The antioxidant effects of soybean lecithin- or low-density lipoprotein-based extenders for the cryopreservation of brown-bear (Ursus arctos) spermatozoa
M. Alvarez-Rodríguez A B , M. Alvarez A B , L. Anel-López A B , C. Martínez-Rodríguez A D , F. Martínez-Pastor A D , S. Borragan C , L. Anel A B and P. de Paz A D E
+ Author Affiliations
- Author Affiliations
A ITRA-ULE, INDEGSAL, University of León, 24071 León, Spain.
B Animal Reproduction and Obstetrics, University of León, 24071 León, Spain.
C Cabárceno Park, 39627 Cabárceno, Cantabria, Spain.
D Molecular Biology (Cell Biology), University of León, Campus de Vegazana, 24071 León Spain.
E Corresponding author. Email: ppazc@unileon.es
Reproduction, Fertility and Development 25(8) 1185-1193 https://doi.org/10.1071/RD12181
Submitted: 8 June 2012 Accepted: 16 November 2012 Published: 14 January 2013
Abstract
Egg yolk low-density lipoproteins (LDL) and soybean lecithin were evaluated as replacements for egg yolk in extenders used for the cryopreservation of brown-bear spermatozoa. The motility, viability and acrosomal status of post-thawed spermatozoa were analysed, and an egg-yolk extender was used as a control. The total antioxidant capacity of these extenders was tested. Soybean lecithin showed an effect that was dependent on the soybean concentration (2%, 3.5% and 5%) and source (Type A: 24% l-α-phosphatidylcholine, and Type B: 14–23% l-α-phosphatidylcholine). Only semen cryopreserved with 5% Type A soybean exhibited a sperm motility similar to that of semen cryopreserved in egg-yolk-based extender after thawing, although the sperm viability and acrosome status were not as high. Semen frozen in an extender containing LDL (10–15%) exhibited improved sperm viability in comparison with the control, but sperm motility was lower. The LDL-based extender exhibited a higher anti-oxidant activity than the egg-yolk extender and soy lecithin-based extenders. The extenders with higher anti-oxidant activity showed improvements in frozen sperm viability but lower semen motility. These results indicate that soybean lecithin did not have the same protective effect as egg yolk during the freezing of brown-bear spermatozoa but suggest that LDL (10–15%) could be a useful substitute for egg yolk in these extenders.
Additional keywords: anti-oxidant activity, egg-yolk LDL, sperm motility, viability.
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