Male Reproductive Physiology Research Articles

Impact of Smoking on Reproductive Health: A Systematic Review

Background: Several research endeavours have endeavoured to evaluate the impact of smoking on the physiology of male and female reproduction. Encompassing sperm parameters, male reproductive architecture, and the male hormonal axes. However, the outcomes have been conflicting and ambiguous. Objectives: To investigate the published literature on the effect of smoking on female and male reproductive health. Methods: PubMed, SCOPUS, Web of Science, and Science Direct were systematically searched for relevant literature. Rayyan QRCI was employed throughout this comprehensive process. Results & interpretation: We included thirteen studies with a total of 10092 participants; 4419 (43.8%) were males, and 5673 (56.2%) were females. Smoking is a risk factor in and of itself for male reproductive health. This is more likely to explain smokers' elevated SHBG levels and differential activity of the seminal antioxidant system. These negative effects included abnormal semen motility, volume, count, and morphology. Additionally, smoking had no discernible impact on women's fertility or ovarian reserve, according to this study. More research is needed to determine whether stopping smoking can treat male infertility caused by these substances and to better understand how cigarette smoke affects both female and male fertility.

In vivo dynamic volumetric imaging of mouse testis and epididymis with optical coherence tomography†.

The implementation of live imaging in reproductive research is crucial for studying the physiological dynamics. Sperm transport is a highly dynamic process regulated by tubular contractions and luminal flows within the male reproductive tract. However, due to the lack of imaging techniques to capture these dynamics in vivo, there is little information on the physiological and biomechanical regulation of sperm transport through the male reproductive tract. Here, we present a functional in vivo imaging approach using optical coherence tomography, enabling live, label-free, depth-resolved, three-dimensional, high-resolution visualization of the mouse testis and epididymis. With this approach, we spatiotemporally captured tubular contractility in mouse testis and epididymis, as well as microstructures of these reproductive organs. Our findings demonstrated that the contraction frequency varies significantly depending on the epididymal regions, suggesting the spatial regulation of epididymal contractility. Furthermore, we implemented quantitative measurements of the contraction wave and luminal transport through the epididymal duct, revealing the physiological dynamics within the male reproductive tract. The results show that the contraction wave propagates along the epididymal duct and the wave propagation velocity was estimated in vivo. In conclusion, this is the first study to develop in vivo dynamic volumetric imaging of the male reproductive tract, which allows for quantitative analysis of the dynamics associated with sperm transport. This study sets a platform for various studies investigating normal and abnormal male reproductive physiology as well as the pharmacological and environmental effects on reproductive functions in mouse models, ultimately contributing to a comprehensive understanding of male reproductive disorders.

Recent Progress of In Vitro 3D Culture of Male Germ Stem Cells.

Male germline stem cells (mGSCs), also known as spermatogonial stem cells (SSCs), are the fundamental seed cells of male animal reproductive physiology. However, environmental influences, drugs, and harmful substances often pose challenges to SSCs, such as population reduction and quality decline. With advancements in bioengineering technology and biomaterial technology, an increasing number of novel cell culture methods and techniques have been employed for studying the proliferation and differentiation of SSCs in vitro. This paper provides a review on recent progress in 3D culture techniques for SSCs in vitro; we summarize the microenvironment of SSCs and spermatocyte development, with a focus on scaffold-based culture methods and 3D printing cell culture techniques for SSCs. Additionally, decellularized testicular matrix (DTM) and other biological substrates are utilized through various combinations and approaches to construct an in vitro culture microenvironment suitable for SSC growth. Finally, we present some perspectives on current research trends and potential opportunities within three areas: the 3D printing niche environment, alternative options to DTM utilization, and advancement of the in vitro SSC culture technology system.

SAT020 Is Testosterone The Male Sex Hormone Responsible For Increased Male Mortality In Melanoma? In-vitro Studies On Two Human Melanoma (BLM, 1205Lu) Cell Models

