In vitro supplementation of testosterone or prolactin affects spermatozoa freezability in small ruminants

The regulation of prolactin secretion and its targeting function of teleost

Prolactin is involved in regulating various physiological activities of vertebrates and is one of the most momentous pituitary hormones. However, not enough attention is currently paid to prolactin, especially in teleost. This paper aims to gather, organize, and analyze recent studies on the regulation and functions of prolactin. By comparing with other animal groups, it highlights the significant role of prolactin in fish reproduction, immunity, growth, and osmotic pressure regulation, as well as the upstream and downstream factors that may be involved in the regulation of prolactin functions were introduced to provide a theoretical basis for the in-depth study and potential practical application of prolactin.

Effect of Honey, Coenzyme Q10, and β-Carotene/α-Tocopherol as Novel Additives in Rabbit-Sperm Cryopreservation Extender

The effectiveness of rabbit-sperm cryopreservation is still below average compared to other domestic species. After the sperm cryopreservation process, post-thawing parameters like motility and membrane integrity are significantly compromised. The use of new extender constituents is an approach that can be used to improve the effectiveness of cryopreservation. Accordingly, we used honey (1.25, 2.5, 5, and 10%), coenzyme Q10 (100 and 200 μM), and β-carotene/α-tocopherol (500 μM/620 μM and 250 μM/310 μM) as candidate components for rabbit-sperm extenders during cryopreservation. Ejaculates from commercial adult rabbit bucks (n = 5) were cryopreserved using conventional freezing. Several post-thawing sperm parameters were assessed, including total motility, membrane integrity, viability, nuclear membrane integrity, acrosome reaction, and mitochondrial membrane potential and activation. Additionally, we performed hormonal analyses of the seminal plasma. Moreover, we analyzed the post-thawing levels of a molecular marker of sperm quality, proAKAP4, which was used in rabbits for the first time. Our findings showed that the 2.5% honey supplementation increased the post-thawing sperm motility (13.75 ± 3.75%) compared to the greater concentrations employed. However, the post-thawing motility was negatively affected by the coenzyme Q10 (0%, in both groups) but was not affected by the β-carotene/α-tocopherol supplementation (22 ± 18.15%, and 11.67 ± 10.17%). In conclusion, the cryopreservation protocols of this study did not help to maintain the sperm parameters after thawing. Further studies are required to identify novel protocols to mitigate the damage caused to rabbit sperm during cryopreservation.

Therapeutic potential of testosterone on sperm parameters and chromatin status in fresh and thawed normo and asthenozoospermic samples

BACKGROUND

Hormonal changes alter the physiological level of ROS and cause oxidative stress in the cell. As estimated, hormonal deficiencies, environmental and ideological factors make up about 25% of male infertility. Pathogenic reactive oxygen species (ROS) is a chief cause of unexplained infertility. Limited studies exist on the effects of testosterone on human sperm culture. Therefore, in the current study, the effect of different doses of testosterone on sperm parameters and chromatin quality was investigated.

MATERIALS AND METHODS

Semen samples from 15 normospermic and 15 asthenospermic patients were prepared by swim up method, and then were divided into four groups by exposing to different concentrations of testosterone (1, 10, and 100nM) for 45min. Samples without any intervention were considered as control group. All samples were washed twice. Sperm parameters and chromatin protamination were assessed in each group and the remains were frozen. After two weeks, all tests were repeated for sperm thawed. Also, the MSOM technique was used to determine the sperm morphology of class 1.

RESULTS

Although sperm parameters were not show any significant differences in normospermic and asthenospermic samples exposed to different concentrations of testosterone before and after freezing, chromatin protamination was significantly decreased in the normospermic samples exposed to 10nM of testosterone before freezing (p<0.006), as well as 1 and 10nM of testosterone after freezing compared to control samples (p=0.001 and p=0.0009, respectively). Similarly, chromatin protamination in the asthenospermic samples was significantly decreased at concentration of 1nM of testosterone before and after freezing (p=0.0014 and p=0.0004, respectively), and at concentration of 10nM of testosterone before and after freezing (p=0.0009, p=0.0007) compared to control samples.

