Dana A. Ohl, M.D.¹ and Alan C. Menge, Ph.D.²

¹ Section of Urology, 1500 E. Medical Center Drive, Ann Arbor, MI 48109-0330

² F4826 Mott Hospital, 1500 East Medical Center Drive, Ann Arbor, MI 48109-0272

Received 07/31/96; Accepted 07/31/96; On-line 09/01/96

6. THERAPIES AND FUTURE DIRECTIONS

ICSI is one of the major advances in the treatment of male infertility and has overcome severe male factor problems. However, all cases of male factor do not require ICSI. Semen specimens with low motility or forward progression may respond to methylxanthine reagents stimulation of the cAMP system such as caffeine, 2-deoxyadenosine, and pentoxifylline. Evidence is mounting that these treatments may be effective in some cases of male infertility and in improving IVF results (93, 94). The pentoxifylline treatment appears to improve the acrosome reaction and in vitro fertilization rates in those cases in which the sperm had failed the ionophore A23187 challenge test (94, 95). Pentoxifylline also improves motility parameters and hyperactivation of sperm from both normal and asthenozoospermic semen (96) and increases sperm binding to the zona pellucida in the hemizona assay of some men (97).

The future availability of recombinant ZP3 protein should allow development of an AR assay which will be dependent on the natural inducer of the phenomenon and that would render specificity to the methodology (15). With the availability of specific sperm molecules for sperm-zona pellucida binding, it would be possible to determine the complete profile of the ability of sperm to interact with the egg.

Sperm coated with a high number of antisperm antibodies are inhibited from interacting with the egg. Attempts to remove such antibodies by washing, enzyme digestion and low pH media have largely failed. Identification of sperm antigens involved in immunologic infertility will allow molecular cloning of the genes and production of recombinant peptides/proteins that may facilitate removal of antibodies from sperm cells and allowing them to fertilize the egg.

Our understanding of the processes of sperm function and how these processes may become disordered is increasing rapidly. With each new discovery, we have a new potential opportunity to impact a great many couples suffering from male factor infertility.