Evaluation of effects of Tempol on testicular ischemia/reperfusion injury.

AIM: Tempol, a synthetic antioxidant compound, has received significant attention for its potential therapeutic applications in recent years, especially against ischemia/reperfusion (I/R) injury. The aim of the present research was to assess the protective effects of Tempol on testicular I/R injury caused by testicular torsion and detorsion (T/D) in rats. METHODS: The subjects were divided into five groups: sham, testicular T/D, testicular T/D with Tempol treatment at 50 and 100 mg/kg, and healthy rats treated with Tempol at 100 mg/kg. Testicular torsion was induced by rotating the left testicles for 2 h, followed by detorsion for 24 h. Testicular tissues were evaluated for gene expression, oxidative stress markers, and histopathology, epididymal sperms were stained and analyzed, and blood serum samples were collected to measure the testosterone hormone. RESULTS: The results showed that testicular I/R caused a significant decrease in sperm velocity parameters, viability, and count, as well as an increase in abnormal sperms (p < 0.05). However, treatment with Tempol significantly improved these parameters (p < 0.05). Histopathological analysis revealed severe damage to the testicular tissues, but treatment with Tempol improved the structural integrity of the seminiferous tubules. Testicular I/R also resulted in increased oxidative stress index and decreased testosterone levels significantly (p < 0.05), but Tempol administration mitigated these effects significantly (p < 0.05). Furthermore, the expression of Bax and Bcl2, genes associated with apoptosis, were significantly altered by testicular I/R (p < 0.05), but Tempol prevented these changes significantly (p < 0.05). CONCLUSION: These findings provide strong evidence that Tempol can effectively prevent testicular I/R injury.

Canine and feline foetal fluids: Volume, hormonal and biochemical characterization during pregnancy.

BACKGROUND AND OBJECTIVES: This study aimed to evaluate the volume, the concentration of steroid hormones, and biochemical composition of the foetal fluids at different gestational ages in dogs and cats. METHODS: Following the ovariohysterectomy, the allantoic and amniotic fluid samples were collected from pregnant bitches and queens and were assigned to different groups according to their gestational age. RESULTS: The canine and feline allantoic fluid volume increased during pregnancy, reached its maximum values on days 40-49 and then decreased. The canine and feline amniotic fluid volume increased steadily by the last days of pregnancy. In spite of significant changes of sex hormones in the foetal fluids, their concentration and ratios were not significantly different between male and female fetuses. The canine amniotic cortisol concentration increased until days 40-49 and decreased significantly afterwards. The maximum cortisol concentrations in the feline allantoic and amniotic fluids were observed on days 50-60 and 40-49, respectively. During the canine pregnancy, the concentrations of calcium, phosphorus, chloride, sodium, triglyceride, cholesterol, total protein, albumin and the activities of aminotransferase (AST), alkaline phosphatase (ALP), amylase and gamma-glutamyl transferase (GGT) in the amniotic fluid were higher than the allantoic fluid. The magnesium, potassium, lactate dehydrogenase (LDH) activity, creatine and lipase were higher in the allantoic fluid. In the feline allantoic fluid, potassium, magnesium, phosphorus, creatinine, albumin and glucose concentrations and the activities of creatine kinase (CK), GGT, LDH and lipase were higher. The ALP, AST activities, sodium and calcium concentrations were higher in the amniotic fluid (p < 0.05). CONCLUSION: Volume of foetal fluids was determined in dogs and cats. Concentration of sex hormones did not different between male and female fetuses.

The potential prophylactic and therapeutic impacts of niacin on ischemia/reperfusion injury of testis.

