Relative Testicular Weight Research Articles

Perinatal exposure to parasiticide ivermectin: long-term effects on reproductive parameters of adult male rats

Ivermectin is one of the most widely used antiparasitic drugs globally. The aim of this study was to evaluate the chronic effects of perinatal exposure to ivermectin on male reproductive parameters in rats. Pregnant rats were treated daily by oral gavage with 0.4 or 1.6 mg kg−1 of ivermectin or vehicle, from gestational day 6 until post-natal day 10. In the adulthood stage, there were significant reductions in the relative testicular weight of rats exposed to the low dose and in relative prostate weight of male rats exposed to the high dose of ivermectin. Furthermore, the animals exposed to the low dose also presented an increased seminal vesicle weight compared to controls. However, neither of the ivermectin doses interfered in daily sperm production, sperm number in testis, or sexual behavior of exposed males. In conclusion, perinatal exposure to ivermectin neither altered the male reproductive system development markedly, nor produced any adverse effects on the parameters evaluated.

Protective effect of an aphrodisiac herb Tribulus terrestris Linn on cadmium-induced testicular damage

Aim:The aim of the present study was to investigate whether Tribulus terrestris Linn (TT) could protect the cadmium (Cd)-induced testicular tissue peroxidation in rats and to explore the underlying mechanism of the same.Materials and Methods:In vitro and in vivo studies were conducted to know the protective effect of ethanolic extract of TT (eTT) in Cd toxicity. In in vitro studies, total antioxidant and ferrous metal ion chelating activity of TT was studied. In vivo studies were conducted in rats. A total of 40 Wistar strain adult male rats were divided into four groups. Group 1 served as control, while group 2 to 4 received CdCl2 (3 mg/kg b. wt. s/c once a week). In addition to Cd, group 3 and 4 rats also received eTT (5 mg/kg b.wt. daily as oral gavage) and α-tocopherol (75 mg/kg daily by oral gavage), respectively. At the end of 6th week, all the rats were sacrificed and the separated testes were weighted and processed for estimation of tissue peroxidation markers, antioxidant markers, functional markers, and Cd concentration. The testes were also subjected to histopathological screening.Results:In in vitro studies, the percentage of metal ion chelating activity of 50 μg/ml of eTT and α-tocopherol were 2.76 and 9.39, respectively, and the antioxidant capacity of eTT was equivalent to 0.063 μg of α-tocopherol/μg of eTT. In in vivo studies, administration of Cd significantly reduced the absolute and relative testicular weight, antioxidant markers such as superoxide dismutase and glutathione, and functional markers such as LDH and ALP, along with significant increase in peroxidation markers such as malondialdehyde and protein carbonyls in testicular tissue. Testes of Cd only-treated group showed histological insults like necrotic changes in seminiferous tubules and interstitium, shrunken tubules with desquamated basal lamina, vacuolization and destruction of sertoli cells, and degenerating Leydig cells. This group also had higher Cd levels in testicular tissue. Co-treatment with eTT and α-tocopherol significantly reduced the Cd burden in the testes along with reversal of the Cd-induced changes.Conclusions:eTT exhibited protective effect against Cd-induced testicular damage. The protective effect appears to be mediated through inhibition of testicular tissue peroxidation by antioxidant and metal chelator activity and also, may be indirectly by stimulating the testosterone production from Leydig cells.

Methylphenidate has dose-dependent negative effects on rat spermatogenesis: decreased round spermatids and testicular weight and increased p53 expression and apoptosis

In the present study, we aimed to evaluate the possible effects of methylphenidate on rat testes. Forty-two Wistar rats were randomly distributed into three experimental groups of 14 rats each. For 90 days, each group via gavage received the following: group 1 = tap water (control group), group 2 = 5 mg/kg/day of ritalin (methylphenidate, MPH), and group 3 = 10 mg/kg/day of ritalin. After sacrificing the animals, the body weights as well as the absolute and relative testicular weights were measured. Testes were sampled, fixed, and processed and, by histopathological examination, quantitative morphometric analysis of Sertoli cells, spermatocytes, and spermatids was performed in stages II, V, and XII. Immunohistochemistry was performed for transforming growth factor (TGF)-β1 and p53, and the apoptotic index was assessed through the TUNEL method. Group 2 had a reduction of round spermatids in stage II. Group 3 had reduction in both stage II and stage V spermatids, as well as lower testicular weight. The p53 expression was increased in group 3. In groups 2 and 3, the TGF-β1 expression was reduced and the apoptotic index by TUNEL was increased. Body weights remained stable on either group. Our results showed that methylphenidate might negatively affect spermatogenesis not only by reducing testicular weight and amount of round spermatids but also by increasing apoptotic death and p53 activation. The findings of the study, however, must be cautiously interpreted.

