Impact of absolute food deprivation on the reproductive system in male goldfish exposed to sex steroids.

There is a link between metabolism and reproduction as metabolic hormones affect hypothalamus-pituitary-testis (HPT) hormonal functions and vice versa. The aim of the present study was to investigate the effects of negative energy balance on the reproductive system in male goldfish exposed to testosterone (T) and 17ß-estradiol (E2). Following 7 days of food deprivation (FD), ANOVA models showed significant FD × sex steroid interactions on sperm quality and circulating sex steroid levels. When FD effects were investigated, 11-ketotestosterone (11-KT) level and sperm motility and velocity decreased in food-deprived goldfish in the control group. In E2-exposed goldfish, FD decreased sperm production in addition to sperm motility and velocity that coincided with an elevation of circulating E2 level. However, FD did not significantly impact sex steroids and sperm quality in T-exposed goldfish. ANOVA models showed non-significant FD × sex steroid interactions for HSI, GSI, circulating luteinizing hormone (Lh) level, and metabolic (preproghrelin, goat and nucb2) and reproductive (kiss1, gpr54 and gnrh3) mRNAs. Furthermore, results showed that FD decreased HSI, and increased Lh levels and testicular preproghrelin and goat mRNAs, while sex steroids increased mid-brain nucb2, kiss1 and gpr54 mRNAs. Together, our results suggest that FD-induced inhibition of androgenesis resulted in diminished sperm quality associated with activation of the testicular ghrelinergic system, and negative feedback of 11-KT increased Lh level. The FD-induced testicular metabolic and hormonal system was impacted in goldfish exposed to sex steroids. However, the negative effects of FD on sperm quality were accelerated in E2-exposed goldfish due to estrogenic activity. This study provides novel information to better understand metabolic-associated reproductive disorders in fish.

Effect of Metformin on Sertoli Cell Fatty Acid Metabolism and Blood-Testis Barrier Formation.

Sertoli cells (SCs) are essential to maintaining germ cell development. Metformin, the main pharmacologic treatment for pediatric type 2 diabetes, is administered to children during SC maturation. The present study aimed to analyze whether metformin affects SC energy metabolism and blood-testis barrier (BTB) integrity. Primary SC cultures were used for the in vitro studies. In vivo effects were studied in Sprague-Dawley rats treated with 200 mg/kg metformin from Pnd14 to Pnd30. Metformin decreased fatty acid oxidation and increased 3-hydroxybutyrate production in vitro. Moreover, it decreased the transepithelial electrical resistance across the monolayer and induced ZO-1 redistribution, suggesting an alteration of cell junctions. In vivo, a mild but significant increase in BTB permeability and ZO-1 expression was observed in the metformin group, without changes in testicular histology and meiosis progression. Additionally, adult rats that received metformin treatment during the juvenile period showed no alteration in BTB permeability or daily sperm production. In conclusion, metformin exposure may affect BTB permeability in juvenile rats, but this seems not to influence spermatogenesis progression. Considering the results obtained in adult animals, it is possible to speculate that metformin treatment during the juvenile period does not affect testicular function in adulthood.

Reproductive physiology of the boar: What defines the potential fertility of an ejaculate?

Despite decades of research and handling of semen for use in artificial insemination (AI) and other assisted reproductive technologies, 5-10% of selected boar sires are still considered sub-fertile, escaping current assessment methods for sperm quality and resilience to preservation. As end-product, the ejaculate (emitted spermatozoa sequentially exposed to the composite seminal plasma, the SP) ought to define the homeostasis of the testes, the epididymis, and the accessory sexual glands. Yet, linking findings in the ejaculate to sperm production biology and fertility is suboptimal. The present essay critically reviews how the ejaculate of a fertile boar can help us to diagnose both reproductive health and resilience to semen handling, focusing on methods -available and under development- to identify suitable biomarkers for cryotolerance and fertility. Bulk SP, semen proteins and microRNAs (miRNAs) have, albeit linked to sperm function and fertility after AI, failed to enhance reproductive outcomes at commercial level, perhaps for just being components of a complex functional pathway. Hence, focus is now on the interaction sperm-SP, comparing in vivo with ex vivo, and regarding nano-sized lipid bilayer seminal extracellular vesicles (sEVs) as priority. sEVs transport fragile molecules (lipids, proteins, nucleic acids) which, shielded from degradation, mediate cell-to-cell communication with spermatozoa and the female internal genital tract. Such interaction modulates essential reproductive processes, from sperm homeostasis to immunological female tolerance. sEVs can be harvested, characterized, stored, and manipulated, e.g. can be used for andrological diagnosis, selection of breeders, and alternatively be used as additives to improve cryosurvival and fertility.

