PENTOXIFYLLINE INDUCES HYPERACTIVATION AND ACROSOME REACTION IN SPERMATOZOA OF GOLDEN-HAMSTERS CHANGES IN MOTILITY KINEMATICS

Pentoxifylline (PF) is used to enhance motility of spermatozoa from in fertile human subjects. We have previously shown that 0.45 mM PF impro ved capacitation of spermatozoa and fertilization of oocytes in vitro in hamsters. The present study was carried out to assess PF-induced ch anges in motility kinematics of hamster spermatozoa by a computer-aide d sperm analyser (CASA) and determine the timing of onset of hyperacti vation (HA) and acrosome reaction (AR) in PF-treated spermatozoa. Moti lity kinematics were analysed by CASA for 0-8 h in the absence or pres ence of 0.45 mM PF in Tyrode's medium supplemented with lactate, pyruv ate: and polyvinyl alcohol (TLP-PVA) or in TLP-PVA with bovine serum a lbumin (TALP-PVA). Conventional assessment was also made on the percen tage of motility and, quality of motility of spermatozoa; values were expressed as sperm motility index (SMT). Both in TALP-PVA and TLP-PVA, PF markedly increased SMI, especially the quality of motility (P < 0. 02) by 2-3 h which was sustained up to 6 h. The motility kinematic dat a of PF-treated spermatozoa in TALP-PVA showed that average path veloc ity, curvilinear velocity and amplitude of lateral head displacement s ignificantly (P < 0.05) increased as early as 2 h, with the expected d ecrease in straightness (STR) and linearity (LIN), Similar changes wer e also observed with PF-treated spermatozoa in TLP-PVA. Moreover, the percentage of hyperactivated spermatozoa in PF-treated samples Bras si gnificantly (P < 0.001) higher than the untreated control at 2 h. To d etermine whether PF could induce AR, independent of bovine serum album in, quantitative AR tvas assessed by observing the presence or absence of acrosomal cap on viable spermatozoa. PF significantly (P < 0.001) increased the percentage of AR as early as 2 h, reaching maximum se 4 h both in TALP-PVA (P < 0.05) and, in TLP-PVA (P < 0.001). These resul ts show that, in hamsters, PF induces early onset (by 2 h) of EIA and AR and increases the proportion of spermatozoa undergoing physiologica l maturation.