The effects of bisphenol A on sex hormone levels of F0 female rats and F1 male rats during weaning period

The effects of bisphenol A (BPA) were examined on sex hormones of F1 generation male rats during weaning period. Female rats were exposed to BPA from day 0 after pregnancy to the weaning period at doses of 50, 100, or 200 mg kg−1. The sex hormone levels of F1 generation male rats were determined. This study shows that F0 generation female rats fed with 200 mg kg−1 BPA had a significantly higher serum prolactin (PRL) levels at the end of weaning. Significantly higher levels of serum estradiol (E2) were also found in female rats fed 100 or 200 mg kg−1 BPA. Serum levels of E2 in F1 male generation rats were higher in treatment groups compared to control groups while serum testosterone (T) levels were lower. Follicle stimulating hormone (FSH) in F1 generation rats fed 200 mg kg−1 was markedly decreased. The relative testicular weights were significantly less in 100 and 200 mg kg−1 BPA groups. BPA was found to alter the sex hormone levels in F1 male rats during weaning period and thus disrupted endocrine functions.

Long-term ofloxacin testicular toxicity: an experimental study

The aim of this study was to assess the long-term toxic effect of ofloxacin on the testes and epididymides of 72 adult male albino rats. The rats were divided into group A and group B. Group A, which received ofloxacin for 14 days, was subdivided into two subgroups; LD-14 received low dose 72 mg KBW(-1) daily and HD-14 received high dose 216 mg KBW(-1) daily. Group B, which received ofloxacin for 28 days, was subdivided into two subgroups; LD-28 received 72 mg KBW(-1) and HD-28 received 216 mg KBW(-1) daily. Two matched control groups were followed up for 14 and 28 days respectively. The animals were evaluated for body weight, testicular weight, relative testicular weight, serum testosterone (T), epididymal sperm analysis (sperm count, motility, morphology, curvilinear velocity, linear velocity and linearity index) and testicular histopathology. The adverse effects of ofloxacin were correlated with increased treatment duration and/or dose. It is concluded that long-term ofloxacin has a direct detrimental effect on the testicles of albino rats at the studied doses and durations.

Mesterolone (Proviron) induces low sperm quality with reduction in sex hormone profile in adult male Sprague Dawley rats testis

Anabolic-androgenic steroid compounds are one of the most widely abused drugs by athletes and muscle builders with the goal of improving performance/muscle mass. However, increasing concern has been expressed because these compounds not only offer unappreciable benefits to infertile and subfertile males, but also might have deleterious effects on both human and animal physiology including sperm quality. In addition, there is the conflicting outcome of AAS usage in the clinical settings with its attendant reduced spermatogenesis and hypopituitarism in patient management. Hence, we aim to evaluate the effects of mestorolone, an anabolic-androgenic steroid, on the histomorphometry of seminiferous tubules with serum hormonal and seminal analyses in adult male Sprague-Dawley rat. Twenty adult male Sprague dawley rats divided into two groups of 10 each. The treated group received 0.06 mg/g body weight/ day of mesterolone (proviron) by oral gavage for six weeks while the control group received equal volume of 0.9% normal saline per day. SPSS analysis of data generated with P< 0.05 considered statistically significant. The result showed significant (P< 0.05) body weight gain in all the animals. However, both the raw testicular weight and relative testicular weight per 100 g bwt was significantly (P< 0.05) higher in control than treated. The mean sperm count significantly decreased by 28% (P< 0.05) and the motility reduced significantly by 56% (P< 0.05) in the treated compared to control. In addition, both FSH (follicle stimulating hormone) and T (testosterone) of the treated were significantly lowered by 73% (P< 0.05) and 63% (P< 0.05) respectively compared to the control. The use of mesterolone is with caution and short intermittent therapy is desirous for better semen quality and improved overall fertility. Key words: Proviron, sperm parameters, germ cells, stereology, hormonal profiles, Sprague dawley rats.