Abstract Disclosure: P. Ramaraj: None. Epidemiological data pointed to increased male mortality in melanoma and clinical studies pointed to better protection of menstruating females in melanoma than post-menopausal women and men of any age. Our in-vitro studies with progesterone (P) on human melanoma (BLM and 1205Lu) cell lines showed a significant decrease in cell growth along with a decrease in the secretion of proinflammatory cytokine IL-8 by these cells. These in-vitro studies correlated with the hormonal data which showed that progesterone levels in menstruating females ranged between 1000 - 1500 ng/dl, compared to post-menopausal women 20 - 100 ng/dl and men 27-90 ng/dl, suggesting low progesterone levels meant no protection in melanoma. This observation prompted us to hypothesize that lack of progesterone in males could be a cause for increased male mortality. This hypothesis also raised the question of the role of male sex hormones (AD-androstenedione and T-testosterone) in increased male mortality. In order to address these questions in-vitro experiments were planned. First, to indirectly induce endogenous IL-8 by pretreating the cells with endothelin and then adding steroid hormones (AD, T, P). Secondly, to add IL-8 directly to the cells and then add steroid hormones. Finally, to suppress endogenous IL-8 with curcumin and then add T to one set of cells and IL-8 + T to another set of cells. For the first experiment, the result was a marginal increase in cell growth (67%) in cells pretreated with endothelin followed by T-treatment compared to straight T-treated cells (60% cell growth) without endothelin pretreatment. For the second experiment, there was a slight increase in cell growth in IL-8-added cells, but it was not statistically significant. For the final experiment, the cells treated with IL-8 + T after curcumin pretreatment showed a partial restoration of cell growth (49%) compared to cells (40% cell growth) treated with plain T after curcumin treatment, suggesting T was not able to control or regulate IL-8 action like progesterone. These in-vitro experiments suggested that in males 2 reasons 1) a deficiency of progesterone and 2) inefficiency of T to control endogenous IL-8 could possibly result in increased IL-8 levels. This increased IL-8 level in males could lead to increased cell growth and metastasis in melanoma leading to death. So, a situation arising out of male reproductive endocrine physiology could probably be responsible for increased male mortality in melanoma. Presentation: Saturday, June 17, 2023

Genotype-by-environment interactions influence the composition of the Drosophila seminal proteome.

Ejaculate proteins are key mediators of post-mating sexual selection and sexual conflict, as they can influence both male fertilization success and female reproductive physiology. However, the extent and sources of genetic variation and condition dependence of the ejaculate proteome are largely unknown. Such knowledge could reveal the targets and mechanisms of post-mating selection and inform about the relative costs and allocation of different ejaculate components, each with its own potential fitness consequences. Here, we used liquid chromatography coupled with tandem mass spectrometry to characterize the whole-ejaculate protein composition across 12 isogenic lines of Drosophila melanogaster that were reared on a high- or low-quality diet. We discovered new proteins in the transferred ejaculate and inferred their origin in the male reproductive system. We further found that the ejaculate composition was mainly determined by genotype identity and genotype-specific responses to larval diet, with no clear overall diet effect. Nutrient restriction increased proteolytic protein activity and shifted the balance between reproductive function and RNA metabolism. Our results open new avenues for exploring the intricate role of genotypes and their environment in shaping ejaculate composition, or for studying the functional dynamics and evolutionary potential of the ejaculate in its multivariate complexity.

Immunoregulatory mechanisms between epithelial clear cells and mononuclear phagocytes in the epididymis.

One of the most intriguing aspects of male reproductive physiology is the ability of the epididymis to prevent the mounting of immune responses against the onslaught of foreign antigens carried by spermatozoa while initiating very efficient immune responses versus stressors. Epithelial clear cells are strategically positioned to work in a concerted manner with region-specific heterogeneous subsets of mononuclear phagocytes to survey the epididymal barrier and regulate the balance between inflammation and immune tolerance in the post-testicular environment. This review aims to describe how clear cells communicate with mononuclear phagocytes to contribute to the unique immune environment in which sperm mature and are stored in the epididymis. A comprehensive systematic review was performed. PubMed was searched for articles specific to clear cells, mononuclear phagocytes, and epididymis. Articles that did not specifically address the target material were excluded. In this review, we discuss the unexpected roles of clear cells, including the transfer of new proteins to spermatozoa via extracellular vesicles and nanotubes as they transit along the epididymal tubule; and we summarize the immune phenotype, morphology, and antigen capturing, processing, and presenting abilities of mononuclear phagocytes. Moreover, we present the current knowledge of immunoregulatory mechanisms by which clear cells and mononuclear phagocytes may contribute to the immune-privileged environment optimal for sperm maturation and storage. Notably, we provide an in-depth characterization of clear cell-mononuclear phagocyte communication networks in the steady-state epididymis and in the presence of injury. This review highlights crucial concepts of mucosal immunology and cellcell interactions, all of which are critical but understudied facets of human male reproductive health.

