Acrosin activity in patients with idiopathic infertility.

Acrosin is a sperm acrosomal enzyme that is involved in the acrosome reaction, the binding of spermatozoa to the zona pellucida, and fertilization. This study was designed to determine whether sperm acrosin measurements can identify subpopulations of infertile or subfertile patients that are not recognized by routine semen analyses. We measured the total acrosin activity of ejaculates in a group of 19 men (15 suspected subfertile patients and 4 fertile donors). The acrosin activity was measured in liquefied semen specimens using the methodology described by Kennedy et al. [1989) J Urol 10:221-231). Ten patients in the suspected subfertile group had a mean acrosin value of 7.8 microIU acrosin/million sperm, which is clearly in the abnormal range (less than 14 microIU/10(6) sperm). Three patients had a mean acrosin value of 20.1 microIU/10(6) sperm, which is in the indeterminate range. Two other patients and four proven fertile donors had acrosin values in the normal range (greater than 25 microIU/10(6) sperm) (Agarwal A, Loughlin KR (1990): 2d International Meeting of Andrology, Como, Italy; Abstr 22). The normal fertile controls had a mean acrosin value of 32.5 microIU/10(6) sperm.