Effects of diallyl sulfide and zinc on testicular steroidogenesis in cadmium‐treated male rats

Cadmium (Cd) is one of the environmental pollutants that affect various tissues and organs including testis. Harmful effect of cadmium on testis is known to be germ cell degeneration and impairment of testicular steroidogenesis. In the present study, the effect of diallyl sulfide (DAS), a sulfur-containing volatile compound present in garlic, and zinc (Zn) was investigated on cadmium-induced testicular toxicity in rats. Male adult Wistar rats treated with cadmium (2.5 mg/kg body wt, five times a week for 4 weeks) showed decreased body weight, paired testicular weight, relative testicular weight, serum testosterone, luteinizing hormone, follicle-stimulating hormone, and testicular total antioxidant capacity (TAC) and protein levels. Testicular steroidogenic enzymes, such as 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and 17beta-hydroxysteroid dehydrogenase (17beta-HSD), and marker enzymes, such as sorbitol dehydrogenase (SDH), lactate dehydrogenase (LDH), acid phosphatase (ACP), alkaline phosphatase (ALP), and glucose-6-phosphate dehydrogenase (G6PD), showed a significant decrease in activities whereas that of gamma-glutamyl transferase was significantly increased after cadmium exposure. The results have revealed that concurrent treatment with DAS or zinc restored key steroidogenic enzymes, SDH, LDH, and G6PD and increased testicular weight significantly. DAS restored the TAC level and increased testosterone level and relative testicular weight significantly. Zinc restored testicular protein level and body weight. It can be concluded that cadmium causes testicular toxicity and inhibits androgen production in adult male rats probably by affecting pituitary gonadotrophins and that concurrent administration of DAS or zinc provides protection against cadmium-induced testicular toxicity.

Effects of Boesenbergia rotunda (L.) Mansf. on sexual behaviour of male rats

To study the effects of Boesenbergia rotunda (Krachai) on sexual behaviour in male albino rats. Thirty-two male Wistar rats were equally divided into four groups: experimental groups were gavaged with the ethanolic extract of the rhizome of B. rotunda at doses of 60, 120 and 240 mg/kg and a control group received distilled water, for 60 days. Sexual behaviour, reproductive organs, diameter of seminiferous tubule, epididymal sperm density, and androgenic hormones were evaluated. Within 30-min observation, there was no significant difference of courtship behaviour, mount frequency (MF), intromission frequency (IF), mount latency (ML), intromission latency (IL), copulatory efficiency or intercopulatory interval in male rats. In three 10-min intervals over a 30-min period, courtship behaviour and MF during the first 10-min were significantly higher than those in the second and third 10-min observation in all groups, whereas IF had no significant difference. All doses of B. rotunda extract significantly increased the relative testicular weight and the diameter of the seminiferous tubules. The dose of 60 mg/kg also significantly increased the relative weight of the seminal vesicle. Nevertheless, the sperm density, serum testosterone and androstenedione levels were not affected by the B. rotunda extract. B. rotunda does not affect sexual behaviour nor serum androgenic levels.

Curcumin and Kolaviron Ameliorate Di‐n‐Butylphthalate‐Induced Testicular Damage in Rats

The present study was carried out to evaluate the ameliorative effects of kolaviron (a biflavonoid from the seeds of Garcinia kola) and curcumin (from the rhizome, Curcuma longa L.) on the di-n-butylphthalate (DBP)-induced testicular damage in rats. Administration of DBP to rats at a dose of 2 g/kg for 9 days significantly decreased the relative testicular weights compared to the controls, while the weights of other organs remained unaffected. Curcumin or kolaviron did not affect all the organ weights of the animals. While only DBP treatment significantly increased the testicular malondialdehyde level and gamma-glutamyl transferase activity (gamma-GT), it markedly decreased glutathione level, the testicular catalase, glucose-6-phosphate dehydrogenase, superoxide dismutase, sperm gamma-GT activities and serum testosterone level compared to the control group. Data on cauda epididymal sperm count and live/dead ratio were not significantly affected in the DBP-treated rats. Alone, DBP treatment resulted in a 66% decrease in spermatozoa motility and a 77% increase in abnormal spermatozoa in comparison to control. DBP-treated rats showed marked degeneration of the seminiferous tubules with necrosis and defoliation of spermatocytes. The DBP-induced injuries in biochemical, spermatological parameters and histological structure of testis were recovered by treatment with kolaviron or curcumin. The pattern in the behaviour of these compounds might be correlated with their structural variations. Our results indicate that kolaviron and curcumin protect against testicular oxidative damage induced by DBP. The chemoprotective effects of these compounds may be due to their intrinsic antioxidant properties and as such may prove useful in combating phthalate-induced reproductive toxicity.

