SPERM QUALITY IN ADULT MALE RATS EXPOSED TO CADMIUM IN UTERO and LACTATION

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphology and histology of male and female reproductive systems in the inseminating species Scoloplax distolothrix (Ostariophysi : Siluriformes : Scoloplacidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of Gestational and Lactational Fenvalerate Exposure on Immune and Reproductive Systems of Male Rats

The aim of this study was to determine the consequent reproductive developmental and immunotoxic effects due to exposure to fenvalerate during pregnancy and lactation in male offspring of maternal-treated rats. Pregnant rats were treated daily by oral gavage with 40 or 80 mg/kg of fenvalerate or corn oil (vehicle, control), from d 12 of pregnancy to d 21 of lactation. Immune and reproductive developmental effects were assessed in male offspring at postnatal days (PND) 40 (peripuberty), 60 (postpuberty), and 90 (sexual maturity). Treatment with the higher dose (80 mg/kg) resulted in convulsive behavior, hyperexcitability, and mortality in 45% of the dams. Fenvalerate was detected in the fetus due to placental transfer, as well as in pups due to breast-milk ingestion, persisting in male offspring until PND 40 even though pesticide treatment was terminated on PND 20. However, fenvalerate did not produce marked alterations in age of testicular descent to the scrotum and prepucial separation, parameters indicative of puberty initiation. In contrast, at puberty, there was a reduction in testicular weight and sperm production in male offspring of maternal-treated rats. At adulthood, the sperm counts and fertility did not differ between control and treated groups. Testosterone levels were not changed at any time during reproductive development. Similarly, no apparent exposure-related effects were detected in the histological structures of the lymphohematopoietic system. Data indicate that fenvalerate, in this experimental model, interfered with initial development of the male reproductive system, but that these effects on sperm production or fertility did not persist into adulthood. There was no apparent evidence that fenvalerate altered testosterone levels or produced a disruption in male endocrine functions.

In utero protein restriction causes growth delay and alters sperm parameters in adult male rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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. © 2011 Taylor & Francis.

The reproductive cycle of the male sleep snake Sibynomorphus mikanii (Schlegel, 1837) from southeastern brazil

This study describes the male reproductive cycle of Sibynomorphus mikanii from southeastern Brazil considering macroscopic and microscopic variables. Spermatogenesis occurs during spring-summer (September-December) and spermiogenesis or maturation occurs in summer (December-February). The length and width of the kidney, the tubular diameter, and the epithelium height of the sexual segment of the kidney (SSK) are larger in summer-autumn (December-May). Histochemical reaction of the SSK [periodic acid-Schiff (PAS) and bromophenol blue (BB)] shows stronger results during summer-autumn, indicating an increase in the secretory activity of the granules. Testicular regression is observed in autumn and early winter (March-June) when a peak in the width of the ductus deferens occurs. The distal ductus deferens as well as the ampulla ductus deferentis exhibit secretory activities with positive reaction for PAS and BB. These results suggest that this secretion may nourish the spermatozoa while they are being stored in the ductus deferens. The increase in the Leydig cell nuclear diameter in association with SSK hypertrophy and the presence of sperm in the female indicate that the mating season occurs in autumn when testes begin to decrease their activity. The peak activity of Leydig cells and SSK exhibits an associated pattern with the mating season. However, spermatogenesis is dissociated of the copulation characterizing a complex reproductive cycle. At the individual level, S. mikanii males present a continuous cyclical reproductive pattern in the testes and kidneys (SSK), whereas at the populational level the reproductive pattern may be classified as seasonal semisynchronous. © 2012 Wiley Periodicals, Inc.

Structure, histochemistry and ultrastructure of the male reproductive accessory glands in the neotropical flat-faced fruit-eating bat Artibeus planirostris (Chiroptera: Phyllostomidae)

