Purpose: To examine the effectivity of the antiglaucomatic Timoptol mixture with amino acid L-taurine.HCl on physiological values of the IOP in rabbits. Methods: The experimental work was performed on 5 female rabbits of the New Zealand White species. Into the left conjunctival sac at 8oo was applicated: a) the 10% L-taurine.HCl in 0.5% Timolol; b) the 0.5% Timolol alone; c/ the 10% Ltaurine. HCl alone. The IOP was measured before and in 5th, 15th, 30th, 60th, 120th, 180th and 240th min. and 24 hours after the instillation. The right eye was used as control. Results: a) The 10% L-taurine.HCl in 0.5% Timolol showed also significant IOP decrease (without 5th min.) in all measured times with maximum in 180th min. (with value of decrease 6.7 torr) and in 24th hours the decreased showed still significantly lower level – 3.3 torr; b) The antiglaucomatic 0.5%Timolol alone decreased the IOP values compared with the control eye without significance. The IOP values from the 60th min. were nearly linear character (the mean decrease compared with the control eye was only 1 torr); c) The 10% amino acid L-taurine.HCl showed in all measured times only no significant decrease of the physiological IOP. Conclusions: The results proved that in the mixture of antiglaucomatic Timoptol and amino acid Taurine a new biologically active substance, the bioregulator is created by interaction. This metabolite as “bioantiglaucomatic” showed several times higher effect on the IOP decrease compared with Timolol or Taurine alone. The showed effect on IOP based on interaction of amino acid mixture with antiglaucomatic is specific and efficacy together with duration changed according the type of amino acid.

        Key words: the amino acid Taurine and antiglaucomatic Timoptol mixture as bioregulator of the rabbits IOP