Diet impacts the reproductive system’s maturation in the male moth Agrotis ipsilon (Noctuidae, Lepidoptera)

In male moth Agrotis ipsilon, sexual maturation occurs between the third and the fifth day of adult life and is characterized by the development of the reproductive organs such as testes and accessory sex glands. Since sexual maturation requires considerable energy investment, we hypothesized that diet would be an essential regulatory factor in this developmental process. Indeed, the links between the male diet and reproductive physiology have not been described as in females. To test the previous hypothesis, we offered male moths diets corresponding to different flower nectars found in nature, and measured morphological and functional changes in the testes and accessory sex glands. In comparison to a diet composed of sucrose only, males fed with a diet composed of diverse sugars, including glucose, supplemented with sodium led to an earlier increase in the length and the protein content of accessory sex glands, as well as a reduction of the testicular volume accompanied by an acceleration of the sperm bundle transfer from the testes to the duplex. These results show that these specific diets accelerate the maturation of the reproductive system in male moth Agrotis ipsilon.

Identification and expression specificity of chemosensory genes in the male reproductive system of Spodoptera exigua

Some chemosensory genes are found to be expressed specifically or highly in the male reproductive system, suggesting their importance in male reproductive physiology. In this paper, we identified chemosensory genes expressed in the male reproductive system of the moth pest Spodoptera exigua by transcriptome and proteome sequencing, and further determined expression patterns of these genes regarding antennae and different tissues of the male reproductive system (testes, vas deferens, seminal vesicles, ejaculatory ducts, male accessory glands) by the real-time quantitative PCR (qPCR). Transcriptome analysis showed that 46 chemosensory genes were expressed in the male reproductive system of S. exigua, including 18 odorant binding proteins (OBPs), 12 chemosensory proteins (CSPs), 10 odorant receptors (ORs) and 6 other chemosensory genes. Further qPCR measurements revealed that 14 chemosensory genes were expressed specifically or highly in the male reproductive tissues, relative to that in male antennae. Of the 14 genes, OBP17, OBP22, OBP27 and GR43 were specifically expressed in the testes; OBP20 was specifically expressed in the vas deferens; and PBP4 was specifically expressed in the male accessory glands. In addition, proteome data of the spermatophore confirmed that at least 4 OBPs and one CSP were transmitted from males to females, suggesting their function in the reproductive physiology of mated females. The results provide insights into the functional diversity of chemosensory genes, and bases for exploring functions of these chemosensory genes in male reproductive physiology.

Impact of environmental variables on some reproductive metrics of white-lipped peccaries (Tayassu pecari) raised in Atlantic Forest of Brazil

Knowledge on male reproductive physiology is essential for the development of effective conservation strategies. This study investigated the influence of environmental variables on certain reproductive metrics in white-lipped peccaries (Tayassu pecari) raised in the Atlantic Forest. After anesthetization, testicular and cauda epididymis biometry were evaluated in nine adult male individuals subjected to electroejaculation. Semen was evaluated for volume, pH, concentration, total number of sperm, sperm morphology, membrane integrity, and kinematic parameters. Concurrently, environmental variables were collected from the day before, for the previous 14 days (estimated for sperm maturation in epididymis), and the period of 51–55 days (corresponding to the spermatogenic cycle) before semen collection. Overall, it was observed that rainfall is the most important environmental variable influencing the reproductive parameters of white-lipped peccaries, being positively correlated with the amplitude of lateral sperm head displacement (ρ = 0.62, P < 0.05) and the appearance of proximal cytoplasmic droplets in sperm (ρ = 0.62, P < 0.05). In addition, the testicular biometry of the species is influenced by the set of environmental variables of air temperature, rainfall, and relative humidity (ρ ≥ 0.60, P < 0.05). On the other hand, epididymal biometric data showed numerous correlations between cauda epididymis metrics and sperm parameters (ρ = 0.68, P < 0.05). This information will be useful to improving conservation strategies for these animals, contributing to their management in captivity and to reintroduction programs, especially in the Atlantic Forest where the species is declining.

