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The adverse effects of bisphenol ‘A’ on some reproductive organs of the male albino rat: a light and electron microscopic study

El-Bassouny, Dalia R.; Hindawy, Mohamed

The Egyptian Journal of Histology: September 2013 - Volume 36 - Issue 3 - p 564–578
doi: 10.1097/01.EHX.0000431787.59638.92
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Background Bisphenol A (BPA) is a xenoestrogen (environmental estrogens) used in the production of polycarbonate plastics and epoxy resins that line food and beverage cans. Modernization of the Arabian Gulf region has resulted in the wide consumption of readymade foods that are packed in plastic containers and cans. Consequently, the majority of humans, particularly infants and children, are being continuously exposed to it.

Aim of work The objective of the present study was to examine the effect of exposure to BPA on the testis, epididymis, prostate, and penile corpora of adult albino rat.

Materials and methods One, 4, and 8 weeks following a subcutaneous injection of 150 µg BPA/kg body weight into adult albino rats every other day for 12 days, the histopathological changes induced in the testis, epididymis, prostate, and penile corpora were detected using both light and transmission electron microscopic techniques.

Results In BPA-treated animals, seminiferous tubules showed a decreased thickness of germinal epithelium with vacuolar degeneration and increased apoptotic cells. Sperm were hardly seen till the eighth week, when spermatogenesis was regained, but spermatids and mature sperm still had residual malformations. The rough endoplasmic reticulum cisternae of prostatic parenchyma appeared distended with a homogeneous content whereas most of the secretory vesicles were empty. In the penile corpora of BPA-treated groups, both tunical thickness and trabecular smooth muscle content were increased with consequent narrowing of sinusoidal spaces.

Conclusion These results suggest that BPA inhibits spermatogenesis, increases the ratio of sperm anomalies, and has a potential harmful effect on erectile function, which raises an alarm to the harmful effects of environmental contaminants that might cause subfertility or infertility.

Department of Anatomy and Histology, Faculty of Medicine, Qassim University, Kingdom of Saudi Arabia and Department of Histology and Cell Biology, Faculty of Medicine, Mansoura University, Egypt

Correspondence to Dalia R. El-Bassouny, Department of Anatomy and Histology, Faculty of Medicine, Qassim University, Kingdom of Saudi Arabia Tel: 00966533684586; e-mail: refat_dalia@hotmail.com

Received November 22, 2012

Accepted January 15, 2013

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Introduction

Xenoestrogens are a diverse group of chemicals that may have adverse effects on both human and wildlife reproductive health performance 1,2. Bisphenol A (BPA) is a high-volume synthetic monomer used in the production of polycarbonate plastics and epoxy resins that line numerous common household and consumer products 3. Although polymeric forms are relatively stable, water-soluble BPA monomers are known to act as a xenoestrogen, they are released when exposed to heat, acidic pH, after repeated use and over time, leaching into consumable liquids and foods and bioaccumulating in environments worldwide 4–6. Consequently, the majority of humans have detectable levels of BPA in their sera 7, with the highest levels found in infants and children 8. As BPA is rapidly metabolized and excreted with a half-life of less than 6 h, this indicates that humans are being exposed to BPA continuously 9.

Monomeric BPA binds to estrogen receptors (ERα and ERβ), induces progesterone receptors, and promotes MCF-7 breast cancer cell proliferation 10. Although affinity for nuclear ERs is low relative to natural estradiol 11, BPA has activational capacity equivalent to estradiol for membrane-associated ERs 2,12. Although the topic remains highly controversial, there is a growing body of evidence that BPA has adverse effects on multiple hormone responsive tissues at environmentally relevant doses 13.

Neonatal estrogenization of rodents is being used as a model to evaluate the role of exogenous and endogenous estrogens as a predisposing factor for prostatic diseases later in life 14,15. The administration of BPA to ovariectomized rats induced cell proliferation in the epithelia of the uterus and vagina and hyperprolactinemia 16. Although BPA injection in male rats affected the male reproductive system including androgen receptors, sex hormone levels, reproductive organs 17, and even sexual behavior 18, some researchers have not observed any effects of BPA in their animal studies 19. However, these findings of a lack of an observed BPA effect have been challenged recently by a group of scientists from more than 30 academic and research institutes 20.

