RELATIONSHIP BETWEEN RESAZURIN REDUCTION TEST, REACTIVE OXYGEN SPECIES GENERATION, AND GAMMA-GLUTAMYL-TRANSFERASE

The production of reactive oxygen species (ROS) from spermatozoa has b een measured by chemiluminescence in the two fractions of a Percoll gr adient column (47 and 90%). Chemiluminescent signals were recorded in each fraction after addition of luminol and horse-radish peroxidase (b asal state), and after stimulation with formyl-methionyl-leucyl-phenyl -alanine (FMLP) and phorbol ester (PMA). We found an inverse correlati on between the reducing capacity of the semen as estimated by the resa zurin test, and the production of ROS by the spermatozoa, especially a fter stimulation with PMA (r = 0.51, P <0.001). gamma-glutamyltransfer ase activity of seminal plasma was inversely correlated with ROS (r = -0.47, P < 0.01) and the resazurin test result (r = -0.43, P < 0.001) suggesting a possible role of prostatic secretions in the protection o f spermatozoa against oxygen radicals. The resazurin test has a positi ve predictive value of 92.5% at a criterion value of colour scale 4 to discriminate between normal and excessive ROS production by spermatoz oa, with sensitivity 79% and specificity 74%. In addition, at criterio n value of colour scale 3, the resazurin test could distinguish betwee n samples with normal or low activity of gamma-glutamyltransferase, wi th sensitivity 57% and specificity 93%. It is concluded that the resul t of the resazurin test can be influenced by the oxidative stress of s permatozoa and by prostatic function.