Action of metallic ions on the precocious development by rabbit sperm of motion patterns that are characteristic of hyperactivated motility

Abstract

An earlier study demonstrated that rabbit sperm incubated for 16 hr under capacitation conditions acquire motility patterns identical to those seen in rabbit sperm capacitated in vivo. We now show that similar motion patterns develop after 0.5 hr incubation in a Tris-buffered medium, medium M. Development and decline of the motion patterns occurred in three phases each recognized by the character of the biphasic motion patterns. Hyperactivated sperm were objectively identified and quantified by a previously developed computer-directed model. The percentage of motile sperm that acquired hyperactivated motility and the period they remained in this state varied among sperm from different rabbits. The decline in hyperactivated motility was paralleled by a decrease in the average sperm curvilinear velocity (VCL) and average amplitude of lateral head displacement (AALH), but was not accompanied by a concomitant decrease in percentage of motile sperm. Pb2+ and Cd2+, at concentrations that did not inhibit motility, prevented development of hyperactivated motility. Inhibition of hyperactivated motility by Pb2+ was time- and concentration-dependent; the average percentage of hyperactivated sperm decreased from approximately 30% to < 5% (n = 5) in 1 hr at a Pb2+ concentration of 25 microM. Cd2+ inhibition of hyperactivation was dependent only on concentration of the cation. At a concentration of 100 microM, the decrease in the percent of hyperactivated sperm was approximately 50% (n = 3). Hg2+, Zn2+, and Cr6+ at sublethal concentrations had no effect on hyperactivated motility development. These results suggest that Pb2+ and Cd2+, by virtue of their ability to prevent the wide curvature flagella beating that is characteristic of hyperactivation, can compromise fertilization at concentrations that do not inhibit sperm motility and act as a reproductive toxicant at a level other than spermatogenesis.

Rabbit semen fertility after heterospermic insemination with spermatozoa of different capacitation time

“…Η αντιμετώπιση του προβλήματος της μειωμένης γονι μότητας του σπέρματος κουνελιού λόγω πρώιμης ή καθυ στερημένης έναρξης ενεργοποίησης των σπερματοζωα ρίων του, αποτελείτο αντικείμενο πρόσφατων ερευνών που έχουν ως στόχο την ανεύρεση in vitro μεθόδων ανα στολής ή επιτάχυνσης της παραπάνω διαδικασίας 15 . Η ε-τεροσπερμική σπερματέγχυση με σπερματοζωάρια ποικί λων χρόνων ενεργοποίησης δίνει τη δυνατότητα μιας πιο πρακτικής λΰσης, δεδομένου ότι βελτιώνει τη γονιμότητα του σπέρματος, ιδιαίτερα μάλιστα στις περιπτώσεις όπου η σπερματέγχυση σε συγκεκριμένο χρόνο πριν από την ωο-θυλακιορρηξία δεν είναι δυνατή.…”

Sperm Chromatin Structure Is Altered in Cynomolgus Monkeys With Environmentally Relevant Blood Lead Levels

“…These authors propose that lead interferes with fertilization through inhibition or delay of sperm nuclear decondensation. In addition, it has recently been suggested (Young et al, 1995) that lead compromises fertility via inhibition of hyperactivation of sperm motility. Therefore, it is proposed that low and moderate BLLs may adversely affect sperm function of monkeys in the absence of demonstrable effects on spermatogenesis using conventional methods of analysis.…”