Abstract 5287: Is testosterone the male sex hormone responsible for increased male mortality in melanoma? In-vitro studies based on human melanoma (BLM) cell model

Abstract Clinical studies showed that menstruating females were better protected in melanoma than post-menopausal women and men of any age. But, these studies did not correlate with the steroid status of females. Our in-vitro study with progesterone (P), a female sex hormone showed significant inhibition of human melanoma cell growth. A literature survey showed that progesterone levels ranged between 1000-1500 ng/dl in menstruating females compared to post-menopausal women (20-100 ng/dl) and men (27-90 ng/dl), suggesting increased progesterone levels could offer protection to the menstruating females. Moreover, Elisarray showed that progesterone action was mediated by specific suppression of proinflammatory cytokine IL-8. So, it was proposed that a low level of progesterone in males leading to non-suppression of IL-8 in melanoma, could be responsible for increased melanoma cell growth and male mortality. This hypothesis prompted us to check the effect of male sex hormones androstenedione (AD) and testosterone (T) on melanoma cell growth and IL-8 secretion. Both AD and T decreased IL-8 secretion along with a decrease in cell growth. However, when progesterone was added along with androgens, there was a significant decrease in cell growth and in IL-8 secretion. This raised the question of why male mortality was high when androgens also decreased cell growth and IL-8 secretion. In order to address this question, it was decided to induce endogenous IL-8 in melanoma cells by pre-incubating with endothelin (50ng/ml) and then add steroids. AD and P individually decreased IL-8 secretion and in combination significantly decreased IL-8 secretion and cell growth even in endothelin pretreated cells when compared to their respective control cells. But, T was not able to suppress endogenous IL-8 induced by endothelin and in fact, cell growth also was slightly increased compared to straight T-treated cells. Conclusion: So, in males 2 reasons 1) a deficiency of progesterone and 2) inefficiency of T to suppress endogenous IL-8 could possibly result in increased IL-8 levels. This increased IL-8 level in males could lead to increased cell growth and metastasis in melanoma (IL-8 had already been shown to stimulate melanoma cell growth and metastasis by us and others) leading to death. So, a situation arising out of male reproductive endocrine physiology could probably be responsible for increased male mortality in melanoma. Citation Format: Pandurangan Ramaraj. Is testosterone the male sex hormone responsible for increased male mortality in melanoma? In-vitro studies based on human melanoma (BLM) cell model. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5287.

Sex Hormones, Antioxidants and Lipid Profile of Aqueous Cucumis sativus L. (cucumber) Treated Male Rats

Background: Cucumis sativus (cucumber) is regarded as a healthy fruit because of the beneficial effects of its phytochemical constituents. However, there is a deficit of information about its effect on male reproductive physiology. Objective: This study was conducted to investigate the effect of aqueous extract of C. sativus (AECS) on male reproductive hormones, oxidative stress biomarkers, and lipid profile. Materials and Methods: Ten male rats were randomly assigned into two (control and treated) groups (n = 5). In the treated group, a single dose of AECS (500 mg/kg) was administered daily for 6 weeks and thereafter sacrificed under sodium pentobarbital anesthesia. Blood was collected and analyzed for sex hormones, antioxidants, and lipid profile markers. The testicular homogenate was also analyzed for antioxidants. Results: The AECS increased (P &lt; 0.05) serum testosterone and luteinizing hormone levels (4.43 ± 0.34 and 7.50 ± 1.31, respectively) when compared with the control. Also, testicular catalase and serum level of high-density lipoprotein were increased (27.45 ± 0.19 and 30.08 ± 5.22, respectively) (P &lt; 0.05), whereas serum low-density lipoprotein decreased (72.79 ± 9.56) (P &lt; 0.05) in the extract treated rats. However, serum antioxidant levels were not affected. Conclusions: AECS is beneficial to male reproductive physiology evidenced by improved lipid profile and hormonal indices. Also, the integrity of the testicular redox profile was well maintained.

PPP2R2A promotes testosterone secretion in Hu sheep Leydig cells via activation of the AKT/mTOR signaling pathway.

The serine-threonine protein phosphatase 2A (PP2A) is a heterotrimeric enzyme complex that plays a vital role in regulating male reproductive activities. However, as an essential member of the PP2A family, the physiological functions of PP2A regulatory subunit B55α (PPP2R2A) in testis remain inconclusive. Hu sheep are noted for their reproductive precocity and fertility, and are ideal models for the study of male reproductive physiology. Here, we analyzed the expression patterns of PPP2R2A in the male Hu sheep reproductive tract at different developmental stages and further investigated its role in testosterone secretion and its underlying mechanisms. In this study, we found that there were temporal and spatial differences in PPP2R2A protein expression in the testis and epididymis, especially the expression abundance in the testis at 8 months old (8M) was higher than that at 3 months old (3M). Interestingly, we observed that PPP2R2A interference reduced the testosterone levels in the cell culture medium, which is accompanied by a reduction in Leydig cell proliferation and an elevation in Leydig cell apoptosis. The level of reactive oxygen species in cells increased significantly, while the mitochondrial membrane potential (ΔΨm) decreased significantly after PPP2R2A deletion. Meanwhile, the mitochondrial mitotic protein DNM1L was significantly upregulated, while the mitochondrial fusion proteins MFN1/2 and OPA1 were significantly downregulated after PPP2R2A interference. Furthermore, PPP2R2A interference suppressed the AKT/mTOR signaling pathway. Taken together, our data indicated that PPP2R2A enhanced testosterone secretion, promoted cell proliferation, and inhibited cell apoptosis in vitro, all of which were associated with the AKT/mTOR signaling pathway.