In vivo and in vitro sperm production: an overview of the challenges and advances in male fertility restoration.

Male infertility can be caused by genetic anomalies, endocrine disorders, inflammation, and exposure to toxic chemicals or gonadotoxic treatments. Therefore, several recent studies have concentrated on the preservation and restoration of fertility to enhance the quality of life for affected individuals. It is currently recommended to biobank the tissue extracted from testicular biopsies to provide a later source of spermatogonial stem cells (SSCs). Another successful approach has been the in vitro production of haploid male germ cells. The capacity of SSCs to transform into sperm, as in testicular tissue transplantation, SSC therapy, and in vitro or ex vivo spermatogenesis, makes them ideal candidates for in vivo fertility restoration. The transplantation of SSCs or testicular tissue to regenerate spermatogenesis and create embryos has been achieved in nonhuman mammal species. Although the outcomes of human trials have yet to be released, this method may soon be approved for clinical use in humans. Furthermore, regenerative medicine techniques that develop tissue or cells on organic or synthetic scaffolds enriched with bioactive molecules have also gained traction. All of these methods are now in different stages of experimentation and clinical trials. However, thanks to rigorous studies on the safety and effectiveness of SSC-based reproductive treatments, some of these techniques may be clinically available in upcoming decades.

Evaluation of Testicular Volume and Correlation with Sperm Production in Martina Franca Donkeys: A Parameter to Consider When Approving Breeding Jacks.

Good sperm production is a notable requirement for subjects intended for reproduction, particularly in endangered species, and it has been demonstrated that in horse stallions, this is correlated to testicular volume. The present study, which involved Martina Franca jacks, aimed to determine whether, also in this endangered breed, there is a correlation between the total sperm number (TSN) and testicular volume. Testes were measured with both ultrasound and a caliper. Testicular volume was calculated using two different formulas: one representing the volume of an ellipsoid and one developed to describe round-shaped testicles. The average sperm concentration was 380.14 ± 254.58 × 106/mL, while the average TSN was 16.34 ± 7.76 × 109. Our findings evidenced a significant correlation (r > 0.75; p < 0.05) only between sperm production and the volume calculated with the formula V (cm3) = 33.57 × H - 56.57 for round-shaped testes. Moreover, significance was evidenced only for data obtained with ultrasound (VTs-us 315.03 ± 25.83 cm3) but not with caliper. In conclusion, testicular volume can be suggestive of good fertility in Martina Franca jacks; thus, this parameter could be considered when selecting breeding animals.

Male gonad-enriched microRNAs function to control sperm production in C. elegans.

Germ cell development and gamete production in animals require small RNA pathways. While studies indicate that microRNAs (miRNAs) are necessary for normal sperm production and function, the specific roles for individual miRNAs are largely unknown. Here, we use small RNA sequencing of dissected gonads and functional analysis of new loss of function alleles to identify functions for miRNAs in the control of fecundity and sperm production in Caenorhabditis elegans males and hermaphrodites. We describe a set of 29 male gonad-enriched miRNAs and identify a set of 3 individual miRNAs (mir-58.1, mir-83, and mir-235) and a miRNA cluster (mir-4807-4810.1) that are required for optimal sperm production at 20°C and 5 additional miRNAs (mir-49, mir-57, mir-261, and mir-357/358) that are required for sperm production at 25°C. We observed defects in meiotic progression in mir-58.1, mir-83, mir-235, and mir-4807-4810.1 mutants that may contribute to the reduced number of sperm. Further, analysis of multiple mutants of these miRNAs suggested complex genetic interactions between these miRNAs for sperm production. This study provides insights on the regulatory roles of miRNAs that promote optimal sperm production and fecundity in males and hermaphrodites.

Sperm competition increases sperm production and quality in Cataglyphis desert ants.