BPA has been considered a highly suspect human endocrine disruptor, likely affecting both male and female reproductive systems. However, the evidence of such effects from epidemiological studies of the human population are lacking as noted by two US government panels convened by the National Toxicology Program and the National Institute of Environmental Health and Safety 21. Largely on the basis of findings from animal studies, these two panels reached somewhat different conclusions on the potential effect of BPA as a human endocrine disruptor, leading to a widely publicized controversy that was further intensified after the recent tentative decision on BPA safety by the Food and Drug Administration in the USA was subsequently rebutted by its own science board 22. In the Arabian Gulf region, the widespread dependence on readymade food and beverages that are packed in plastic containers and cans may raise concerns in terms of the adverse effects of synthetic monomeric materials such as BPA at the level of the male genital system. The objective of the present study was to examine the histopathological effects of exposure to BPA on the testis, epididymis, prostate and penile corpora of adult albino rat.

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Materials and methods

In the present study, all procedures involving animals were approved by the Qassim University, College of Medicine Animal Research Policies Committee. Male albino rats (12–18 weeks old) were injected subcutaneously with 150 µg/kg of BPA dissolved in olive oil (Sasso, Minerva, Italy) every other day for 12 days. One week (group I, N=15), 4 weeks (group II, N=15), and 8 weeks (group III, N=15) after the administration of BPA (Sigma-Aldrich, St. Louis, USA), the animals were sacrificed. The control animals (group IV, N=15) received the same amount of olive oil for the same period of time as the experimental group. All animals were kept in cages, with food and tap water ad libitum.

On the assigned day of sacrifice, the treated animals and five from the control group were weighed alive and then subjected to perfusion fixation with 3% glutaraldehyde in 0.1 phosphate buffer (pH 7.4) after anesthesia of diethyl ether inhalation. The testes were removed and weighed and selected specimens from the testis, epididymis, and ventral prostate were collected under an Olympus SZX7 Microscope (Olympus Optical Co., Tokyo, Japan) and then immersed in the same fixative for 24 h at 4°C. After postfixation in 1.0 OsO4 in 0.1 mol/l phosphate buffer for 2 h at room temperature, the tissue specimens were subjected to dehydration in graded ethanol and substitution with propylene oxide to be embedded in an Epon 812–resin mixture (Spa; USA). Semithin sections (0.5-µm thick) were cut by an ultramicrotome (Leica EM UC7; Leica, Berlin, Germany) and stained with toluidine blue; then, ultrathin sections (80-nm thick) were sectioned and counterstained with uranyl acetate and lead citrate. Sections were examined under light (Leica DMD108; Leica) and transmission electron (JTEM 1010; JEOL, Tokoyo, Japan) microscopes.

Each penis was cut grossly into cross-sectioned specimens that were fixed in 10% neutral-buffered formalin, and then processed for paraffin sectioning at 4 µm thickness, placed on glass slides, and stained with H&E and Masson’s trichrome. Tunical thickness was measured at three levels of the distal, midshaft, and proximal part of the penis. Image analysis of the smooth muscle fibers and of the cavernosal space surface areas was carried out using a CAS-200 Image Analyzer (Becton Dickinson Co., 1 Becton Dr, Franklin Lakes, USA). The percentage of area of smooth muscle fibers per standard square area at five different fields and the relative surface area of the cavernosal spaces in relation to the entire specimen were measured under the same magnification for two sections in each case. The mean values were used for each animal.

The results of control and treated animals were subjected to Student’s t-test; a P value of less than 0.05 was considered as significant.

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Results

Body weight

The mean body weight of the vehicle-treated control animals was 177.05±6.49 g. Although there was a mild increase in the body weight during the 8-week recovery period, the change was statistically insignificant (Table 1).

Table 1

Table 1

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Testis

Weight of testes

The mean weights of testes in BPA-treated rats did not show significant differences throughout the study period. All values were within the control limits (Table 1).

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Light microscopy

In semithin sections of testes of control animals, the basal layers of the spermatogenic epithelium are packed with spermatogonia, followed by succeeding layers of germ cells representing various stages of spermatogenesis (Fig. 1a). One week after the experiment, the germinal epithelium in almost all the seminiferous tubules suffered extensive degenerative vacuolization; round spermatids were exfoliated and lost, the density of primary spermatocytes and spermatogonia deteriorated markedly, and spermatozoa disappeared. Other testicular tissues including intertubular tissue and myoid cells were apparently preserved (Fig. 1b). After 4 weeks, despite appearing low, the testicular germinal epithelium gained some recovery; large vacuoles were no longer observed (Fig. 1c). Sperm were seldom seen till the eighth week after the cessation of BPA administration, when the germinal epithelium became more or less identical to that of the control group; it regained its full thickness, with the appearance of signs indicative of full spermatogenesis. However, spermatogonia formed a discontinuous basal layer compared with the control samples (Fig. 1d).

