Objective evaluation of the morphology of human epididymal sperm heads.

Spermatozoa were obtained from nine epididymal regions of six epididymides taken from five men undergoing castration for prostatic carcinoma (53-76 years) and from one man with testicular cancer (38 years). Spermatozoa were obtained by mincing tissue in phosphate-buffered saline, making air dried smears and staining with Hemacolor. The percentage of sperm heads categorised subjectively as normal (of uniform shape) or otherwise was calculated for each region. This confirmed that grossly swollen sperm heads (previously shown to be artefacts) were only present in proximal regions of the duct. A computer-aided sperm morphology analyser (Sperm Class Analyzer(R)) was used to provide objective measurements of sperm head area, perimeter, length and width of the uniform sperm heads and revealed that there was a gradual and statistically significant decline in sperm head size upon maturation, as occurs in other species. There was no significant difference between the morphometric parameters of spermatozoa obtained from the distal cauda epididymis and those obtained from the ejaculates of young normozoospermic patients.