INTRODUCTION: The testicular ischemia-reperfusion (I/R) injury is characterized by the excessive aggregation of un-scavenged reactive oxygen species, leading to the heightened levels of oxidative stress. This phenomenon plays a pivotal role in the pathophysiology of testicular torsion damage. OBJECTIVE: The current study aimed to detect the prophylactic and therapeutic effects of niacin on testicular I/R injury. STUDY DESIGN: Twenty-four healthy adult male Sprague Dawley rats were randomly allocated into three groups as follows: (1) sham group, (2) torsion/detorsion (T/D) group, and (3) treatment group which received 200 mg/kg niacin along with testicular T/D. Torsion/detorsion was induced by 2 h of torsion followed by 10 days of reperfusion period. In the treatment group, niacin was injected 30 min before the reperfusion period intraperitoneally and continued for 10 days by oral gavage. RESULTS: T/D was associated with marked decreases in terms of sperm count, viability, and kinematic parameters versus the sham group (P < 0.05), which niacin significantly reverted the kinematic parameters (P < 0.05). I/R injury caused a significant increase in the number of abnormal epididymal sperms compared to the sham group (P < 0.05). Niacin decreased the epididymal sperm abnormality significantly compared to the T/D group (P < 0.05). Tissue abnormalities in T/D group, such as edema, hyperemia, inflammation, and necrosis were completely visible histopathologically, while the histological changes in the niacin-treated group were better than those in the T/D group. Regarding the pathological parametric evaluations, I/R injury significantly reduced the mean testicular biopsy score (MTBS), germinal epithelial cell thickness (GECT), and mean seminiferous tubular diameter (MSTD), and increased the tubular hypoplasia/atrophy (THA) compared to the sham group (P < 0.05), which niacin treatment significantly improved the MTBS and GECT compared to the T/D group (P < 0.05). T/D significantly increased the oxidative stress index (OSI) and lipid peroxidation (MDA) (P < 0.05). Niacin significantly reduced the OSI and MDA levels compared to the T/D group (P < 0.05). DISCUSSION: The current study found that niacin has preventive/therapeutic effects against the elevation of oxidative stress markers and depletion of antioxidants during I/R injury. Following administration of niacin, a reduction in histologic injury was observed in rats. In our study, we showed the antioxidant properties of niacin and its capacity to protect against I/R damage. CONCLUSION: The findings of the present investigation revealed that niacin, as an antioxidant agent, can suppress the oxidative stress induced by testicular I/R injury, and can be used as a supplementary agent in the treatment of those undergoing testicular torsion surgery.

Effects of extender filtration and egg yolk concentration on canine semen cryopreservation.

The semen cooling and freezing extenders commonly contain the chicken egg yolk (EY) as the main sperm cryoprotectant. Besides its advantages, the EY has large lipoprotein granules that cause several physical and biological interferences. The previous studies have proposed several methods to resolve the problems with the EY-based semen extenders, including mechanical agitation, EY fractionation, replacing the EY with purified EY LDL, and ultrasonication. In the current research, we aimed to evaluate the syringe filtration (220 nm) of an EY-based canine semen freezing extender as a simple and cheap method to remove the EY granules. We also studied the possibility of re-aggregation of EY granules after cooling, freeze/thawing, and lyophilization/rehydration of the filtered extenders. Additionally, we compared the effects of the filtration on lipid profile, turbidity, EY particle size distribution, and osmolality of the EY-based extenders. Next, we examined the effects of filtered extenders containing different levels of EY (5%, 10%, 15%, 20%, and 25%) versus the control extender (20% EY, unfiltered) on post-thaw sperm quality traits. We collected the semen samples from seven clinically healthy mixed-breed adult dogs and pooled them for sperm freezing procedures. Samplings were repeated at least five times, independently. Our results indicated that the syringe filtration could remove the large EY particles and reduce the extender turbidity without affecting the lipid profile of the whole extender solution. The filtered extender supplemented with 25% (v/v) EY led to the best post-thaw canine spermatozoa quality markers. The frozen-thawed spermatozoa evaluations included motility parameters (computer-assisted semen analysis system), membrane and acrosome integrity (hypo-osmotic swelling test, chlortetracycline binding assay), DNA fragmentation (sperm chromatin dispersion assay), membrane lipid peroxidation (MDA levels), apoptosis (Annexin V/propidium iodide assay), and fertility-associated sperm mRNA transcript abundance (protamine 2 and 3). In conclusion, the syringe filtration of the EY-based semen extenders was a simple and cheap method that could effectively remove large EY lipoprotein granules and possibly prevent EY-origin bacterial contamination of the final extender solution. The EY at 25% (v/v) concentration in the filtered extenders resulted in the highest canine spermatozoa cryo-tolerance.

The evaluation of citral effects on experimental unilateral testicular ischemia/reperfusion injury.

