THE CORRELATION OF SPERM CHROMATIN DECONDENSATION FOLLOWING IN-VITRO EXPOSURE TO HEPARIN AND SPERM PENETRATION RATES

Purpose: The aim of this study was to evaluate the possible correlatio n of low-dose heparin-induced decondensation of sperm chromatin with s perm concentration, motility, morphology, membrane hypoosmotic respons e, ejaculate volume and the ability of sperm to penetrate zone-free ha mster oocytes, Methods: Twenty-two donors of known fertility and 105 p atients undergoing evaluation at an andrology laboratory were evaluate d by standard World Health Organization semen analysis techniques and a modified sperm penetration assay (SPA). An aliquot was also incubate d for 60 min and Ham's F10 medium containing 50 USP/ml heparin. The pe rcentage of sperm undergoing chromatin decondensation was evaluated an d correlated to SPA rates and semen quality parameters. Results: No si gnificant correlation was observed between semen parameters and decond ensation rates A nonsignificant (P = 0.11) inverse correlation (P = -0 .21) was observed between SPA rates and chromatin decondensation. Sign ificant (P < 0.001) differences were observed in the decondensation ra te of donors (3.7 +/- 0.6), patients with normal SPA rates (7.8 +/- 1. 5), and patients with decreased SPA rates (21.7 +/- 1.8). The deconden sation rates were significantly different (P < 0.01) between patients with a normal SPA rate and patients with a decreased SPA rate. Conclus ions: These data indicate a significant inverse relationship between t he SPA rate, which has previously been shown to correlate highly with fertilization ability, and heparin-induced sperm chromatin decondensat ion.