Sperm competition is a pervasive evolutionary force that shapes sperm traits to maximize fertilization success. Indeed, it has been shown to increase sperm production in both vertebrates and invertebrates. However, sperm production is energetically costly, which may result in trade-offs among sperm traits. In eusocial hymenopterans, such as ants, mating dynamics impose unique selective pressures on ejaculate. Males are sperm limited: they enter adulthood with a fixed amount of sperm that will not be renewed. We explored whether sperm competition intensity was associated with sperm quantity and quality (i.e. sperm viability and DNA fragmentation) in nine Cataglyphis desert ants. Our results provide phylogenetically robust evidence that sperm competition is positively correlated with sperm production and sperm viability. However, it was unrelated to sperm DNA integrity, indicating the absence of a trade-off involving this trait. These findings underscore that sperm competition may strongly mould sperm traits and drive reproductive performance in eusocial Hymenoptera.

Associations between insulin-like factor 3, scrotal circumference and semen characteristics in young Norwegian Red bulls.

With the integration of genomic selection in the cattle artificial insemination (AI) industry, bulls are selected for their semen production capacity and fertility at a younger age than previously. Norwegian Red bull calves selected as candidates to become future AI bulls based on their genomic breeding value are kept in a performance testing station from around the age of 3-12 months, allowing for sample collection and analysis of different parameters during their pre- and peripubertal period. Insulin-like factor 3 (INSL3) is a small peptide hormone specifically secreted by the mature Leydig cells of the testes. In the foetus, it induces the first phase of testicular descent and is considered to reflect Leydig cell development during puberty; it could therefore be an interesting early indicator of future semen production capacity. The main objective of our study was to evaluate the relationship between INSL3, scrotal circumference (SC), and semen characteristics. This is the first time INSL3 was measured in the Norwegian Red population. We collected blood samples for analysis of INSL3 from 142 Norwegian Red bulls at the performance testing station and measured their SC on the same day. Altogether, measurements were made at four time points: upon arrival at the performance testing station (quarantine (Q): 2-5 months) and later at approximately 6, 9 and 12 months of age. Information on season and place of birth were made available from the database of the breeding company Geno, together with data on semen characteristics from the test station and the AI station. The median SCs for age groups Q, 6, 9, and 12 were 15, 21.5, 29, and 34 cm, respectively. INSL3 was shown to be positively correlated with SC (R = 0.4) but not with any of the semen characteristics. Similarly, we found no correlation between SC and sperm characteristics from data on ejaculates analysed at the performance testing station and AI station. The mean sperm volume for the 31 selected bulls with at least 10 ejaculates produced in the AI station increased from 2.3 ml at the performance testing station to 6.4 ml at the AI station. The corresponding increase in mean sperm concentration was from 497 million/ml to 1 049 million/ml. We conclude that INSL3 exhibits high inter-individual variability in the Norwegian Red bull population, which cannot be explained by the parameters measured in this study. At present, INSL3 cannot be used as a biomarker of sperm production in this breed.

Juvenile socio-sexual experience determines lifetime sperm expenditure and adult survival in a polygamous moth, Ephestia kuehniella.

Male animals often adjust their sperm investment in response to sperm competition environment. To date, only a few studies have investigated how juvenile sociosexual settings affect sperm production before adulthood and sperm allocation during the first mating. Yet, it is unclear whether juvenile sociosexual experience (1) determines lifetime sperm production and allocation in any animal species; (2) alters the eupyrene : apyrene sperm ratio in lifetime ejaculates of any lepidopteran insects, and (3) influences lifetime ejaculation patterns, number of matings and adult longevity. Here we used a polygamous moth, Ephestia kuehniella, to address these questions. Upon male adult emergence from juveniles reared at different density and sex ratio, we paired each male with a virgin female daily until his death. We dissected each mated female to count the sperm transferred and recorded male longevity and lifetime number of matings. We demonstrate for the first time that males ejaculated significantly more eupyrenes and apyrenes in their lifetime after their young were exposed to juvenile rivals. Adult moths continued to produce eupyrene sperm, contradicting the previous predictions for lepidopterans. The eupyrene : apyrene ratio in the lifetime ejaculates remained unchanged in all treatments, suggesting that the sperm ratio is critical for reproductive success. Male juvenile exposure to other juveniles regardless of sex ratio caused significantly shorter adult longevity and faster decline in sperm ejaculation over successive matings. However, males from all treatments achieved similar number of matings in their lifetime. This study provides insight into adaptive resource allocation by males in response to juvenile sociosexual environment.

