Preliminary study of water and some element contents in boar spermatozoa, before, during and after freezing

Abstract

Boar semen was analysed by electron microscopy coupled to image analysis and X-ray energy dispersive spectroscopy, during the usual process for freezing and thawing in field conditions. Freeze-substitution and freeze-quenching permitted recording of real or potential intracellular ice before, during, and after freezing. Heads and flagella displayed two different osmotic properties before freezing. Heads were dehydrated progressively before and during freezing, while flagella were hydrated before freezing and were only dehydrated during freezing. All parts of the thawed cells were rehydrated. Ice crystal damage was mostly present in frozen mitochondria and axonemes and the acrosomes were strongly affected by thawing. The total amounts of Na, Cl, Ca, K, Mg, and Zn per cell were only elevated in frozen and thawed midpieces while the heads were permeable both to water and elements at that time.

Modifications of bull spermatozoa induced by three extenders: Biociphos, low density lipoprotein and Triladyl, before, during and after freezing and thawing

“…The results were more homogeneous latter. Acrosomal destructions could result from intrusion of Ca 2þ , which is present in high concentrations in egg yolk (Handbook of Chemistry and Physics 1990) and rapidly enters the cells when the temperature is below 30 8C (Courtens et al 1989). The next event, a massive destruction of plasma membranes, leaving less than 20% of cells intact after 24 h, can be compared to that observed after adding milk lipases to goat spermatozoa (Courtens et al 1984).…”

Cryopreservation alters the Ca2+ flux of bovine spermatozoa

“…Robertson et al 1990), of warm-shocking resulting from the thawing (Bamba and Cran 1988;Vorotilin et al 1991) or an effect of the freezing medium. The whole milk commercial extender in which the spermatozoa were cryopreserved contains approximately 119 mg of Ca'-100 g-' (Goff and Hill 1992), some of which is free and unbo-und to casein, and may increase internal Ca2+ directly and thus induce capacitation (Courtens and Paquignon 1985;Courtens et al 1989), membrane rearrangement and destabilization. Over time in Ca'*-free medium, intracellular Ca2+ increased at a low rate in fresh spermatozoa, however, this change was not significantly diffelent from that of cryopreserved cells.…”

Effect of the EGTA (Ethylene Glycol Tetraacetic Acid) Supplementation in the Freezing Extender on Quality of Cryopreserved Bull Sperm

“…This ion concentration increase is due to membrane rearrangements and consequent lipid packing faults [29], which can cause a loss of the effectiveness of the . This redistribution causes some cations to be unbalanced, increasing the amount of some of them in the intracellular sperm and others in the external environment [30][31][32]. These unbalanced cations were negatively correlated with fertility, contributing to high percentage of the variation in the fertility of cryopreserved sperm [33,34].…”