Biochemical and physiological changes in bovine sperm during extended incubation under aerobic and anaerobic conditions
type: CreativeWork
description: There are two main systems for storing diluted bovine semen for artificial insemination. It is either cryo-preserved in liquid nitrogen or held in liquid form at ambient temperature. During storage at ambient temperature, reactive oxygen species generated in the presence of oxygen are a major cause of cellular damage eventuating in the loss of fertility of sperm cells. This has been known for many years and current production systems for storage of semen in the liquid state attempt to minimise oxidative stress. This is achieved by reducing oxygen tension in the diluent through nitrogen gassing and by removal of hydrogen peroxide by catalase. However, the complete elimination of oxidative damage is not achieved because of diffusion of oxygen back into the diluent during re-dilution and packaging of individual insemination doses. The present study was conducted to broaden the understanding of the biochemical mechanisms contributing to the drop in fertility during in vitro storage of sperm at ambient temperature, in relation to the oxidative state of the storage medium. To this aim, the survey was undertaken to determine the biochemical and physiological changes occurring in sperm during extended incubations (storage) under conditions of either complete exclusion of oxygen from the diluent, reduced oxygen tension, normal atmospheric conditions or elevated exposure to reactive oxygen species. Velocities of bovine sperm in a medium containing glucose were found to be similar under fully anaerobic and aerobic conditions. Sperm were not able to sustain motility under anaerobic conditions when glycolysis was inhibited, but regained motility when re-aerated. This demonstrated that immobilisation when glycolysis was inhibited was due to lack of oxygen and that conditions under which motility was analysed were truly anaerobic. Sperm motility parameters were not significantly different in the presence and absence of 4 μmol/1 antimycin A and 4 μmol/1 rotenone when glucose was pr…
abstract: There are two main systems for storing diluted bovine semen for artificial insemination. It is either cryo-preserved in liquid nitrogen or held in liquid form at ambient temperature. During storage at ambient temperature, reactive oxygen species generated in the presence of oxygen are a major cause of cellular damage eventuating in the loss of fertility of sperm cells. This has been known for many years and current production systems for storage of semen in the liquid state attempt to minimise oxidative stress. This is achieved by reducing oxygen tension in the diluent through nitrogen gassing and by removal of hydrogen peroxide by catalase. However, the complete elimination of oxidative damage is not achieved because of diffusion of oxygen back into the diluent during re-dilution and packaging of individual insemination doses. The present study was conducted to broaden the understanding of the biochemical mechanisms contributing to the drop in fertility during in vitro storage of sperm at ambient temperature, in relation to the oxidative state of the storage medium. To this aim, the survey was undertaken to determine the biochemical and physiological changes occurring in sperm during extended incubations (storage) under conditions of either complete exclusion of oxygen from the diluent, reduced oxygen tension, normal atmospheric conditions or elevated exposure to reactive oxygen species. Velocities of bovine sperm in a medium containing glucose were found to be similar under fully anaerobic and aerobic conditions. Sperm were not able to sustain motility under anaerobic conditions when glycolysis was inhibited, but regained motility when re-aerated. This demonstrated that immobilisation when glycolysis was inhibited was due to lack of oxygen and that conditions under which motility was analysed were truly anaerobic. Sperm motility parameters were not significantly different in the presence and absence of 4 μmol/1 antimycin A and 4 μmol/1 rotenone when glucose was pr…
author: Krzyzosiak, J.
license: https://researchcommons.waikato.ac.nz/bitstreams/defe1840-36aa-4517-9d34-2e39ad9e33ce/download
date published: 2000
date modified: 2026-07-24T05:57:30Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Waikato