Use of theophylline to enhance sperm function.

Poor sperm motility is an important factor in male infertility. Preliminary results in our laboratory on a group of 19 men (10 suspected infertile men and 9 fertile donors) showed stimulation of sperm fertilizing ability after sperm washing with theophylline as demonstrated by zona free hamster egg penetration test. The egg penetration rate for the control spermatozoa samples from subfertile men was 16%. Incubation with theophylline (10 mM) increased the penetration rate to 46%, whereas semen incubation with theophylline (20 mM) increased the penetration rate to 51%. A similar twofold increase in egg penetration was observed in the semen of fertile men incubated with theophylline of similar concentrations. Subfertile patients with ejaculate volumes of less than or equal to 1 ml or total motile sperm count of less than or equal to 10 x 10(6)/mL or increased semen viscosity did not exhibit beneficial effects with theophylline washing as measured by hamster egg penetration test score. The increase in percentage of penetrated eggs with theophylline use in both fertile and subfertile men was significant at 10 mM concentration (p less than .001) and 20 mM (p less than .001) when compared to control (untreated) samples. No significant difference in penetration rate was seen between 10 and 20 mM theophylline concentrations. It appears that theophylline may be useful in improving the fertilizing capacity of selected human semen samples with poor motility and poor penetration ability under artificial insemination conditions.