[A combination of timoptol and L-arginine HCl: a regulator of intraocular pressure in rabbits].

In our experimental study were determined changes IOP an pupil after application mixture of aminoacid 10% L-arginine.HCl in 0.5% Timoptol into the conjunctival sac of left eye of 5 healthy albinotic rabbits (the New-Zeland White species). The right eye was control. Our results proved that the mixture of 0.5% Timoptol with 10% L-arginine.HCl has significantly decreases IOP against the control eye during the whole experiment. The maximum of decrease IOP was reached in 60th min. (20.1%; 4 torr) and in 240th min. (10.7%; 2.1 torr). In comparison with effect of mixture of both compartments, the 10% L-arginine.HCl and 0.5% Timoptol applicated alone caused only non-significant IOP decrease. Papilar diameter in both eyes were identical (7-7.5 mm) during the whole experiment. We suggest that the interaction of L-arginine.HCl with Timoptol causes formation of the new metabolite which is, in fact already effective component; this new substance decreases production of aqueous humor of corpus ciliare and the IOP is decreased in this way in physiological conditions. Utilization of this knowledge in clinical conditions could contribute to better utilization and more harmless use of antiglaucomatics in glaucoma disease therapy. For that reason, more longtime studies should be performed to evaluate the effect of this new metabolite in local application.