Bioinspired engineered nickel nanoparticles with multifunctional attributes for reproductive toxicity.

Nickel nanoparticles (Ni-NPs) have potential applications in high-tech sectors such as battery manufacturing, catalysis, nanotube printing and textile. Apart from their increasing utilisation in daily life, there are concerns about their hazardous nature as they are highly penetrable in biological systems. The carcinogenic and mutagenic ability of Ni-NPs is evident but the research gaps are still there concerning the safety evaluation of Ni-NPs regarding male reproductive ability. This controlled randomized research was planned to assess the male reproductive toxicity of Ni-NPs in Sprague Dawley rats. Ni-NPs of spherical shape and mean particle size of 56 nm were used in the study, characterized by SEM, EDS and XRD. The twenty-five healthy rats (200-220 g) were used for toxicity investigation of Ni-NPs and divided into five groups; negative control (0 Ni-NPs), placebo group (0.9% saline) and three Ni-NPs treated groups (@ 15, 30 and 45 mg/kg BW). The results of 14 days of intraperitoneal exposure to Ni-NPs revealed that a higher dose (45 mg/kg BW) of Ni-NPs caused a significant reduction in body weight, serum testosterone, daily sperm production while the testis index and Ni accumulation and histological changes (necrosis in basement membrane and seminiferous tubules, vacuole formation) in testicular tissues increased with increasing dose of Ni-NPs. It can be concluded from the study that Ni-NPs have potential reproductive toxicity. This study provided the baseline data of Ni-NPs toxicity for the male reproductive system and can be applied for risk assessment in Ni-NPs based products.

Decision-support tool for global allocation of dairy sire semen based on regional demand, supply constraints, and genetic profiles.

An artificial insemination (AI) company seeks to allocate semen units globally by balancing perceived demand with uncertain product supply, in what is an arduous subjective process. This study aimed to objectivize this process by providing a user-friendly linear programming model to allocate bulls' semen units to regions for the next trimester sales period based on maximum revenue, and to describe the features and outcomes of this model when applied to a sample bull herd and global demand scenario reflective of a leading AI company. The objective function of maximizing revenue was calculated by summing the product of units allocated by bull and region with purchase prices assigned by bull and region. Constraints considered were regional demand for overall units, regional preferences for specific genetic traits, bulls' production capacity, and percentage of bulls' units allocated to a single region. A sensitivity analysis was performed to identify the effects of variables and constraints on total revenue. Production, sales, and bull demographic data from 2018 to 2021 from a leading AI company were used to establish base values and build a sample herd of 61 bulls and 5 global regions. The case study provided a maximum revenue of $8,287,197 in semen sales per trimester, with 634,700 units allocated. Of the 61 bulls in the case study, 9 were not allocated to any region. The most limiting constraint was regional demand, which resulted in a surplus of 274,564 units not allocated. A sensitivity analysis confirmed this finding, with the largest shadow prices assigned to regional demands, and indicated that a single unit increase in regional demand would add up to $14.84 in total revenue.

Parental High-Fat High-Sugar Diet Intake Programming Inflammatory and Oxidative Parameters of Reproductive Health in Male Offspring.

