A quantitative method for determining the effects of drugs on spermatozoal motility

The purpose of this study was to demonstrate whether the turbidimetric method of measuring sperm motility could be used to quantitate the effects of drugs. Human ejaculate was layered on the bottom of a cuvette containing Lopata's medium, and sperm motility was measured spectrophotometrically. The slope of the initial increase in absorbance (OD) is directly proportional to the rate at which the fastest fraction of sperm enters the light path and provides a highly reproducible measure of sperm motility. The effects of caffeine and imipramine on sperm motility were studied. The test drug was added to the buffer before the semen was introduced so that the assay would measure the immediate effect of the drug on the sperm. Caffeine produced a dose-dependent increase in sperm motility, and imipramine produced a dose-dependent decrease. We conclude from these studies that the turbidimetric assay is capable of providing a rapid, reproducible, quantitative analysis of the effects of drugs on sperm motility.