Evaluation of single intratesticular injection of calcium chloride for nonsurgical sterilization of male Black Bengal goats ( Capra hircus): a dose-dependent study

This study describes the induction of chemosterilization in three groups each of six adult male Black Bengal goats at 30 days after a single bilateral intratesticular injection of a calcium chloride (CaCl 2, 2H 2O) solution at the doses of 10, 20 or 40 mg/kg body weight/testis, always in a 2 ml volume of normal saline. Another one group of animals received only 2 ml of normal saline per testis as a control. The induction of chemosterilization was measured using relative testicular weight as well as histomorphological parameters including seminiferous tubular architecture and germ cell association in seminiferous tubules along with morphology of the interstitial space. Biochemical markers included activities of testicular Δ 5, 3β-hydroxysteroid dehydrogenase (Δ 5, 3β-HSD), 17β-hydroxysteroid dehydrogenase (17β-HSD), catalase, glutathione peroxidase (GPx), glutathione S-transferase (GST) and superoxide dismutase (SOD) as well as monitoring the level of testicular thiobarbituric acid reactive substances (TBARS), conjugated dienes and reduced glutathione (GSH) content along with plasma concentrations of testosterone, LH and FSH. Histomorphological measures of testes showed total necrosis of testicular tissue at 30 days after an injection of either 20 or 40 mg CaCl 2 along with fibrosis in seminiferous tubules and interstitial spaces. Infiltration of leucocytes was observed with the 40 mg dose. Disintegration of germ cell arrangement in seminiferous tubules and washing out of germ cells from the tubules were noted with the 10 mg dose. Relative organ weights, plasma concentrations of testosterone, testicular activities of Δ 5, 3β-HSD, 17β-HSD, catalase, GPx, GST, and SOD and testicular contents of GSH all were declined. Increases occurred in testicular TBARS, conjugated dienes and plasma concentrations of LH and FSH with each of the treatments by comparison with the control group. Plasma concentrations of cortisol and fasting blood sugar level as well as packed cell volume (PCV) and total plasma protein were recorded to monitor the changes of chronic stress in the experimental animals. Changes in these parameters were not significant. An intratesticular injection of calcium chloride at specified doses could be a suitable method of sterilization in preference to surgical castration of goats.

Phytoestrogens alter the reproductive organ development in the mink ( Mustela vison)

The aim of the present study was to examine the reproductive effects of two perorally applied phytoestrogens, genistein (8 mg/kg/day) and β-sitosterol (50 mg/kg/day), on the mink ( Mustela vison) at human dietary exposure levels. Parental generations were exposed over 9 months to these phytoestrogens and their offspring were exposed via gestation and lactation. Parents and their offspring were sampled 21 days after the birth of the kits. Sex hormone levels, sperm quality, organ weights, and development of the kits were examined. The exposed females were heavier than the control females at the 1st postnatal day (PND). The control kits were heavier than the exposed kits from the 1st to the 21st PND. Phytoestrogens did not affect the organ weights of the adult minks, but the relative testicular weight of the exposed kits was higher than in the control kits. The relative prostate weight was higher and the relative uterine weight lower in the β-sitosterol-exposed kits than in the control kits. Moreover, the plasma dihydrotestosterone levels were lower in the genistein-exposed male kits compared to the control male kits. This study could not explain the mechanisms behind these alterations. The results indicate that perinatal phytoestrogen exposures cause alterations in the weight of the reproductive organs of the mink kits.

Male reproductive toxicity of sodium arsenite in mice.