Parental nutrition can impact the health of future generations, programming the offspring for the development of diseases. The developing germ cells of the offspring could be damaged by the maternal or the paternal environment. The germ cells in development and their function could be affected by nutritional adversity and therefore, harm the health of subsequent generations. The paternal or maternal intake of high-fat diets has been shown to affect the reproductive health of male offspring, leading to imbalance in hypothalamic-pituitary-gonadal axis, testicular oxidative stress, low testosterone production, and changes in sperm count, viability, motility, and morphology. There is a need for studies that address the combined effects of diets with a high-fat and high-sugar (H) content by both progenitors on male reproduction. In this context, our study evaluated epigenetic parameters and the inflammatory response that could be associated to oxidative stress in testis and epididymis of adult offspring. 90 days-old male rats were divided according to the combination of the parental diet: CD (control paternal and maternal diet), HP (H paternal diet and control maternal diet), HM (H maternal diet and control paternal diet) and HPM (H paternal and maternal diet).We evaluated serum levels of testosterone and FSH; testicular gene expression of steroidogenic enzymes Star and Hsd17b3 and epigenetic markers Dnmt1, Dnmt3a, Dnmt3b, and Mecp2; testicular and epididymal levels of TNF-α, IL-6, IL-10, and IL-1ß; testicular and epididymal activity of SOD, CAT, and GST; the oxidative markers MDA and CP; the daily sperm production, sperm transit time, and sperm morphology. Testicular epigenetic parameter, inflammatory response, oxidative balance, and daily sperm production of the offspring were affected by the maternal diet; paternal diet influenced serum testosterone levels, and lower daily sperm production was exacerbated by the interaction effect of both parental intake of high-fat high-sugar diet in the testis. There was isolated maternal and paternal effect in the antioxidant enzyme activity in the cauda epididymis, and an interaction effect of both parents in protein oxidative marker. Maternal effect could also be observed in cytokine production of cauda epididymis, and no morphological effects were observed in the sperm. The potential programming effects of isolated or combined intake of a high-fat high-sugar diet by the progenitors could be observed at a molecular level in the reproductive health of male offspring in early adulthood.

The most important medicinal plants affecting sperm and testosterone production: a systematic review.

OBJECTIVE: Infertility, defined as the inability to conceive after one year of intercourse without the use of contraception, affects 15% of couples. Many factors, such as genitourinary tract infections, endocrine disorders, immunological factors and drug-related injuries, affect the male reproductive system and cause infertility. Due to men's fear of infertility, it is very important to pay attention to medicinal plants that are effective in male fertility. Therefore, the aim of this study was to evaluate the medicinal plants that affect sperm and testosterone production in men. METHODS: In this review, we used the following search terms, consisting of herbal medicine, traditional medicine, traditional therapies, sperm, testosterone, testicles and Iran were used to retrieve the relevant articles published in the journals indexed in the Information Sciences Institute, Science Direct, PubMed, Scopus, PubMed Central and Scientific Information Databases. We searched and used papers published between 2000 and 2020. Then, we analyzed the eligible papers. We collected and analyzed 35 papers from the databases. We selected only the articles about herbs that affect sperm and testosterone production. RESULTS: Based on the results, herbs Apium graveolens, Cinnamomum camphora, Cornus mas, Satureja khuzestanica, Withania somnifera, Fumaria parviflora, zingiber officinale, cinnamomum zeylanicum and Phoenix dactylifera are used in the male reproductive system. CONCLUSIONS: Plants can probably be useful in increasing fertility due to their antioxidant power and low side effects.

Larval social cues influence testicular investment in an insect.

Socio-sexual environment can have critical impacts on reproduction and survival of animals. Consequently, they need to prepare themselves by allocating more resources to competitive traits that give them advantages in the particular social setting they have been perceiving. Evidence shows that a male usually raises his investment in sperm after he detects the current or future increase of sperm competition because relative sperm numbers can determine his paternity share. This leads to the wide use of testis size as an index of the sperm competition level, yet testis size does not always reflect sperm production. To date, it is not clear whether male animals fine-tune their resource allocation to sperm production and other traits as a response to social cues during their growth and development. Using a polygamous insect Ephestia kuehniella, we tested whether and how larval social environment affected sperm production, testis size, and body weight. We exposed the male larvae to different juvenile socio-sexual cues and measured these traits. We demonstrate that regardless of sex ratio, group-reared males produced more eupyrenes (fertile and nucleate sperm) but smaller testes than singly reared ones, and that body weight and apyrene (infertile and anucleate sperm) numbers remained the same across treatments. We conclude that the presence of larval social, but not sexual cues is responsible for the increase of eupyrene production and decrease of testis size. We suggest that male larvae increase investment in fertile sperm cells and reduce investment in other testicular tissues in the presence of conspecific juvenile cues.

The effect of melatonin on testis histological changes and spermatogenesis indexes in mice following treatment with dexamethasone.

