Lipid peroxidation in human spermatozoa and maintenance of progressive sperm motility

Washed and deep frozen spermatozoa of 46 patients from an infertility clini c were separated into 3 different groups depending on their progressive mot ility (expressed as the sperm motile efficiency index according to Ishii et al., 1977), determined 0 and 3 h after liquefaction, and were examined for their lipid peroxidation (LPO) potential by means of the thiobarbituric ac id assay. Spontaneous and iron-catalysed generation (after 15, 30 and 60 mi n incubation) of thiobarbituric acid-reactive substances (TBARS) was measur ed spectrophotometrically. Spontaneous LPO revealed the highest generation of TBARS in the group of spermatozoa with initially normal progressive moti lity and decreased maintenance of progressive motility after 3 h of aerobic incubation. Iron-catalysed LPO generally revealed the highest amounts of T EARS after 60 min; especially in the aforementioned group with decreased mo tility maintenance. The differences between this group and the two other gr oups were highly significant. Consequently, spermatozoa with initially norm al progressive motility but decreased maintenance of motility, generated hi gher amounts of stable LPO products than others, which suggests that loss o f motility under aerobic incubation seems to be the consequence of enhanced LPO processes.