CONCLUSION

Using a low dose of testosterone in the sperm culture medium, has positive effects on chromatin quality.

Seminal plasma lipid profiles of differential cryotolerance of semen in Mediterranean Buffalo bulls

The cryotolerance of semen obtained from Mediterranean buffalo bulls usually is more likely to deteriorate during the summer. To obtain the optimal sperm for fertility, the physiological status and reproductive performance of Mediterranean buffalo bulls in the summer and spring were first analysed by assessing blood serum and seminal plasma samples; then, the lipid profiles of seminal plasma were investigated by LC-MS/MS. The T, T3 and SOD levels of serum and seminal plasma in the spring were significantly higher than in the summer (p < .05). The results suggest that T3 level is positively correlated with semen cryotolerance; sphingolipids are potential markers for semen cryotolerance of Mediterranean buffalo. To our knowledge, this is the first report of targeted lipidomics in semen cryotolerance.

Influence of Prolactin Secretion Changes on Sperm Head Size and Freezability in Ibex and Mouflon

Aim: This work examined the influence of induced changes in prolactin (PRL) secretion on sperm cryoresistance of ibex and the mouflon. Materials and Methods: PRL secretion was modified in a first experiment by the use of bromocriptine (BCR, dopamine agonist) during the non-breeding season, and in a second experiment by the use of sulpiride (SLP, dopamine D₂-receptor antagonist) during the rutting season. Slow and ultra-rapid freezing protocols were used to cryopreserve sperm samples. Results: BCR decreased blood plasma PRL concentrations, whereas SLP increased them. Cryoresistance ratios (CRs) for curvilinear velocity (VCL), straight-line velocity (VSL), and average path velocity (VAP) in BCR-treated mouflons were lower than in controls using slow-freezing (p < 0.05), while CRs of motility and morphologically normal sperm of BCR-treated mouflons were greater than controls with ultra-rapid freezing (p < 0.05). BCR increased the head sperm dimensions in ibexes (p < 0.001); conversely, BCR decreased the head dimensions in mouflons (p < 0.001). CR-motility, CR-amplitude of lateral head displacement (ALH), CR-viability, and CR-acrosome integrity in SLP-treated mouflons were lower than in controls with slow-freezing (p < 0.01); CR-viability and CR-acrosome were lower than controls with ultra-rapid freezing (p < 0.05). In ibexes, CR-ALH was lower for SLP-treated (p < 0.05). SLP treatment increased head dimensions in ibexes (p < 0.001) but did not affect the sperm head of mouflons. Conclusion: Our findings show that high levels of blood plasma PRL negatively affect the cryoresistance of ibex and mouflon sperm.

Expression of Aquaglyceroporins in Spermatozoa from Wild Ruminants Is Influenced by Photoperiod and Thyroxine Concentrations

This work identified the presence of AQPs in frozen-thawed sperm of wild ruminants and assessed the influence of the interaction between photoperiod and thyroxine on AQP expression, and on testosterone secretion. Thyroxine and melatonin were administered to ibexes. In a second experiment, performed in mouflons, circulating thyroxine was reduced via treatment with propylthiouracil (PTU), and an artificial long day (LD) photoperiod established. In the ibexes, the melatonin treatment increased the blood plasma testosterone concentration, reduced the cryoresistance ratio (CR) for sperm viability and the presence of an intact acrosome, and increased the percentage of sperm with AQP7 in the acrosome and of AQP3 and AQP10 in the midpiece. In the mouflons, neither the PTU treatment, the LD, nor the combination of both affected the CR of any sperm variable. The percentage of sperm with AQP3 increased in the post-acrosome region but decreased in the tail in the LD+PTU group. The percentage of sperm with AQP10 in the principal piece and endpiece was lower in the PTU+LD group than in the control and LD groups. The influence of photoperiod/melatonin on AQP expression might be indirectly exerted through changes in the testosterone concentration, and thus ultimately affect sperm cryoresistance.