The effect of chronic oral exposure to arsenic on male mouse testicular and accessory sex organ weights, sperm parameters and testicular marker enzymes was studied. In addition, the distribution of arsenic in reproductive organs was measured using atomic absorption spectrophotometry. Sodium arsenite administered to mice (Mus musculus) via drinking water at a dose of 53.39 micromol/L (4 ppm As) for 365 days caused a decrease in the absolute and relative testicular weight. However, epididymal and accessory sex organ weight was similar to control. The activities of marker testicular enzymes such as sorbitol dehydrogenase, acid phosphatase and 17beta-hydroxy-steroid dehydrogenase (17beta-HSD) were significantly decreased, but those of lactate dehydrogenase and gamma-glutamyl transpeptidase (gamma-GT) were significantly increased. A decrease in sperm count and sperm motility, along with an increase in abnormal sperm, was observed in arsenite-exposed mice. A significant accumulation of arsenic in testes, epididymis, seminal vesicle and prostate gland was observed in treated animals. Thus long term exposure (365 days) at the dose level of 53.39 micromol/L sodium arsenite (4 ppm As), to which human beings are likely to be exposed via drinking water, may cause testicular and spermatotoxic effect.

Testicular effects of sub-chronic administration of Hibiscus sabdariffa calyx aqueous extract in rats

The sub-chronic effect of Hibiscus sabdariffa (HS) calyx aqueous extract on the rat testes was investigated with a view to evaluate the pharmacological basis for the use of HS calyx extract as an aphrodisiac. Three test groups received different doses of 1.15, 2.30, and 4.60 g/kg based on the LD 50. The extracts were dissolved in the drinking water. The control group was given equivalent volume of water only. The animals were allowed free access to drinking solution during the 12-week period of exposure. At the expiration of the treatment period, animals were sacrificed, testes excised and weighed, and epididymal sperm number recorded. The testes were processed for histological examination. Results did not show any significant ( P>0.05) change in the absolute and relative testicular weights. There was, however, a significant ( P<0.05) decrease in the epididymal sperm counts in the 4.6 g/kg group, compared to the control. The 1.15 g/kg dose group showed distortion of tubules and a disruption of normal epithelial organization, while the 2.3 g/kg dose showed hyperplasia of testis with thickening of the basement membrane. The 4.6 g/kg dose group, on the other hand, showed disintegration of sperm cells. The results indicate that aqueous HS calyx extract induces testicular toxicity in rats.

Reproductive and aggressive behavior in male broiler breeders with varying fertility levels

Differential male fertility in naturally mated broiler breeders appears to be an inadvertent negative result of genetic selection for growth and high yield. Identifying male behaviors that reliably indicate fertility could improve production while avoiding artificial insemination procedures. We hypothesized subfertile males to display less courtship, attempt more forced matings, and have smaller secondary sexual characters. An age-related decline in the frequency of reproductive display was predicted. Males individually housed with an average of 10 females from two primary broiler breeder strains ( n=30 males per strain; A and B) were studied at five age periods from 30 to 51 weeks of age. Male reproductive behavior was recorded for 30 min per male at each age period. Fertility was determined by visual examination of the blastodisc of fresh-laid eggs, and comb area was measured by digital image analysis. Body weight (BW) and relative testicular weight were measured at age period 5. Age and strain effects upon behavioral frequency and the level of fertility were analyzed by mixed model repeated measures ANOVA; Kendall correlations were used to determine linear relationships between the reproductive traits and fertility levels. Our results indicated that Strain A displayed more of courtship behavior, particularly wing flapping ( P<0.001) and waltzing ( P<0.05) than Strain B. Frequency of wing flapping ( P<0.05), waltzing ( P<0.001), cloacal contacts ( P<0.05), total forced mating behavior ( P<0.001), and aggression ( P<0.05) declined with age in both strains. The frequency of forced matings was higher in Strain A than in Strain B at age period 1 ( P<0.05), while Strain B mounted less frequently ( P<0.01) and displayed less total reproductive behavior ( P<0.05) by age period 3. Relative testicular weight was positively correlated with Strain A comb area ( P<0.01), total reproductive behavior ( P<0.05), crowing ( P<0.05), and wing flapping P<0.001). Total reproductive behavior ( P<0.05) and wing flapping ( P<0.01) positively correlated with Strain A fertility, therefore reproductive behavior may reliably indicate fertility in this strain. Unexpectedly, reproductive display positively correlated with the frequency of forced mating behavior as well ( P<0.05). Heavier Strain B males displayed less total reproductive behavior ( P<0.05), therefore may face physical limitations on their ability to display high-intensity courtship.