This investigation aimed to evaluate the defensive impacts of citral on ischemia/reperfusion (I/R) injury induced by testicular torsion/detorsion (T/D) in rats in an experimental model. The grouping of subjects was as follows: (1) sham, (2) T/D, (3) and (4) T/D plus citral 150 and 300 mg/kg, respectively, and (5) intact (citral 300 mg/kg). T/D was performed by testicular 720° turning for 2 h and then detorsion for 24 h. Blood serum was obtained to assess testosterone and oxidative stress markers, epididymal sperms were collected for sperm staining and sperm analysis, and testicular tissues were examined for histopathology. T/D damage was associated with a remarkable decline in sperm total count, viability, and some velocity parameters in comparison to the sham group (p < 0.05), which could be reversed significantly by citral (p < 0.05). Histopathologically, T/D damage caused severe oedema, haemorrhage, inflammation, and seminiferous tubules disruption, while citral improved significantly the mean seminiferous tubular diameter, Cosentino's score, and Johnsen's score (p < 0.05). I/R injury was associated with significant increased malondialdehyde and oxidative stress index, and also significant reduced total antioxidant capacity and testosterone versus the sham group (p < 0.05), which all were prevented significantly by citral administration (p < 0.05). The outcomes greatly proved that testicular I/R injury could be significantly prevented by citral.

Effects of epididymal sperm recovery methods on fresh and frozen-thawed sperm characteristics in dogs.

The cauda epididymis holds a collectible source of fertile spermatozoa in cases of obstructive azoospermia, sudden death, and after elective or emergency castration. The current study was conducted to compare three different epidydimal sperm collection methods (Percutaneous epididymal sperm aspiration (PESA), microsurgical epididymal sperm aspiration (MESA) and retrograde epididymal wash (EW)) in the dog. Fifteen large-breed adult dogs were applied for comparing the PESA (left testicles) with MESA (right testicles) techniques, while five dogs were used for evaluation of MESA (left testicles) versus EW (right testicles). The recovered sperm cells from MESA and EW were subjected to cryopreservation. Total sperm recovery, level of blood contamination and sperm quality markers (viability, morphology, plasma and acrosome membrane integrity, DNA fragmentation, and metabolic activity) were evaluated for fresh and frozen-thawed spermatozoa. We showed that the collection of epididymal sperm cells through the PESA method resulted in lower total sperm recovery and significantly reduced fresh sperm kinematic and quality measures. While, both MESA and EW procedures resulted in a high number of intact epididymal spermatozoa with appropriate cryo-tolerance potential. In conclusion, EW and MESA methods provide high-quality epidydimal spermatozoa with high cryopreservation potential in domestic dogs.

Supplementation of melatonin to cooling and freezing extenders improves canine spermatozoa quality measures.

BACKGROUND: Sperm freezing and cold storage are the two most common assisted reproductive technologies in the canine breeding industry. The freeze-thawing process causes significant detrimental changes in both sperm cell structure and function. Previous research has confirmed that excessive accumulation of un-scavenged free radicals (oxidative stress) plays an important role in the cryopreservation-induced damage to sperm cells. Also, the gradual accumulation of the free radicals during cold storage leads to a decline in the sperm quality markers. Melatonin is an endogenous neurohormone synthesized from tryptophan amino acid by pineal glands. Besides its several well-known physiologic roles, melatonin has a significant antioxidant potential through direct free radical scavenging properties. Therefore, the current study was designed to evaluate the potential in vitro protective properties of melatonin (0.5, 1, and 2 mM) on canine sperm cells after freezing or during long-term cold storage (9 days, 5 °C) on most important sperm in vitro fertility markers. RESULTS: Melatonin at 0.5, 1- or 2-mM concentrations could preserve significantly higher sperm total motility after 4 days of cold storage. However, only the 1- and 2 mM melatonin concentrations could result in better TM and PM values after 7 days of cold storage. Furthermore, melatonin supplementation could preserve higher sperm viability and acrosome integrity after 7 days of storage. Also, it could have significant protective effects on the cooled sperm DNA integrity. In the freezing section of the current research, melatonin at either 1- or 2-mM concentrations could not improve the sperm post-thaw TM and PM, whereas they improved sperm DNA integrity. Also, the post-thaw plasma membrane functional integrity and sperm velocity parameters were not affected by the treatment. Although DMSO (Dimethyl Sulfoxide) as the melatonin solvent could reduce the level of sperm lipid peroxidation and even improve the post-thaw sperm DNA integrity compared to the negative control, it reduced the post-thaw sperm progressive motility. However, the negative effects were reversed by concurrent melatonin supplementation at 1- and 2-mM concentrations. CONCLUSION: The addition of 1- or 2-mM melatonin to the canine sperm freezing and cooling media could improve sperm motility, viability, acrosome, and DNA integrity.