Population density does not affect seasonal regulation of reproductive physiology in male water voles.

Most small rodent species display cyclic fluctuations in their population density. The mechanisms behind these cyclical variations are not yet clearly understood. Density-dependent effects on reproductive function could affect these population variations. The fossorial water vole ecotype, Arvicola terrestris, exhibits multi-year cyclical dynamics with outbreak peaks. Here, we monitored different water vole populations over 3 years, in spring and autumn, to evaluate whether population density is related to male reproductive physiology. Our results show an effect of season and inter-annual factors on testis mass, plasmatic testosterone level, and androgen-dependent seminal vesicle mass. By contrast, population density does not affect any of these parameters, suggesting a lack of modulation of population dynamics by population density.

Vasopressin V1a receptor and oxytocin receptor regulate murine sperm motility differently.

Specific receptors for the neurohypophyseal hormones, arginine vasopressin (AVP) and oxytocin, are present in the male reproductive organs. However, their exact roles remain unknown. To elucidate the physiological functions of pituitary hormones in male reproduction, this study first focused on the distribution and function of one of the AVP receptors, V1a. In situ hybridization analysis revealed high expression of the Avpr1a in Leydig cells of the testes and narrow/clear cells in the epididymis, with the expression pattern differing from that of the oxytocin receptor (OTR). Notably, persistent motility and highly proportional hyperactivation were observed in spermatozoa from V1a receptor-deficient mice. In contrast, OTR blocking by antagonist atosiban decreased hyperactivation rate. Furthermore, AVP stimulation could alter the extracellular pH mediated by the V1a receptor. The results highlight the crucial role of neurohypophyseal hormones in male reproductive physiology, with potential contradicting roles of V1a and OTR in sperm maturation. Our findings suggest that V1a receptor antagonists are potential therapeutic drugs for male infertility.

A Review on the Potential Effects of Combination Treatments of Anti-microbial and Anti-inflammatory Drugs Towards Male Reproductive Physiology in Pneumonic Bucks

Pneumonia is the inflammation of lung parenchyma due to various organisms resulting in numerous manifestations and sequelae. The environment in the tropical regions provides optimal conditions for infection to occur in small ruminants. Mannheimiosis caused by Mannheimia haemolytica is the most frequent isolated bacteria causing pneumonia in small ruminants. The bacteria may cause an acute infection which can lead to death without proper diagnosis and treatment. To date, there are still scarce study on the effect of anti-microbial and anti-inflammatory treatments on reproductive physiology that warrants investigation. Hence, this review paper aims to focus on the possible effect of a combined usage of anti-microbial and anti-inflammatory treatments toward male reproductive physiology.

Abstract 2313: Na+/H+ exchanger 5 (NHE5) protein is a potential target for therapeutic interventions in altered Male Reproductive Physiology

Abstract 2313: Na+/H+ exchanger 5 (NHE5) protein is a potential target for therapeutic interventions in altered Male Reproductive Physiology

Sexual selection drives the coevolution of male and female reproductive traits in Peromyscus mice.

When females mate with multiple partners within a single reproductive cycle, sperm from rival males may compete for fertilization of a limited number of ova, and females may bias the fertilization of their ova by particular sperm. Over evolutionary timescales, these two forms of selection shape both male and female reproductive physiology when females mate multiply, yet in monogamous systems, post-copulatory sexual selection is weak or absent. Here, we examine how divergent mating strategies within a genus of closely related mice, Peromyscus, have shaped the evolution of reproductive traits. We show that in promiscuous species, males exhibit traits associated with increased sperm production and sperm swimming performance, and females exhibit traits that are predicted to limit sperm access to their ova including increased oviduct length and a larger cumulus cell mass surrounding the ova, compared to monogamous species. Importantly, we found that across species, oviduct length and cumulus cell density are significantly correlated with sperm velocity, but not sperm count or relative testes size, suggesting that these female traits may have coevolved with increased sperm quality rather than quantity. Taken together, our results highlight how male and female traits evolve in concert and respond to changes in the level of post-copulatory sexual selection.

