study, the effects of drugs on the electrically stimulated extraocular muscle-nerve preparations isolated from rabbits were investigated and were compared with actions of the drugs in the in situ experiments. Furthermore, actions of drugs on the isolated extraocular muscles were examined.