Chiroptera, the second largest mammalian order, presents different reproductive strategies and unique reproductive features. However, there are few reports regarding male reproductive accessory glands (RAGs) in Chiroptera. Thus, the aim of the present study was to characterise the RAGs of the exclusively neotropical bat Artibeus planirostris (Chiroptera: Phyllostomidae) macroscopically, microscopically and ultrastructurally. The RAGs were composed of a prostatic complex with two regions (ventral and dorsal) and paraurethral and bulbourethral glands, but no seminal vesicles. The ventral region had an undefined epithelium, with secretory and basal cells, and its secretions were periodic acid-Schiff (PAS) positive. The dorsal region received both deferens ducts, had a columnar pseudostratified epithelium with secretory and basal cells. There were two types of secretions from the dorsal region: one that was basophilic and another that was mixed PAS positive and PAS negative. The paraurethral glands were dispersed in the connective tissue of the urethra, whereas the bulbourethral glands were located in the penile root. Histological and ultrastructural data confirmed the prostatic nature of the ventral and dorsal regions and the holocrine nature of the ventral region, with the latter finding never having been described previously for the prostate gland. Our findings demonstrate the wide discrepancy of RAGs between A. planirostris and other mammals in terms of their composition, structure and morphology. © CSIRO 2013.

Functional morphology of the reproductive system and sperm transfer in Stenopus hispidus (Crustacea: Decapoda: Stenopodidea), and their relation to the mating system

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Lack of reproductive toxicity in adult male rats exposed to interferon-alpha

Interferon-alpha (IFN- α ), a type I IFN, is a protein with antiviral, antiproliferative, and immunoregulatory activities, widely used in the treatment of several types of cancers as well as hepatitis B and C. Decrease of libido and erectile dysfunction are commonly reported by male patients during treatment of chronic hepatitis C with IFN- α . However, IFN therapy-associated underlying factors attributed to sexual dysfunction are still not well defined. Currently, there are few studies investigating the effects of IFN on male reproductive system functions. Given that, the aim of the present investigation was to examine effects of subchronic exposure to IFN- α (5 × 10(4) U/kg and 10 × 10(4) U/kg, 30 d) on serum hormones, sperm parameters, fertility, and testicular and epididymal hystopathology and morphometry in adult male Wistar rats. None of the evaluated parameters was markedly altered by IFN- α . Thus, our results suggest that exposure to IFN- α , in this experimental design, did not adversely affect sperm quality and fertile capacity of male rats.

Safety assessment of after maternal exposure on male reproductive parameters in rats

Context: Hibiscus sabdariffa L. (Malvaceae) is a species widely used in folk medicine for the treatment of some disorders. Objective: This study evaluated the effects of H. sabdariffa (HS) on the development of the male reproductive tract in rats following in utero exposure. Materials and methods: Pregnant rats received 250 or 500 mg/kg of HS extract or vehicle from gestational day 12 until day 21 of lactation. Results and discussion: Both doses of HS increased the body weight of male offspring at weaning, without compromising the puberty onset parameters. At puberty, there was a significant increase in the vas deferens absolute weight and a significant reduction in the relative weight of kidney at higher dose. These animals also presented a significant reduction in the sperm number in the caput/corpus of epididymis after exposure to both doses and a reduction in the sperm number in the cauda epididymis for the lower dose. At adulthood, the highest dose significantly reduced the sperm production in relation to controls and both doses provoked a reduction in the relative sperm number in the epididymis without affecting the sperm morphology. Conclusion: These findings demonstrated that maternal exposure to H. sabdariffa can adversely influence the male reproductive system in rats.

Complex genital system of a haplogyne spider (Arachnida, Araneae, Tetrablemmidae) indicates internal fertilization and full female control over transferred sperm

The female genital organs of the tetrablemmid Indicoblemma lannaianum are astonishingly complex. The copulatory orifice lies anterior to the opening of the uterus externus and leads into a narrow insertion duct that ends in a genital cavity. The genital cavity continues laterally in paired tube-like copulatory ducts, which lead into paired, large, sac-like receptacula. Each receptaculum has a sclerotized pore plate with associated gland cells. Paired small fertilization ducts originate in the receptacula and take their curved course inside the copulatory ducts. The fertilization ducts end in slit-like openings in the sclerotized posterior walls of the copulatory ducts. Huge masses of secretions forming large balls are detectable in the female receptacula. An important function of these secretory balls seems to be the encapsulation of spermatozoa in discrete packages in order to avoid the mixing of sperm from different males. In this way, sperm competition may be completely prevented or at least severely limited. Females seem to have full control over transferred sperm and be able to express preference for spermatozoa of certain males. The lumen of the sperm containing secretory balls is connected with the fertilization duct. Activated spermatozoa are only found in the uterus internus of females, which is an indication of internal fertilization. The sperm cells in the uterus internus are characterized by an extensive cytoplasm and an elongated, cone-shaped nucleus. The male genital system of I. lannaianum consists of thick testes and thin convoluted vasa deferentia that open into the wide ductus ejaculatorius. The voluminous globular palpal bulb is filled with seminal fluid consisting of a globular secretion in which only a few spermatozoa are embedded. The spermatozoa are encapsulated by a sheath produced in the genital system. The secretions in females may at least partly consist of male secretions that could be involved in the building of the secretory balls or play a role in sperm activation. The male secretions could also afford nutriments to the spermatozoa.