NGF and the Male Reproductive System: Potential Clinical Applications in Infertility.

Infertility is a worldwide health issue defined by the World Health Organization (WHO) as the inability to establish a pregnancy after 12 months or more of regular and unprotected sexual intercourse. Male infertility etiology can be related to either congenital or acquired factors. The therapeutical approach to male infertility depends on the underlying causes and includes medical and surgical treatments. In recent studies, the potential role of nerve growth factor (NGF) in male reproductive physiology has been proposed. It has been hypothesized that neurotrophins might be involved in testis morphogenesis and regulation of several aspects of spermatogenesis. Moreover, it has been shown that NGF exerts its role on gonadotropin-releasing hormone (GnRH) neurons through the activation of the PKC/p-ERK1/2/p-CREB cascade, which leads to the activation of hypothalamic cells and the consequent activation of hypothalamus-pituitary-gonadal axis (HPG) with the secretion of GnRH. Lastly, it has been shown that the physiology of mature sperm is affected by both exogenous and endogenous NGF. The NGF impact on the HPG axis and its effect on GnRH neurons might be exploited in the therapy of male hypogonadism or used as a protective strategy against gonadal dysfunction related to chemotherapeutic agents. Moreover, the improving effect of NGF on sperm motility and vitality could be useful to enhance assisted reproduction outcomes. NGF could be supplemented to cryopreserved sperm samples to counteract the oxidative stress induced by the frozen and thawing processes. Indeed, the potential clinical applications of NGF in male infertility treatment have been discussed.

Dancing to a different tune: changing reproductive seasonality in an introduced chital deer population

Male and female reproductive behaviour is typically synchronised. In species such as those in the family Cervidae, reproductive timing is often cued by photoperiod, although in females, it can be dependent on body condition. When a species is introduced to a novel environment, the environment changes, or responses of the sexes to such cues differ, asynchronous reproductive behaviour between males and females may occur. We investigated the seasonality of reproductive behaviour in introduced chital deer in northern Queensland by examining male antler phase in relation to female conception rates. We then analysed the influence of different variables likely to affect the timing of male and female reproductive physiology. The lowest percentage of chital in hard antler in any 1 month in this study was 35% (Fig. 1), but the average value was closer to 50%, thus there was a seasonal peak in antler phase linked with photoperiod. Females conceived at any time of year, but were strongly influenced by the amount of rainfall 3 months prior to conception. This resulted in varying conception peaks year-to-year that often did not correspond to the male’s peak in hard antler. In this system, a proportion of males and females were physiologically and behaviourally ready to mate at any time of the year. We predict that differences in the timing of the peaks between the males and females will lead to increased reproductive skew (variation in reproductive success among individual males). This pattern may select for different mating strategies or physiological mechanisms to increase reproductive success.Fig. 1The average percentage of male chital deer in hard antler by month from 2014 to 2019 in north Queensland. Values above the bars indicate the total number of males that were sampled in each month and the error bars indicate the standard error. In the month with the lowest % males in hard antler in the entire study (November, 2017), 35% of males were in hard antler

SUPPRESSION OF MALE REPRODUCTIVE FUNCTION BY BROWN HT IN RAT

Objective: Brown HT is an extensively used food color. Our objective was to evaluate the possible toxic effect of Brown HT on male reproductive functions in rats. Methods: Brown HT was administered to male rats orally at 100, 200, and 400 mg/kg body weight/day for a period of 30 days. At the end of this period, different types of parameters related to male reproductive physiology and activities of different antioxidant enzymes were measured by spectrophotometric method using standard protocols. The serum hormonal levels were measured by Chemiluminescence Immuno Assay method using the kit. Results: We have observed significant decrease in mean body weight, gonado somatic index, number of epididymal sperms, percentage of motile sperms, and also decrease in serum level of luteinizing hormone, follicle-stimulating hormone (FSH), and testosterone in a dose dependent manner in Brown HT exposed rats. The activities of antioxidant enzymes such as superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase, and glutathione-S-transferase have been decreased and the level of malondialdehyde, a biomarker of lipid peroxidation has been increased significantly in exposed rats. Histopathology of testes also showed degeneration of germ cells in somniferous tubules in Brown HT exposed rats. Conclusion: According to this result, it is concluded that Brown HT suppresses the male reproductive functions probably by producing oxidative stress in testicular tissues and suppressing the hypothalamus-anterior pituitary-testicular axis in rat.