Figure 1

Figure 1

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Electron microscopy

In samples taken 1 and 4 weeks after the administration of BPA, the deteriorating effects were detected in all spermatogenic cells, particularly spermatids. Severely deformed spermatogonia and primary spermatocytes that contained large nuclei with clumped chromatin and cytoplasmic dense bodies were commonly observed. The thickened basement membrane was unusually folded. However, the integrity of the Sertoli cell population was un-debatable; their indented nuclei contained prominent nucleoli and finely granular chromatin and their cytoplasmic ultrastructure and intercellular bridges were somewhat still preserved (Fig. 2). Finally, during the eighth week after BPA withdrawal, some minor disconnecting areas were still observed among spermatogenic cells, with a prevalence of microvesicles at the periphery of the cytoplasm. Elongated spermatids and highly apoptotic bodies were desquamated into the lumen (Fig. 3).

Figure 2

Figure 2

Figure 3

Figure 3

A primary characteristic of Sertoli cells was their large indented nuclei, which contained finely granular chromatin. Although cytoplasmic structural integrity was maximally perfect in control specimens (Fig. 4a), it was surprisingly reasonable in all experimental groups. Apart from the diversity of the secretory granule content, the ultrastructural adverse effects of BPA on the Sertoli cell population were insignificant in all groups (Fig. 4b).

Figure 4

Figure 4

Primary spermatocytes were the most common adluminal cells encountered in seminiferous tubules of samples taken early after BPA withdrawal. In samples taken after 8 weeks, these cells appeared somewhat regenerated; their granular cytoplasm showed many vital organelles including mitochondria, microtubules, microfilaments, and proacrosomal vesicles (Fig. 5).

Figure 5

Figure 5

Despite regaining the structural and functional characteristics of the seminiferous tubules 8 weeks after BPA injection, metamorphosis processes remained obviously affected. Low-power electron micrographs showed that round spermatids appeared normal (Fig. 3). However, under high powers of magnification, many ultrastructural defects that were caused by metamorphosis were discovered; the acrosomal caps sometimes appeared thin and the marginal rings of the exoplaxome were aplated or caudally displaced to the posterior pole of the nucleus. The postacrosomal sheath was not formed at all and when formed, it seemed defective or even extended caudally over the cytoplasmic part. The ectopic ectoplasmic specialization was always remained. Apoptotic bodies containing masses of diverse osmiophilic densities and sizes appeared within some round spermatids and inside the lumen of the seminiferous tubule. Specialization of the caudal part of the spermatid also had some anomalies; the basal plate and fossa were absent and the basal fossa sometimes appeared striated. In addition, mitochondria were rarely detected (Figs. 6 and 7).

Figure 6

Figure 6

Figure 7

Figure 7

The morphological abnormalities that were encountered during metamorphosis of spermatids were probably reflected on the ultrastructure of maturing sperm. The cytoplasm also remained redundant over the tail region and mitochondria were rarely seen. Sections in tails showed that the outer fibers were unequal in size or reduced in number (Fig. 8).

Figure 8

Figure 8

One week after BPA withdrawal, Leydig cells appeared unhealthy; they had a dense cytoplasmic matrix containing vague osmiophilic organelles and lipid droplets were not detected. The nuclei appeared oval with clumped chromatin content. After 4 weeks, Leydig cells showed some signs of recovery; their nuclei became pale, with the reappearance of structured cytoplasm showing well-developed Golgi saccules and cytoplasmic vesicles indicating regaining of secretory activity (Fig. 9).

Figure 9

Figure 9

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Epididymis

The notable feature of the epididymis was the presence of very long microvilli that covered the luminal surface of its lining pseudostratified columnar epithelium (Fig. 10). Just underneath the surface, the terminal web appeared as a band of filaments and many large secretory vesicles occupied the apical part of the cytoplasm (Fig. 10a). Under high power, the cytoplasm of these epithelial cells showed considerable rough endoplasmic reticulum cisternae and prominent Golgi regions. The contents of secretory vesicles appeared homogeneous, but sometimes they were condensed into small dense spheres (Fig. 10b). Several sections along the different levels of sperm were observed inside the lumen; they showed normal structure (Fig. 10c). Examination of epididymis in experimental groups till the eighth week after BPA cessation showed an insignificant adverse structural effect; however, paucity or deficiency of stored luminal sperm was a common finding (Fig. 10d).