Erection induced by Tx2-6 toxin of Phoneutria nigriventer spider: expression profile of genes in the nitric oxide pathway of penile tissue of mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the developing male Wistar(Han) rat I: no decrease in epididymal sperm count after a single acute dose

It has been reported that fetal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes defects in the male reproductive system of the rat. We set out to replicate and extend these effects using a robust experimental design. Groups of 75 (control vehicle) or 55 (50, 200 or 1000 ng of TCDD kg-1 bodyweight) female Wistar(Han) rats were exposed to TCDD on Gestational Day (GD) 15, then allowed to litter. The high dose group dams showed no sustained weight loss compared to control, but four animals had total litter loss. Pups in the high dose group showed reduced body weight up till day 21, and pups in the medium dose group showed reduced body weight in the first week post partum. Balano-preputial separation (BPS) was significantly delayed in the high dose group male offspring. There were no significant effects of treatment when the offspring were subjected to a functional observational battery, or mated with females to assess reproductive capability. 25 males per group were killed on post natal day (PND) 70, and ~60 animals per group (~30 for the high dose group) on PND120 to assess seminology and other endpoints. At PND120, the two highest dose groups showed a statistically significant elevation of sperm counts, compared to control; however, this effect was small (~30%), within the normal range of sperm counts for this strain of rat, was not reflected in testicular spermatid counts nor PND70 data, and is therefore postulated to have no biological significance. Although there was an increase in the proportion of abnormal sperm at PND70, seminology parameters were otherwise unremarkable. Testis weights in the high dose group were slightly decreased at PND 70 and 120, and at PND120, brain weights were decreased in the high dose group, liver to body weight ratios were increased for all three dose groups, with an increase in inflammatory cell foci in the epididymis in the high dose group. These data show that TCDD is a potent developmental toxin after exposure of the developing fetus, but that acute developmental exposure to TCDD on GD15 caused no decrease in sperm counts.

Toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the developing male Wistar(Han) rat II: chronic dosing causes developmental delay

We have investigated whether fetal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes defects in the male reproductive system of the rat, using chronically exposed rats to ensure continuous exposure of the fetus. 5-6 week old rats were exposed to control diet, or diet containing TCDD, to attain an average dose of 2.4, 8 and 46 ng TCDD kg-1 day-1 for twelve weeks, whereupon the rats were mated, and allowed to litter; rats were switched to control diet after parturition. Male offspring were allowed to develop until kills on PND70 (25 per group), or PND120 (all remaining animals). Offspring from the high dose group showed an increase in total litter loss, and the number of animals alive on post-natal day (PND) 4 in the high dose group was ~26% less than control. The high and medium dose offspring showed decreased weights at various ages. Balano-preputial separation was significantly delayed in all three dose groups, compared to control. There were no significant effects of maternal treatment when the offspring were subjected to a functional observational battery, or learning tests, with the exception that the high dose group showed a deficit in motor activity. 20 rats per group were mated to females, and there were no significant effects of maternal treatment on the fertility of these rats, nor on the F1 or F2 sex ratio. Sperm parameters at PND70 and 120 showed no significant effect of maternal treatment, with the exception that there was an increase in the proportion of abnormal sperm in the high dose group at PND70; this is associated with the developmental delay in puberty in this dose group. There were no remarkable findings of maternal treatment on organ weights, with the exception that testis weights were reduced by ~10% at PND70 (but not PND120), and although the experiment was sufficiently powered to detect small changes, ventral prostate weight was not reduced. There were no significant effects of maternal treatment upon histopathological comparison of high dose and control group organs. These data confirm that developmental exposure to TCDD shows no potent effect on adult sperm parameters or accessory sexual organs, but show that delay in BPS occurs after exposure to low doses of TCDD, and this is dependent upon whether TCDD is administered acutely or chronically.