Dexamethasone is a common medicine that is capable of causing malformation in the male reproductive system. The aim of this study was to investigate the effect of melatonin on testis histological changes and Spermatogenesis indexes in adult mice following treatment with dexamethasone. Adult male NMRI mice were divided randomly into four groups: control, dexamethasone (i.p injections, 7 mg/kg/day), dexamethasone + melatonin and melatonin (i.p injections, 20 mg/kg/day). After 7 days of treatment, the right testes were studied stereologically and the left testes were used to measure the daily sperm production (DSP). The serum levels of malondialdehyde (MDA), testosterone and total antioxidant capacity (TAC) were also measured. The left caudal epididymis was used to analyze sperm parameters. Data were analyzed using one way ANOVA and means were considered significantly different at p < 0.05. A significant decrease in the testis volume, seminiferous tubules volume, the number of spermatocytes, round and long spermatids, Spermatogenesis indexes, sperm parameters such as motility, count, viability, tail length and DSP, serum testosterone level, TAC and the body weight was found in the dexamethasone group compared to the control. Meanwhile a significant swelling of the interstitial tissue and a significant increase in the MDA level was found in the dexamethasone group compared to the control. The above parameters reached the control level in the dexamethasone + melatonin group. Melatonin can compensate for the adverse effects of dexamethasone on sperm parameters and the histology of the seminiferous tubules in mice.

Filgrastim (r-met-hu G-CSF) enhances the efficiency of spermatogenesis in prepubertal Bos indicus bulls.

This study aimed to test the effects of the drug r-met-hu-G-CSF (filgrastim) on spermatogenic efficiency in prepubertal Brahman bulls. Twelve intact, healthy prepubertal bulls were administered 0, 1 (LD = low dose) or 4 (HD = high dose) µg/Kg r-met-hu-G-CSF (daily for 4 days), and haematological analysis was performed. Bulls were castrated (D0 or D60). BW (body weight) and SC (scrotal circumference) were recorded. Testis weight and volume were taken at castration with samples for testis histology and stereology: germ cell types, spermatids count and DSP (daily sperm production per gram)/g of testicular parenchyma. Testicular weight, volume, BW, SC and gonadosomatic index (GSI) were NS (LD-HD; p > .05). At D0 (age 11 months), the most advanced germ cell types (maGCt) ranged from intermediate spermatogonia to pachytene spermatocytes. After 2 months, control animals had round spermatids as maGCt, LD animals 75% round spermatids and 25% elongated spermatids, and HD animals round spermatids. Spermatids/testis were higher in LD (1.23 ± 0.2 millions) than in controls (0.65 ± 0.1 millions, p < .05). Spermatogenic efficiency (DSP/g) was higher in LD (5.4 ± 0.4 million) than in controls (3.2 ± 0.2 million, p < .01). In conclusion, r-met-hu-G-CSF raises spermatogenic efficiency in prepubertal Brahman bulls.

Effects of gonadotropin-releasing hormone agonist administered in microparticles on sperm quality and quantity, and plasma sex steroid levels in northern pike.

Artificial reproduction of northern pike Esox lucius is impeded by the likelihood of obtaining only a small volume of sperm of inconsistent quality. A controlled-release hormone delivery system has the potential to enhance sperm production while avoiding multiple injections The objective of this study was to investigate the effects of mammalian gonadotropin-releasing hormone agonist (mGnRHa) incorporated into poly(lactic-co-glycolic acid) (PLGA) microparticles on milt production, spermatozoon characteristics, and secretion of 17ß-estradiol (E2), 11-keto testosterone (11-KT), and testosterone in northern pike. Fish were divided into four groups and injected with 2 mg/kg BW carp pituitary extract (CPE), 20 µg/kg BW mGnRHa in PLGA microparticles, or 20 µg/kg BW mGnRHa plus 20 mg/kg BW metoclopramide (MET) in PLGA microparticles (PLGA + MET), along with a control group injected with 1 ml/kg 0.9% NaCl. At 48 h postinjection, the volume of milt produced was significantly greater in groups treated with CPE and PLGA + MET than in other groups. At 96 h postinjection, all hormone-treated groups exhibited significantly higher spermatozoon average velocity than recorded in the control group. Spermatozoon motility was significantly increased (P < 0.05) in the CPE and PLGA groups compared to baseline values. All treated groups showed significantly lower levels of 11-KT after the hormone injection compared to baseline values and to controls. Plasma testosterone levels increased in all hormone-treated groups. The use of PLGA microparticles, with or without metoclopramide, is suitable for use as a carrier of hormone treatments to regulate spermiation in mature northern pike.

Sperm production and seminal analyses in a Neotropical sperm-storing vespertilionid bat yellowish myotis (Myotis levis).

