The role of free-radical oxidation in the initiation of apoptotic blood leukocytes death in the dynamics of experimental mechanical non-penetrating corneal injury

ABSTRACT

The objective of the study was to investigate the features of free-radical oxidation and apoptotic leukocyte death in the dynamics of mechanical non-penetrating corneal injury in rabbits.

Material and methods. The peculiar features of free-radical oxidation (the content of TBA-reactants and Schiff bases) in blood and aqueous humor were determined using biochemical methods. The analysis of blood leukocytes samples to determine reactive oxygen species was evaluated by the flow laser cytometry method, using 2.7-dichlorodihydrofluorescein diacetate. The percentage of apoptotic blood leukocytes was evaluated by the flow laser cytometry method, using specific kit.

Results. In case of experimental non-penetrating mechanical corneal injury, the percentages of reactive oxygen species and spontaneous apoptosis of blood leukocytes increased significantly from the 3^rd day of the experiment, with the highest values within 14^th and 21^st days of observation. Also, the intensification of lipid peroxidation  (increased content of TBA- reactants and the Schiff bases) in blood and aqueous humor, with a maximal increase on the 14^th day of observation (p<0.05), has been observed. The strongest correlations between the percentage of apoptotic blood leukocytes, the content of TBA-reactants and the percentage of ROS were observed within the 7^th-14^th days of the experiment.

Conclusions. One of the important signaling pathway of blood leukocytes apoptosis triggering in case of mechanical non-penetrating corneal injury in rabbits is reactive oxygen species overproduction and possible disruption of the mitochondrial inner membrane (direct relationship between the increase of TBA-reactants, reactive oxygen species and percentage of annexin-positive blood leukocytes (r=0.99; p<0.05)).

Keywords: corneal injury, rabbits, leukocytes, reactive oxygen species, apoptosis.

Corresponding author:
Мariya MARUSHCHAK
Dept. of Functional and Laboratory Diagnosis, I. Horbachevsky Ternopil State Medical University
Address: Majdan Voli 1, Ternopil 46001, Ukraine
E-mail: marushchak@tdmu.edu.ua