Glutathione supplementation to semen extender improves the quality of frozen-thawed canine spermatozoa for transcervical insemination

Abstract

The present study was conducted to evaluate whether supplementation of semen extender with glutathione (GSH) can maintain the quality of frozen-thawed canine spermatozoa. Eighteen ejaculates were obtained from 5 dogs and placed in extender (20% egg yolk, Tris, citric acid, lactose, raffinose, antibiotics and 6.5% glycerol) containing 0 (control), 2.5, 5, 7.5 or 10 mM GSH. The samples were cooled to 4 C and then frozen in liquid nitrogen vapor. Motility parameters of the sperm were evaluated at 0, 1, 2, 3, 4, 12 and 24 h after thawing. Sperm motility was higher in the 5 mM GSH group than in the control or 2.5 and 10 mM GSH groups; this effect was observed at 1 to 24 h after thawing (P < 0.05). The 5 mM GSH group had a higher sperm viability index at 12 and 24 h after thawing compared with the other groups (P < 0.05). Acrosome integrity, evaluated at 4 h after thawing, was greater in two of the GSH-treated groups (5 and 10 mM) compared with the control. Lipid peroxidation (LP) levels immediately after thawing were lower in the 5 and 10 mM GSH groups compared with the control, while those at 12 h after thawing did not differ significantly. Frozen-thawed semen in the 5 mM GSH group was used for transcervical insemination of 4 bitches, resulting in delivery of 5 puppies from 2 bitches. These results indicate that supplementation of semen extender with 5 mM GSH was effective in improving motility, longevity and acrosomal integrity and inhibiting LP levels in post-thaw canine spermatozoa, without any adverse impacts on full-term development after transcervical insemination.

The use of reduced glutathione (GSH) as antioxidant for cryopreserved sperm in dogs

“…only in chilled samples) analyzed by the cytochemical technique of 3.3' diaminobenzidine. These results show that control and GSH in 5mM concentration promotes a better mitochondrial functionality which can reflect in an increased in motility rates and may improve pregnancy, such as previously described (Ogata et al, 2015). Thus, despite our motility results (by CASA) show no changes, this parameter should be better investigated in futures studies.…”

“…GPx; GSH and PHGPx) combined with SOD had an important effect in ROS combat, because this enzymes catalyse the chain reaction in which superoxide anion (O2 -), the first produced ROS, is converted into water (H 2 O 2 ) (Cadenas and Davies, 2000). Moreover, glutathione develops an important function in the preservation of membrane integrity against lipid peroxidation, sperm motility and avoid premature acrosome reaction (Alvarez and Storey, 1989;Rejraji et al, 2002;Gadea et al, 2013). Therefore, antioxidant supplementation (i.e.…”

“…Actually, in humans the supplementation or addition of antioxidant substances presents more promising results when in domestic animals (Kobori et al, 2014;Kedechi et al, 2017). However, Ogata et al (2015) observed that sperm cryopreserved using 5mM of reduced glutathione (GSH) had an increased in motility and higher acrosome integrity. Lucio et al (2016b) in similar study using 10mM of GSH described superior acrosome integrity and positive pregnancies in sperm cryopreserved.…”

Effect of extender supplementation with low-molecular-weight antioxidants on selected quality parameters of cryopreserved canine spermatozoa

“…Innovative methods for the cryopreservation of canine semen facilitate the transfer of desirable genetic material from the most valuable stud dogs, contribute to the preservation of endangered canine breeds, and enhance the utilisation of specific genetic traits in male dogs ( 32 ). Recent research has contributed valuable information about the role of genes encoding behavioural and personality traits in dogs, including assistance dogs ( 22 ).…”

Epigallocatechin-3-gallate added after thawing to frozen dog semen: Effect on sperm parameters and ability to bind to oocytes’ zona pellucida

“…Several substances were used to increase the quality of cryopreserved sperm cells in canine species to mitigate the adverse effect of cryopreservation: ascorbic acid and glutathione, alone or in association, were added to the freezing medium and exerted a positive effect on post thawing sperm longevity and viability [6]. In addition, a more recent study showed positive effects of glutathione on sperm quality and fertility when added to the freezing medium [7]. Vitamin C, N-acetyl-Lcystein, taurine, catalase, vitamin E and vitamin B12 were added to the freezing extender separately [5]; that study demonstrated that antioxidant exerted positive effects on dog semen but the most effective one was catalase.…”