Seminal acid phosphatase in relation to fertility

In a study involving 176 males attending an infertility clinic and 88 controls awaiting elective vasectomy, the semen acid phosphatase activity was found to be significantly higher in the former group (p less than 0.001). However, no definite relationship of semen acid phosphatase level to ejaculate volume, sperm motility, viability, morphology, seminal zinc, magnesium or fructose was observed in either group. The distribution of acid phosphatase in the males attending the infertility clinic, unlike that of the controls, was found to be bimodal. 32 presumably infertile males had acid phosphatase values exceeding the control mean +/- 2 SD. These 32 nevertheless did not have a significantly different mean ejaculate volume, sperm motility, morphology or viability, when compared with the group with normal acid phosphatase levels. Causes of the bimodal distribution of concentrations of acid phosphatase are discussed.