Andrology: Variability of human sperm response to immediate and prolonged exposure to pentoxifylline

Abstract

Pentoxifylline improves some motility characteristics of human spermatozoa, but the variability of response to this drug has not been clearly defined. We used computer-assisted sperm motion analysis to examine the in-vitro response of spermatozoa to pentoxifylline. Individuals (n = 31) with normal sperm counts were randomly selected and their spermatozoa exposed to different concentrations of pentoxifylline. Further tests on a subgroup of individuals examined the longevity of spermatozoa in response to this agent. Straight line velocity (VSL) was only improved at 0.1 mM and the major effect of the drug was on curvilinear velocity (VCL) and lateral head displacement (ALH). Prolonged exposure to pentoxifylline enhanced sperm motion only at 0.1 mM. Higher concentrations produced dose-dependent detrimental effects on all the motion characteristics. There was considerable inter-individual variability in both VCL and ALH response ranging from little or no detectable response to a 40% increase above control value. The maximum response was most commonly seen at a concentration of 2 mM pentoxifylline.

Andrology: Pentoxifylline-supplemented cryoprotectant improves human sperm motility after cryopreservation

“…These findings differ from previous studies using cryopreserved human spermatozoa (Wang et al, 1993) and washed fresh spermatozoa (Moohan et al, 1993), in that a lower concentration of pentoxifylline was found to be optimal. However, considerable inter-individual variability in response to pentoxifylline has been reported which has not been adequately explained (Moohan et al, 1993). In our study, substantial inter-individual variation in response to pentoxifylline-supplemented cryoprotectant was observed (unpublished data).…”

Pentoxifylline acts synergistically with A23187 to increase the penetration of zona‐free hamster oocytes by cryopreserved human spermatozoa

“…Pentoxifilline and other phosphodiesterase inhibitors are well known to stimulate the motility of spermatozoa, especially when it is poor initially (Garbers et al, 1971; Aitken et al, 1983; Rees, et al, 1990). More recent studies with computerized motility analyses agree that the greatest effects are on curvilinear velocity (VCL) and lateral head displacement (ALH), leading some authors to conclude that pentoxlfylline increases the proportion of hyperactivated spermatozoa (Tesarik et al, 1992a;Kay et al, 1993;Lewis et al, 1993;Mbizvo et al, 1993;Moohan et al, 1993;Pang et al, 1993). However, in the present study, in the presence of A23187 which has a deleterious effect on sperm mothty (Ford et al, 1991;McLaughlin et al, 1993), both 0.6 and 3.6 mmol pentoxifylline per litre fkrther decreased the proportion of spermatozoa which were motile.…”

The Role of PDE5 Inhibitors in the Treatment of Testicular Dysfunction

“…PTX has been considered to stimulate flagellar motility by increasing sperm intracellular cAMP (Stefanovich, 1973;Garbers & Kopf, 1980;Tash & Means, 1983;Ward & Clissold, 1987) as well as by reducing sperm intracellular superoxide anion and reactive oxygen species known to damage DNA (Lopes et al, 1998;Twigg et al, 1998). In particular PTX in both in vivo and in vitro studies, appears to increase significantly beat cross frequency, curvilinear velocity, and the percentage of hyperactivated spermatozoa (Rees et al, 1990;Shen et al, 1991;Lewis et al, 1993;Moohan et al, 1993;Pang et al, 1993;Tournaye et al, 1994;Centola et al, 1995;Paul et al, 1996;Nassar et al, 1999).…”