Yellowish myotis is a Neotropical vespertilionid bat that presents a seasonal reproduction. The sperm is produced in the Mature stage, stored in the Regressed stage and released in the Rest stage (mating period). Aiming to understand, for the first time, the relationship between testis and epididymis physiology in yellowish myotis reproduction, the spermatogenesis length, sperm production, and seminal parameters were herein evaluated. Fifty-one adult male bats were captured in Santuário do Caraça, Minas Gerais, Brazil. The gonads were collected in the Maturing and Mature stages for histomorphometric and immunohistochemical analyses, whereas the epididymis was evaluated in all reproductive stages for seminal studies. Our results demonstrated that the yellowish myotis spermatogenic process is fast, lasting 31.70 ± 0.15 days. Despite the low Sertoli cell efficiency (6.60 ± 1.23), the high numbers of Sertoli cells per testis enable an elevated sperm production in the Mature stage. The sperm concentration, vitality, and motility presented the highest values in the Regressed stage; however, in this period, an increased incidence of sperm morphological defects was detected. In the following period (Rest stage), a drastic reduction of defective sperm was observed, suggesting quality control of sperm before the mating period. Furthermore, the epididymis ability to maintain a long-term sperm-storage was observed in 26.7% of the bats in the Maturing stage. In summary, yellowish myotis presented a fast and high sperm production during the Mature stage. These sperms are stored and selected before mating period.

Damage to the Testicular Structure of Rats by Acute Oral Exposure of Cadmium.

Cadmium (Cd) is one of the most important heavy metal toxicants, used throughout the world at the industrial level. It affects humans through environmental and occupational exposure and animals through the environment. The most severe effects of oral exposure to Cd on the male reproductive system, particularly spermatogenesis, have not been discussed. In this study, we observed the damage to the testes and heritable DNA caused by oral exposure to Cd. Adult male Sprague-Dawley rats were divided into four groups: a control group and three groups treated with 5, 10, and 15 mg Cd/kg/day for 17 days by oral gavage. Our results revealed that Cd significantly decreases weight gain in 10 and 15 mg/kg groups, whereas the 5 mg/kg groups showed no difference in weight gain. The histopathology showed adverse structural effects on the rat testis by significantly reducing the thickness of the tunica albuginea, the diameter of the tubular lumen, and the interstitial space among seminiferous tubules and increasing the height of the epithelium and the diameter of the seminiferous tubules in Cd treated groups. Comet assay in epididymal sperms demonstrated a significant difference in the lengths of the head and comet in all the 3 Cd treated groups, indicating damage in heritable DNA, although variations in daily sperm production were not significant. Only a slight decrease in sperm count was reported in Cd-treated groups as compared to the control group, whereas the tail length, percentage of DNA in head, and tail showed no significant difference in control and all the experimental groups. Overall, our findings indicate that Cd toxicity must be controlled using natural sources, such as herbal medicine or bioremediation, with non-edible plants, because it could considerably affect heritable DNA and induce damage to the reproductive system.

Green Tea Infusion Ameliorates Histological Damages in Testis and Epididymis of Diabetic Rats.

Green tea is a popular drink used for therapeutic purposes to mitigate the consequences of diabetes. In this study, we aimed at evaluating the potential of green tea infusion to ameliorate structural and enzymatic damages caused by hyperglycemia in the testis and epididymis of Wistar rats. For that, nondiabetic and streptozotocin-induced diabetic rats (negative control and diabetes control, respectively) received 0.6 mL of water by gavage. Another set of diabetic animals received 100 mg/kg of green tea infusion diluted in 0.6 mL of water/gavage (diabetes + green tea) daily. After 42 days of treatment, the testes and epididymides were removed and processed for histopathological analysis, micromineral determination, and enzymatic assays. The results showed that treatment with green tea infusion preserved the testicular and epididymal histoarchitecture, improving the seminiferous epithelium and the sperm production previously affected by diabetes. Treatment with green tea reduced tissue damages caused by this metabolic condition. Given the severity of hyperglycemia, there was no efficacy of the green tea infusion in maintaining the testosterone levels, antioxidant enzyme activity, and microminerals content. Thus, our findings indicate a protective effect of this infusion on histological parameters, with possible use as a complementary therapy for diabetes.