Acrosin Activity in Patients with Idiopathic Infertility

Abstract

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 μJU acrosin/million sperm, which is clearly in the abnormal range (<14 μ/10⁶ sperm). Three patients had a mean acrosin value of 20.1 μIU/10⁶ sperm, which is in the indeterminate range. Two other patients and four proven fertile donors had acrosin values in the normal range (>25 μIU/10⁶ 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 μIU/10⁶ sperm.

Key Words:

• Acrosin
• Fertilization
• Male infertility