Based on experiments with rabbit eyes (strain New Zeeland white)the authors submit evidence that the metabolite which is formed as a result of interaction of 2% pilocarpine and L-lysine 2 HCl.2H 2 O has a significantly greater and more rapid effect on the development of miosis than 2% pilocarpine alone. The amino acid lysine does not have a miotic effect. The authors explain the bioactivity of the new metabolite, its effect during the development of miosis and reduction of intraocu- lar pressure. They emphasize a greater and more rapid bioactivity of the new metabolite as compared with pilocarpine. These results provide evidence that during treatment of primary glaucoma it is important to consider not only the effect on reduction of intraocular pressure but also physiological processes which develop in tissue structures after administration of different chemotherapeutic agents.

        Key words: bioactivity and cholinergic action of the metabolite of pilocarpine and L-lysine 2HCl.2H 2 O, miosis and effect on intraocular pressure, treatment of glau- coma