Safety evaluation of an extract from Salacia oblonga

Plant extracts from the Salacia genus have been found to have intestinal α-glucosidase inhibitor activity, which may have application to the development of medical foods for people with diabetes. We evaluated the safety of a hot water extract of S. oblonga (salacinol extract) supplemented to or processed into a medical food. Thirty male Sprague–Dawley rats were assigned among one of three treatments: (1) EN-0178 (control, liquid diet), (2) EN-0178+salacinol (as 1 plus 500 mg of salacinol extract per 253 g diet, which was added to product immediately prior to feeding), (3) EN-0195 (as 1 plus 500 mg of salacinol extract per 253 g diet, which was added during product manufacture). After 14 days of free access to dietary treatments, rats were sacrificed, blood collected and organs weighed. Rats consuming salacinol extract had reduced ( P <0.05) weight gain and feed intake. The relative (% of body weight) testicular weight was higher ( P<0.05) for rats consuming salacinol extract, whereas, the relative liver and spleen weight was lower ( P<0.05) for rats consuming salacinol extract. Of the serum chemistries analyzed, blood urea nitrogen and alkaline phosphatase was lower ( P<0.05) for rats consuming salacinol extract. No differences in blood hematology were found. We conclude that salacinol extract, in a medical food consumed for 2 weeks in amounts estimated at 10-fold greater than proposed for human intake, did not result in clinical chemistry or histopathologic indications of toxic effects in male Sprague–Dawley rats.

Phenotypic Traits as Reliable Indicators of Fertility in Male Broiler Breeders

Genetic selection procedures applied to improve broiler performance may negatively impact the subsequent reproductive efficiency of breeders, particularly in males. Identification of traits that reliably indicate individual male fertility would facilitate selection for reproduction. We hypothesized that physical traits, such as comb area, relative testicular weight, and testicular weight asymmetry, may correlate with fertility in two male-selected primary broiler breeder strains (A and B). Thirty males per strain, individually housed with an average of 10 females, were evaluated at five age periods within the 30-to-50-wk breeding cycle. Flock fertility by candling eggs at Day 19 of incubation and sample fertility by visual assessment of the germinal disc were determined. Sperm penetration (SP) through the perivitelline layer was assessed. Comb area was evaluated by image analysis at 40 and 50 wk, and relative testicular weight was measured at 50 wk. Strain A sample and flock fertility (P < 0.001) and SP values (P < 0.0001) were significantly lower than Strain B. Both strains had a significant decline of fertility and SP with age (P < 0.0001). Strain A comb area correlated with sample fertility (P < 0.05), flock fertility (P < 0.05), and relative testicular weight (P < 0.01). Conversely, Strain B relative testicular weight correlated with sample fertility (P < 0.0001) and flock fertility (P < 0.001). Significant correlations were not found between testicular weight asymmetry and other reproductive traits. Results suggest comb area may be a reliable indicator of male fertility in Strain A.

ADVERSE EFFECTS OF NEONATAL HYPOTHYROIDISM ON WISTAR RAT SPERMATOGENESIS

The effect of neonatal hypothyroidism on spermatogenesis was studied in Wistar rats of different age groups. Hypothyroidism was induced in newborn male rats from day one postpartum up to day 60 postpartum by daily administration of 0.05% methimazole (MMI) to the nursing mothers or directly through drinking water. The animals were killed at days 10, 15, 30, 40, and 60 postpartum, blood plasma was collected, and testes, epididymides, prostates, and seminal vesicles were separated and weighed. Testes were fixed in formalin for histological studies. Plasma testosterone (T), estradiol (E2), and sex hormone binding globulin (SHBG) were measured by radioimmunoassay. Hypothyroidism significantly reduced seminiferous tubule and lumen diameter. Control rats showed active spermatogenesis whereas in hypothyroid rats, the proliferation and differentiation of germ cells were arrested and their number was decreased. Plasma T, E2, and SHBG levels were significantly decreased at all ages for hypothyroid rats. The absolute weight of testes was decreased irrespective of age (except day 10 postpartum), however ventral, dorsolateral prostate, and epididymis weights were decreased at 30, 40, and 60 days postpartum. Coagulating gland weight was decreased in all age groups of hypothyroid rats. Hypothyroid rats of day 40 and 60 postpartum showed a decrease in absolute seminal vesicle weight. Relative testicular weights of hypothyroid rats decreased by postpartum day 15, 30, 40, and 60 whereas the opposite effect was observed by postpartum day 10. Relative organ weights were increased in epididymides (day 15 and 30 postpartum), seminal vesicles (day 30 and 40 postpartum), and dorsolateral prostates (day 15, 30, and 40 postpartum) and decreased in 10 and 60 day old hypothyroid rat. Ventral prostate relative weight was decreased in 40 and 60 day old rats. The coagulating gland weight was decreased in 10, 15, and 60 days postpartum and an opposite effect was observed in 30 and 40 days hypothyroid rats. The present study clearly indicates that hypothyroidism adversely affects spermatogenesis; it also indicates that thyroid hormones are essential for normal spermatogenesis. Their effect may either be direct or indirect.