Figure 10

Figure 10

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Prostate

Electron micrographs of prostate tissue of the control group showed that the glandular acini were lined with pseudostratified columnar cells with highly indented euchromatinic nuclei that occupied the largest part of the cell and the cytoplasm was very rich in rough endoplasmic reticulum profiles whereas Golgi zones could be observed clearly. Abundant round to oval secretory vesicles were observed at different locations inside the cells; the content of these vesicles appeared homogeneous, with moderate electron density. The basement membrane of the glandular acini separates them from the surrounding fibromuscular stroma. The acinar lumen appears very narrow (Fig. 11a). After BPA administration till the eighth week (Figs. 11b, c, and d), the rough endoplasmic reticulum cisternae appeared highly dilated and contained a homogeneous content of moderate electron density. Most of the secretory vesicles appeared to be empty, with the appearance of prostatic concretions in the lumen till the eighth week, where most of the secretory vesicles regained their content similar to that in the control group (Fig. 11).

Figure 11

Figure 11

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Penis

In the penis of control rats, the amount of smooth muscle fibers was 31.2% of the specimen and tunica albuginea was 0.30–0.42 mm in thickness (Table 2), with no evidence of abnormal fibrosis or smooth muscle proliferation (Fig. 12). In specimens taken 1 week after BPA withdrawal, the amount of smooth muscle fibers and tunical thickness were found to be slightly higher than the control values, but there was no statistical significance (P>0.05) (Table 2). In BPA-treated animals, the apparent proliferation of smooth muscle fibers inside the trabeculae compressed the sinusoidal spaces into anastomosing tunnels that were significantly narrower (P>0.05) (Table 2) compared with those observed in the control specimen under the same power of magnification. The gained thickness of tunica albuginea was derived from the marked increase in collagenous fibers, which appeared paler than smooth muscle fibers in sections stained with Masson’s trichrome stain. The numbers of smooth muscle fibers were significantly increased to 71.3 and 82.3%, respectively, in specimens taken 4 and 8 weeks after BPA withdrawal compared with the control group (P<0.05) (Table 2).

Table 2

Table 2

Figure 12

Figure 12

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Discussion

BPA is an endocrine-disrupting chemical that can induce a variety of adverse effects in mammals and other vertebrates and invertebrates 23. Worldwide, 50–80 million individuals are infertile, an estimate that is likely to increase considerably in the future. Several factors are known to underlie male infertility; exposure to environmental toxicants is one of these factors. Although it is not yet completely understood why the testis is so vulnerable to damage by environmental toxicants such as BPA, it is clear that toxicants affect many, if not all, mammalian organs in some adverse way 24.

In the present study, BPA was administered through a subcutaneous injection to adult rats. It is currently believed that the majority of BPA intake in humans occurs through oral ingestion and is thus subjected to hepatic first-pass metabolism, where ∼99% of orally ingested BPA by adults is rapidly metabolized to an inactive form before entry into the general circulation 25,26. In contrast, BPA delivery by a subcutaneous injection will enter the circulation before liver metabolization; thus, initial exposure levels of free BPA by this route might be markedly higher than current human circulating levels. This must be taken into consideration when evaluating BPA toxicity and its relevance to human health 27.

In this work, there was a statistically insignificant increase in body weight during the 8-week recovery period; also, the mean weights of testes in BPA-treated rats were insignificantly decreased throughout the study period. These results were in accordance with others who observed that successive intraperitoneal administration of BPA to adolescent male mice and rats 28,29 at a dose of 20 mg/kg/day for 4 weeks decreased the prostate and seminal vesicle weights (but not testis or epididymis weights) and also decreased serum testosterone and both liver and kidney weights. However, a significant decrease in testicular and epididymal weight was also reported to occur in adult male Wistar rats exposed orally to 0.2, 2, and 20 µg/kg/day of BPA for 45 days, whereas an increase in ventral prostate weight occurred at all doses 30,31.

