The effects of adrenergic and adrenergic blocking agents on the phosphorylase activity of bovine extraocular muscles

ABSTRACT

The author investigated the effect of adrenergic and adrenergic blocking agents on the phosphorylase activity of bovine extraocular muscle in vitro and obtained the following results: 1. The phosphorylase a activity of bovine extraocular muscle was revealed 53.6% in vitro. 2. The phosphorylase a activity of bovine extraocular muscle was slightly enhanced by the adrenergic agents such as epinephrine, norepinephrine and isoproterenol. 3. The phosphorylase a activity of bovine extraocular muscle was not affected by the adrenergic areceptor blocking agent, phenoxybenzamine but slightly inhibited by the adrenergic beta-receptor blocking agent, propranolol. 4. The phosphorylase a activity of bovine extraocular muscle previously treated with the adrenergic agents was blocked by a sole administration of propranolol or combined administrations of propranolol and phenoxybenzamine but not blocked by phenoxybenzamine alene.