Published-Ahead-of-Print February 22, 2008, DOI:10.2164/jandrol.107.003459
Journal of Andrology, Vol. 29, No. 4, July/August 2008
Copyright © American Society of Andrology
DOI: 10.2164/jandrol.107.003459
Effect of the Cryopreservation Process on the Activity and Immunolocalization of Antioxidant Enzymes in Ram Spermatozoa
E. MARTI*,
J. I. MARTI
,
T. MUIñO-BLANCO*,
AND
J. A. CEBRIÁN-PÉREZ*,
From the * Department of Biochemistry and
Molecular and Cell Biology, School of Veterinary Medicine, University of
Zaragoza; and the
Department of Animal
Production, Centro de Investigación y Tecnología Agroalimentaria
(CITA), Zaragoza, Spain.
|
Correspondence to: Dr J. A. Cebrián-Pérez, Departamento de
Bioquímica y Biología Molecular y Celular, Facultad de
Veterinaria, C/ Miguel Servet, 177. 50013 Zaragoza, Spain (e-mail:
pcebrian{at}unizar.es). |
In this study, certain enzymes in ram semen involved in reactive oxygen
species elimination and their changes during the cryopreservation process were
characterized in order to investigate the hypothesis that the antioxidant
defense system is involved in the maintenance of frozen sperm quality.
Glutathione reductase (GR), glutathione peroxidase (GPx), and superoxide
dismutase (SOD) activities were quantified in ram sperm samples subjected to
cooling and freezing/thawing processes. In addition, their distribution on the
sperm surface and the changes due to cryoinjury were determined by indirect
immunofluorescence. SOD showed the highest antioxidant activity, which was
also twice as high in fresh and cooled samples as in frozen/thawed ones.
Enzymatic activity of GPx and GR showed no significant change throughout the
freezing process. Seminal plasma proteins (SPPs) added alone or with other
compounds showed a protective effect and accounted for an increase in the
sperm quality parameters and enzyme activity levels not only in the fresh
sample but also after cooling and freezing/thawing. These antioxidant enzymes
were distributed over several sperm regions, and we were able to define
several subpopulations according to the obtained sperm immunofluorescence
patterns. The sperm membrane distribution of SOD, GPx, and GR changed
considerably during cryopreservation, and the type and percentage of the
immunofluorescence patterns found in fresh samples were severely modified.
This remodeling was strongly affected by the use of different cryoprotectants.
The mixture of SPPs, oleic/linoleic acids, and vitamin E was able to partly
maintain and recover the fresh enzyme distribution, particularly of SOD.
Key words: Reactive oxygen species, glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase
Copyright © 2008 by The American Society of Andrology.