Fructolysis in Human Spermatozoa Under Normal and Pathological Conditions

Anaerobic fructolysis was studied in human spermatozoa from 1) normal, 2) oligospermic, and 3) necrospermic semen, as well as 4) in normal spermatozoa irreversibly immobilized with a spermicidal agent (lipid peroxide); the rate of fructolysis was determined by measuring the amount of L‐(+)‐lactic acid produced during anaerobic incubation in fructose‐supplemented sperm suspensions with identical concentrations of spermatozoa and fructose. Motile spermatozoa from normal semen produced lactic acid at a steady rate for at least 2 hours at 37 C, but when immobilized with peroxidized linoleic acid they lost rapidly and irreversibly all fructolytic ability. There was no substantial difference in the rates of anaerobic fructolysis between sperm suspensions prepared 1) from six individual specimens of normal semen and 2) from pooled ejaculates of ten oligospermic patients. In three of a group of four infertile men diagnosed as necrospermic, the immotile spermatozoa failed to produce lactic acid from fructose. In the fourth individual, the spermatozoa, although immotile at the time of testing, were able to convert fructose to lactic acid, but at a reduced rate; this patient's semen has been examined periodically over the last three years and has contained mostly immotile spermatozoa, but a few times motility was definitely observed, especially after treatment with caffeine. The authors conclude from their results that necrospermia may be associated with diverse metabolic defects, one of them being loss of fructolytic ability by human spermatozoa.