THE ACROSOME REACTION RESPONSE ASSAY - A NEW WAY TO IDENTITY PATIENTSIN WHOM PENTOXIFYLLINE WOULD IMPROVE THE HUMAN FOLLICULAR FLUID-INDUCED ACROSOME REACTION

The effect of pentoxifylline on the spontaneous and follicular fluid ( hFF)-induced acrosome reaction (AR) was studied in an attempt to ident ify those patients who would benefit from the use of pentoxifylline as an AR-stimulating agent. Pentoxifylline (1 mg/ml) produced no signifi cant increase over spontaneous AR at any of the time points studied (6 0 min: 6.2% +/- 2.0 spontaneous AR vs 7.4% +/- 2.0 pentoxifylline AR; 120 min: 7.1% +/- 1.6 spontaneous vs 9.0% +/- 2.5 pentoxifylline; 180 min: 7.0% +/- 1.8 spontaneous vs 10.9% +/- 4.0 pentoxifylline, n = 6). On the other hand, hFF produced a significant increase in AR (6.9% sp ontaneous Ai vs 11.2% hFF AK, p < 0.001, n = 39) and this effect was e nhanced by pre-incubation with pentoxifylline (15.0% pentoxifylline hFF AR vs 11.2% hFF AR, p < 0.001). There were no differences in perce ntage AR induced by hFF or pentoxifylline + hFF between patients with normal (n = 16) and abnormal (n = 25) semen samples. Individual analys is of the effects of hFF and pentoxifylline + hFF on AR showed seat va riability between patients and enabled us to classify them into four c ategories: inducible-responder (15%), non-inducible-responder (23%), i nducible-non-responder (41%) and non-inducible-non-responder (21%). An induction index (II) (induction produced by hFF divided by spontaneou s AK) and a response index (RI) (induction produced by pentoxifylline + hFF divided by hFF) were calculated for each sample. Patients previo usly classified as inducible exhibited an II > 0.30 and patients previ ously classified as responders showed an RI > 0.26. There was no corre lation between II and RI values (Spearman, r = -0.185, p = 1). Our res ults show that pentoxifylline is an enhancer of the induced AR only in some patients. We propose an 'AR response assay' to identify responde r patients and thus enable rational use of this drug.