[Oxidation of pyridine nucleotides in injuries of the cornea].

NADH fluorescence may serve a convenient test indicating the tissue redox status. Rabbit cornea has been incubated at ambient temperature in media of different compositions with 5.10(-5) M NADH at pH 7.0-7.3. Oxidation of NADH in the humor-substituting medium for corneal tissue incubation has been monitored by fluorescent analysis (stimulation maximum at a wavelength of 360 nm, emission maximum 460 nm). Characteristic kinetics of changes in the pyridine nucleotide fluorescence consists in its maximum intensity occurring in 10 min of the tissue incubation, followed by the fluorescence intensity reduction by the 20-30th min of the corneal tissue incubation. These changes are explained by a release of substrates, characterized by NADH oxidizing activity, from the corneal tissue, this resulting from injury to the corneal cells with humor-substituting solutions. Carnosine (10 mM) and taurine (0.05% solutions) have been found to protect the corneal tissue from injuries, in contrast to common salines.