Protective effects of crocin on testicular torsion/detorsion in rats.

Oxidative stress, caused by extreme accumulation of un-scavenged reactive oxygen species, plays an integral role in the Ischemia-Reperfusion (I/R) injury to the testicles following testicular torsion. The current research aimed to examine the protective effects of crocin as a natural antioxidant on testicular I/R injury in rats. Animals were divided randomly into five groups (seven each): (1) sham group, (2) torsion/detorsion (T/D) group, (3) intact group with 100 mg/kg crocin, (4) and (5) T/D groups followed by treatment with two different doses of crocin (50 and 100 mg/kg (IP)). I/R injury was induced by 720° clockwise torsion of the left testicles for 2 h. After 24 h of reperfusion, blood samples and epididymal sperms were collected to measure biochemical (GPx, SOD, and MDA), hormonal (testosterone), and sperm parameters (total sperm recovery, motility, viability, and morphology). Moreover, affected testicles were subjected to histopathology examination. I/R injury caused a significant reduction in sperm characteristics (except for morphology) (P < 0.05), which could not be significantly improved by crocin administration at either dose (P > 0.05). Johnsen's testicular score, mean seminiferous tubular diameter, and germinal epithelial cell thickness were significantly decreased in the T/D group compared to the intact and sham groups. However, crocin could significantly improve the histopathological parameters in both treatment groups compared to the T/D group (P < 0.05). T/D reduced SOD and GPx activity and testosterone level significantly (except for GPx) compared to the sham group (P < 0.05). However, crocin administration could significantly reverse them. Also, crocin reduced the amount of MDA significantly in the high-dose treatment group in comparison to T/D group (P < 0.05). The results of the current study revealed that crocin could be a promising agent to protect against I/R injury following surgical correction of the testicular torsion.

Nicotinic Acid (Niacin) Supplementation in Cooling and Freezing Extenders Enhances Stallion Semen Characteristics.

In the present study, we aimed to evaluate the possible protective effects of the nicotinic acid (NA) at three concentrations (10, 20, and 40 mM) on the equine cooled and frozen-thawed spermatozoa quality markers including viability, plasma membrane or acrosome integrity, DNA fragmentation, lipid peroxidation, and total oxidant levels. We also evaluated the effects of NA on preservation of the post-thaw sperm quality after 6 hours of cold storage before freezing. Five stallions were used for semen collections. The current experiment was repeated six times using pooled semen samples from two stallions, each time. We showed that NA at 20 and 40 mM concentrations could significantly improve the stallion sperm quality markers during cold storage. However, the protective effects were not different between 20 mM and 40 mM concentrations in most measures. Nicotinic acid could also improve the post-thaw stallion sperm quality at 10, 20, and 40 mM concentrations. However, the 40 mM concentration showed a negative impact on some post-thaw kinematic sperm parameters. Nicotinic acid at 10 and 20 mM concentrations could preserve the sperm cryo-tolerance to be frozen up to 8 hours after collection without a significant decline in most of the post-thaw sperm quality measures. Nicotinic acid could also decrease the level of the lipid peroxidation and total reactive oxygen/nitrogen species in the cooled and frozen-thawed spermatozoa, in a dose-dependent manner. Therefore, NA at 20 mM concentration could preserve most of the stallion sperm quality measures during cold storage (42 hours, 5°C) and enabled storage of cooled stallion semen for 6 hours before freezing without significant deterioration of the post-thaw sperm quality.

The evaluation of attenuated Neospora caninum by long-term passages on murine macrophage cell line in prevention of vertical transmission in mice.