The effect of testosterone and antioxidants nanoliposomes on gene expressions and sperm parameters in asthenospermic individuals

BACKGROUND

antioxidants that used for the infertility treatment cannot have their complete effectiveness, because of their instability in the culture medium.

SIGNIFICANCE

one of the most advances, in the drug delivery systems, is nanoliposomes-loaded, as biodegradable and bioavailable carriers. Hormonal and antioxidant agents encapsulating inside the nanoliposomes were used, to increase the effectiveness of antioxidants in the sperm culture medium.

MATERIALS

Semen sample from 15 asthenospermia were divided into 10 equal parts. After preparation, the sperms were incubated with free form of drugs and nanocarriers contained resveratrol, catalase, resveratrol-catalase and testosterone for 45 min. All sperm parameters, sperm DNA and gene expressions were evaluated before and after freezing.

RESULTS

Before freezing, all nanocarriers and free testosterone showed higher sperm motility compared to free drugs (P=.000). Free Testosterone and free resveratrol-catalase had higher DNA damage compared to nanocarriers (P=.000). Before freezing, the blank nanoliposome and testosterone nanoliposomes had the lowest HSP70 gene expression respectively (P = 0.005) (P = 0.001). After freezing, a significant reduction in sperm motility was observed in the free resveratrol-catalase group (P=.003). Also, a significant increase in sperm viability was observed in the free testosterone and nanoliposomes of blank and testosterone (P > 0.05). The least DNA damage was related to catalase nanoliposomes (P=.000). All nanoliposomes, especially catalase, had the highest percentage of class I morphology compared to the control group (P=.000).

CONCLUSIONS

Nanoliposomes could improve the sperm parameters and DNA integrity before and after freezing, by increasing the effectiveness of antioxidants. So, it can be recommended in the ART lab.

Effect of Glutathione on Sperm Quality in Guanzhong Dairy Goat Sperm During Cryopreservation

In the process of cryopreservation of dairy goat semen, it will face many threats such as oxidative damage, which will affect the motility and plasma membrane function of sperm. As an endogenous antioxidant in animals, glutathione (GSH) can significantly improve the quality of thawed sperm when added to the frozen diluent of semen of pigs and cattle. In this study, different concentration gradients of GSH [0 mmol/L (control), 1, 2, 3, 4 mmol/L] were added to the frozen diluent of Guanzhong dairy goat semen. By detecting the sperm motility parameters, acrosome intact rate and plasma membrane intact rate after thawing, the effect of GSH on the cryopreservation of dairy goat semen was explored. Sperm motility parameters were measured with the computer-aided sperm analysis (CASA) system (total power, TM; forward power, PM; linearity, LIN; average path speed, VAP; straight line speed, VSL; curve speed, VCL; beat cross frequency, BCF). The sperm acrosome integrity rate after thawing was detected by a specific fluorescent probe (isothiocyanate-labeled peanut agglutinin, FITC-PNA), and the sperm plasma membrane integrity rate after thawing was detected by the hypotonic sperm swelling (HOST) method. Reactive oxygen species (ROS) kit, malondialdehyde (MDA) kit, superoxide dismutase (SOD) kit, glutathione peroxidase (GSH-PX) kit were used to detect various antioxidant indicators of thawed sperm. in vitro fertilization experiment was used to verify the effect of adding glutathione on sperm fertilization and embryo development. The results showed that when the concentration of glutathione was 2 mmol/l, the sperm viability, plasma membrane intact rate, and acrosome intact rate were the highest after thawing, reaching 62.14, 37.62, and 70.87% respectively, and they were all significantly higher. In terms of antioxidant indexes; the values of SOD and GSH-PX were 212.60 U/ml and 125.04 U/L, respectively, which were significantly higher than those of the control group; The values of ROS and MDA were 363.05 U/ml and 7.02 nmol/L, respectively, which were significantly lower than the control group. The addition of 2 mmol/L glutathione significantly improves the fertilization ability of sperm. In short, adding 2 mmol/l glutathione to the semen diluent can improve the quality of frozen Guanzhong dairy goat sperm.