Impact of vinclozolin on reproductive behavior and endocrinology in Japanese quail (Coturnix coturnix japonica)

AbstractThe impact of endocrine‐disrupting chemicals (EDCs) has been demonstrated in mammalian models, but less research is available for avian species. The effects of vinclozolin (VIN), an antiandrogenic fungicide, on sexual differentiation and maturation were investigated in Japanese quail (Coturnix coturnix japonica). On day 4 of incubation, embryos were exposed to no treatment, oil, or 25, 50, or 100 ppm of VIN. Endpoints measured included adult male reproductive behavior, hypothalamic gonadotropin‐releasing hormone I (GnRH‐I) content in hatchlings and adults, plasma steroid levels in hatchlings and adults, proctodeal gland growth during maturation, and relative testicular weight at seven weeks of age. Results showed that exposure to VIN significantly (p &lt; 0.05) altered GnRH‐I in male hatchlings, whereas GnRH‐I levels in females remained unaffected. Although steroid levels were unaltered by any VIN treatment, the display of male reproductive behavior seemed delayed, with the number of mounts and the number of cloacal contacts being significantly (p &lt; 0.05) lower in the VIN‐treated males. This could have an extreme negative impact on wild avian species that are routinely exposed to similar EDCs.

Low-dose mercury induces testicular damage protected by zinc in mice

Objectives: This investigation was set out to determine whether mercury at a very low dose (4 ppm) induces testicular damage on murine testis, and if so whether the toxic effects of mercury could be prevented by zinc. Study Design: One of the following solutions was administered in the drinking water of CD-1 male mice: (1) 4 ppm HgCl 2; (2) 800 ppm ZnCl 2; (3) 4 ppm HgCl 2+800 ppm ZnCl 2; or (4) deionised water; for 12 weeks. At the expiration of the treatment period, animals were sacrificed, testes excised and weighed, and epididymal sperm number taken. The testes were processed for histological examination. Results: Both zinc and mercury significantly ( p<0.05) decreased the absolute and relative testicular weights, with mercury producing the highest reduction in weight. Mercury reduced significantly ( p<0.05) the epididymal sperm number, while zinc and mercury/zinc produced statistically same effect with control on the sperm number. Histological study showed that mercury at the concentration employed produced remarkable degenerative lesions on the testes, as the zinc-treated group showed a normal morphology. Majority of the animals in the mercury/zinc-treated group exhibited complete or partial protection as evidenced by the morphology of the seminiferous tubules. Conclusion: Zinc prevents mercury-induced testicular damage in mouse. These findings highlight the risks exposure to inorganic mercury might pose to male reproduction of mice, and suggests possible therapy with zinc. Study in humans is therefore advocated.

Impact of vinclozolin on reproductive behavior and endocrinology in Japanese quail (Coturnix coturnix japonica).

The impact of endocrine-disrupting chemicals (EDCs) has been demonstrated in mammalian models, but less research is available for avian species. The effects of vinclozolin (VIN), an antiandrogenic fungicide, on sexual differentiation and maturation were investigated in Japanese quail (Coturnix coturnix japonica). On day 4 of incubation, embryos were exposed to no treatment, oil, or 25, 50, or 100 ppm of VIN. Endpoints measured included adult male reproductive behavior, hypothalamic gonadotropin-releasing hormone I (GnRH-I) content in hatchlings and adults, plasma steroid levels in hatchlings and adults, proctodeal gland growth during maturation, and relative testicular weight at seven weeks of age. Results showed that exposure to VIN significantly (p < 0.05) altered GnRH-I in male hatchlings, whereas GnRH-I levels in females remained unaffected. Although steroid levels were unaltered by any VIN treatment, the display of male reproductive behavior seemed delayed, with the number of mounts and the number of cloacal contacts being significantly (p < 0.05) lower in the VIN-treated males. This could have an extreme negative impact on wild avian species that are routinely exposed to similar EDCs.