The author studied the effects of adrenergic and its blocking agents, ACTH, methylprednisolone, 3-hydroxytryptamine, and prostaglandin El and E2 on the phosphorylase activity in bovine ciliary muscle in vitro and obtained the following results.
1. The phosphorylase activity in bovine ciliary muscle rias enhanced by the adrenergic agents, such as epinephrine, norepinephrine and isoproterenol, but was not affected by adrenergic alpha receptor blocking agents, such as phenoxybenzamine and phentolamine, and adrenergic beta receptor blockades, such as propranolol and pronethalol. Pretreatment with propranolol prevented partly the epinephrine-induced increase of the phosphorylase activity in bovine ciliary muscle.
2. The phosphorylase activity in bovine ciliary_muscle was shown to be stimulated by ACTH, methylprednisolone and 5-hydroxytryptamine but not by prostaglandin EI and E2
3. The phosphorylase activity in bovine ciliary muscle which was stimulated by epinephrine, ACTH, methylprednisolone or 5-hydroxytryptamine was markedly blocked by pretreatment with prostaglandin El but less by prostaglandin E2.
4. Prostaglandin El exerted no effects on the phosphorylase activity in bovine ciliary muscle following the addition of cyclic AMP or Mg++-ATP, but markedly depressed that stimulated by epinephrine.
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