[Studies on human spermatozoal acrosome using spermac stain in fertile and infertile men including two cases of round-headed spermatozoa].

Using a new acrosome stain named "Spermac stain", the relationship between the staining rate of sperm acrosome and conventional semen parameters, i.e., sp. density and sp. motility efficiency index (SMEI) was studied. The mean positive staining rate of sp. acrosome in ten fertile men was 81.5%. In 72 infertile men, a significantly higher (p less than 0.001) correlation was noted between the positive staining rate and sp. density and SMEI. 5 out of 8 male partners of unexplained infertility couples showed low staining rates (40-60%), in spite of normal sp. density and SMEI. Ejaculates from two infertile men with "round-headed" spermatozoa were examined by Spermac stain and electron microscopy. The staining rates of sp. acrosome in these two cases were 4.5% and 16.5%. The fine structures of the sperm and the spermatid were presented. Because Spermac stain is quick, reliable and easy to use, this staining method is recommended for evaluating sp. acrosomal morphology in practical use.