To date, there is no effective vaccine to prevent abortion or vertical transmission associated with neosporosis in cattle. In the present study, the efficacy of a live experimental vaccine of Neospora caninum attenuated (NCa) by long-term serial passages on a murine macrophage cell line was evaluated in the prevention of vertical transmission and abortion in the mouse model. Forty non-pregnant mice were randomly divided into four equal groups including non-immunized/challenged (injected with PBS); positive control (inoculated with un-attenuated NC-1 tachyzoites); immunized/challenged (inoculated with NCa attenuated strain) and immunized/non-challenged or vaccinated (inoculated with NCa) groups. Following pregnancy synchronization, both the immunized and control mice were challenged with virulent live NC-1 tachyzoites (2.5 × 106) in the mid-pregnancy stage. The number of abortions and post-natal pup mortalities was recorded. Serological, molecular, and histopathologic examinations were employed to evaluate the efficacy of the vaccine and the vertical transmission rates. Results indicated that the live attenuated N. caninum strain (NCa) could significantly reduce the risk of abnormal parturitions and fetal mortality in the vaccinated group (20 %) compared to the non-immunized/challenged group (80 %). Also, the NCa strain reduced the lesion score in the brain of the offspring (0.3 vs 1.9) compared to the non-immunized/challenged group (P < 0.05). The molecular assay showed a decrease in the parasite DNA detection rates from 83 % and 77 % in the non-immunized/challenged group to 27 % and 0 % in the vaccine group in the brain and liver tissues, respectively. While in the immunized/non-challenged group no parasite DNA was detected in the brain tissue samples of the pups. Serological analyses showed that NCa strain was able to stimulate the humoral immunity and create effective protection against neosporosis with a moderate systemic IFN-γ response. In conclusion, the NCa strain could significantly (P < 0.05) reduce the risk of vertical transmission and proved to be a safe vaccine while conferring significant levels of protection in the laboratory mice.

Molecular Differentiation of Fasciola Species and Characterization of Genetic Diversity of F. gigantica Using NADH Dehydrogenase I (ND1) Gene in the Endemic Areas of Iran.

BACKGROUND: Fasciola hepatica and F. gigantica are the causative agents of fasciolosis in domestic animals and humans. Based on the morphometric criteria, differential diagnosis between them is problematic. In addition, intermediate forms of Fasciola have been found in Iran, which makes the differentiation more difficult. The aim of the present study was to provide molecular evidence for the existence of F. gigantica in Iran using sequencing analysis of ND1 and PCR-RFLP analysis of ITS2 regions and to study the intraspecies variations of F. gigantica based on mitochondrial ND1 gene polymorphism. METHODS: Forty Fasciola spp. samples collected from four distinct provinces (Fars, Khuzestan, Gilan, Khorasan Razavi) in Iran were collected for morphological and molecular characterization. In molecular method, PCR-RFLP analysis of ITS2 using pagI restriction enzyme was used as a screening approach for F. gigantica differentiation. Then mitochondrial DNA sequence variations in the ND1 gene were used for phylogenetic analysis. RESULTS: Based on the morphometric criteria and RFLP analysis, 14 parasitic samples were initially identified to be F. gigantica. Phylogenetic results showed that there are at least 10 different genotypes of F. gigantica in Iran, which are different from those existing in the GenBank. Twenty-six points out of 410 base pairs of sequenced ND1 gene in 10 varieties of F. gigantica were diagnosed to be polymorphic. From 26 points of polymorphism, only eight resulted in the post-translational amino acid changes in ND1 gene product structure. CONCLUSION: Data revealed noticeable genetic diversity (up to 4.63%) between different varieties of F. gigantica in Iran.

Application of polymerase chain reaction for fetal gender determination using cervical mucous secretions in the cow.

In the current study we aimed to use PCR to investigate the presence of fetal DNA in the bovine (Bos taurus) cervical secretions and maternal serum, and to assess the effectiveness of this method in fetal gender determination. Pregnant uteri and pre-slaughter maternal blood samples were collected from 21 Holstein Frisian cows in a local abattoir. Overall, 13 male and 8 female fetuses were included in the study. Cervical mucus was sampled at the laboratory. After DNA extraction, the PCR amplified a 280 bp fragment from the X-chromosome and a 217 bp fragment from the Y-chromosome based on a sex-related polymorphism in the amelogenin locus. The presence of fetal Y-chromosome was confirmed in seven out of 13 cervical mucus samples collected from cows with male fetuses. Overall test sensitivity for correct sex determination based on PCR assay on cervical samples was equal to 71.4 ± 2 %. In contrast, no fetal Y-chromosome DNA was detected in maternal serum samples from cows with male fetuses. This is the first report on validating the presence of fetal DNA material in the bovine cervical mucus and its potential usefulness for fetal sexing. Further investigations are needed to maximize the accuracy and evaluate the practicality of this approach.