Vincristine-associated total antioxidant and oxidant status of ovaries and in vitro nuclear oocyte maturation in dogs with canine transmissible venereal tumor.

The aim of this study is to evaluate the effects of scheduled vincristine sulfate therapy on canine oocyte quality and nuclear oocyte maturation, associated with total antioxidant and oxidant status of ovaries and Anti-Müllerian Hormone (AMH) concentrations in dogs with Canine Transmissible Venereal Tumor (CTVT). Six bitches suffering from CTVT and six healthy bitches were included in the study. Hemogram was carried out weekly. AMH measurements and ovariohysterectomy operations were performed after the termination of vincristine sulfate therapies. Tissue samples from ovaries were utilized for Malondialdehyde (MDA), reduced Glutathione (GSH), Superoxide Dismutase (SOD), Total Anti-oxidative Status (TAS), Total Oxidative Status (TOS) measurements, and Oxidative Stress Index (OSI) was calculated. Collected oocytes were evaluated for meiotic competence, after In Vitro Maturation (IVM) and parthenogenetic activation. No difference between the two groups was observed in hematologic parameters (P > 0.05). Meiotic stages of Germinal Vesicle Break Down (GVBD), Metaphase I (MI), and Metaphase II (MII) were significantly different between groups (P < 0.05). The number of oocytes reaching MII and meiotic resumption was lower in the CTVT group. Furthermore, AMH concentrations, oxidant parameters (OSI, TOS, and MDA), and antioxidant parameters (GSH, SOD, and TAS) were also statistically different between groups (P < 0.05). The results of this study show that vincristine sulfate application in the treatment of CTVT could alter oxidant/antioxidant status in ovaries. Apart from these, oocyte quality and IVM rates seem to decline related to gonadotoxicity. Moreover, AMH could be an important marker in the evaluation of oocyte qualities in bitches, as it is in women.

Effect of sperm pooling with seminal plasma collected in breeding or nonbreeding season on Saanen goat sperm cryosurvival.

The aim of this study was to determine the effects of both the removal of seminal plasma (SP) and the pre-freezing addition of seminal plasma collected during the breeding or nonbreeding season on goat sperm survival after thawing. Semen samples were pooled. One aliquot of pooled semen was used as a control group. Four aliquots were then centrifuged, and the SP was removed in Group I, pipetted but not removed in Group II, removed and then pooled for animals collected in the breeding season in Group III and removed and pooled for animals collected in the nonbreeding season in Group IV. Group samples were frozen and then were assessed for rates of sperm motility, plasma membrane functional integrity hypo-osmotic swelling test (HOST), defective acrosomes (FITC-PSA), DNA fragmentation (TUNEL) and mitochondrial membrane damage (Rhodamine 123). The results showed that pre-freezing addition of SP collected in breeding season maintained post-thaw sperm characteristics at 0 hr better than SP removal group, but removing seminal plasma showed positive effects on spermatozoa, as incubation time increased to 5 hr. In conclusion, the pre-freezing addition of seminal plasma did not maintain post-thaw goat sperm characteristics as successfully as in the groups with seminal plasma removed after an incubation period.

Effects of different cryoprotective agents on ram sperm morphology and DNAintegrity.

This study investigates the effects of glycerol, 1,2 propanediol, sucrose, and trehalose on post-thaw motility, morphology, and genome integrity of Awassi ram semen. Ejaculates of thick consistency with rapid wave motion (>+++) and >70% initial motility were pooled. Sperm were diluted to a final concentration of 1/5 (semen/extender) in 0% cryoprotectant, 6% glycerol, 6% 1,2 propanediol, 62.5 mM sucrose or 62.5 mM trehalose using a two-step dilution method. The equilibrated semen was frozen in 0.25-ml straws. Semen samples were examined for sperm motility, defective acrosomes (FITC-Pisum sativum agglutinin (FITC PSA)), DNA integrity (acridine orange staining (AO)) and apoptotic activity (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and Caspase-3 activity) at four time points: after dilution with extender A, after cooling to 5 degrees C, after equilibration and post-thaw. Freezing and thawing procedures (cooling at 5 degrees C, dilution, equilibration, and thawing) had negative effects on motility (P<0.001), acrosome integrity (P<0.001), and DNA integrity as determined by AO (P<0.001) and TUNEL (P<0.001) assays. There were positive correlations between sperm with defective acrosomes and apoptotic (AO- and TUNEL-positive) spermatozoa. In contrast, a significant negative correlation was found between sperm motility and defective acrosomes and AO- and TUNEL positivity (P<0.01). The cryopreservation process acts as an apoptotic inducer in ram semen; all cryoprotectants used in the present study allowed apoptosis to some extent, with negative effects on sperm morphology and DNA integrity. The glycerol group performed better than the propanediol, sucrose, trehalose, and control groups in terms of post-thaw sperm motility but not DNA integrity.