In samples of testis taken 1 and 4 weeks after the withdrawal of BPA, there was extensive degeneration in all spermatogenic lineage, particularly spermatids. Finally, on the eighth week after BPA withdrawal, some minor disconnecting areas were still observed among the spermatogenic cells; this might indicate disconnected junctional complexes between the cells. If adhesion was to be compromised by an environmental toxicant, for instance, germ cells would slough from the seminiferous epithelium, spermatogenesis would be arrested, and subfertility or infertility may result 24. The prevalence of microvesicles at the periphery of the cytoplasm possibly indicated premature acrosomal cap formation because of slow spermatogenesis that might be caused by the severely deformed spermatogonia and primary spermatocytes 25.

Despite relative regaining of the normal morphological characteristics of the seminiferous tubules 8 weeks after BPA injection, residual structural defects in metamorphosis including acrosomal caps, the marginal rings of the exoplaxome, the postacrosomal sheath, and the ectopic ectoplasmic specialization remained; specialization of the caudal part of the spermatid also showed some anomalies. Similar deformities were observed at a dose of 20 µg/kg body weight of BPA by a subcutaneous injection to adult mice and Wistar rats for 6 days 32. Some authors 33,34 have proposed the presence of an AAM (Actin in the ectoplasmic specialization between the Sertoli cell and spermatids, Acroplaxome with marginal rings, a Manchette with perinuclear rings) complex that is responsible for nuclear shaping. Both the AAM complex and the postacrosomal sheath became affected in the spermatids under BPA treatment 32. The postacrosomal sheath serves as a cytoskeletal element to the nucleus and also triggers molecules for oocyte activation at the time of fertilization 35.

Spermatogenesis is a complex and stepwise cellular process that results in the production of ∼25 000 sperm each minute in healthy adult males, and it takes place within seminiferous tubules in the mammalian testis under the strict regulation of testosterone, follicle stimulating hormone, luteinizing hormone, and estradiol 17β 36.

In the current work, the morphological abnormalities that were detected during metamorphosis of spermatids were probably reflected on the ultrastructure of maturing sperm. These abnormalities involved cytoplasmic redundancy, mitochondrial content, outer fiber size and number, in addition to paucity of sperm stored in the epididymis. A decrease in daily sperm production and fertility in adult male rats was reported at oral doses of BPA between 20 and 200 000 µg/kg/day, and the maximum suppression of sperm production occurred at 20 µg/kg/day. At doses below 20 µg/kg/day, daily sperm production was not significantly different from that of the controls 37. It was suggested that there is a subpopulation of cells that are impacted by BPA and that a ∼40% decrease in daily sperm production is the maximum that occurs, irrespective of the dose of BPA administered above 20 µg/kg/day. Similarly, some data reported that after prenatal exposure to ethinylestradiol, maximum suppression of daily sperm production occurred at 2 ng/kg/day, with no further suppression occurring at higher doses 38. In addition, an injection (subcutaneous) of BPA (50 µg/animal, about 15–20 mg/kg/day) for the first 5 days after birth of mice resulted in a decrease in the percentage of moving sperm, an increase in the incidence of malformed sperm, and an increase in the number of ERα-positive cells in the epididymis of SHN strain mice at 10 weeks of age 39.

The ultrastructural adverse effects of BPA on the Sertoli cell population were insignificant and the intercellular cytoplasmic connecting bridges among them were present in all groups; this might indicate spared blood–testis barrier (BTB). Similar findings were reported by others 32,40. It was reported that the BTB is one of the tightest blood–tissue barriers in the mammalian body. It divides the seminiferous epithelium into basal and apical compartments. Meiosis I and II, spermiogenesis, and spermiation all occur in a specialized microenvironment behind the BTB in the apical compartment, but spermatogonial renewal and differentiation and cell cycle progression up to the preleptotene spermatocyte stage occur outside of the BTB in the basal compartment of the epithelium. The BTB is not a static ultrastructure. Instead, it undergoes extensive restructuring during the seminiferous epithelial cycle of spermatogenesis to allow the transit of preleptotene spermatocytes at the BTB. Recent findings have reported on the molecular mechanisms by which environmental toxicants including BPA induce testicular injury by their initial actions at the BTB to elicit subsequent damage to germ-cell adhesion, thereby leading to germ-cell loss, reduced sperm count, and male infertility or subfertility 41.

One week after BPA withdrawal, Leydig cells appeared unhealthy but after 4 weeks, these cells showed some signs of recovery. It was reported that 200 mg/kg BPA and 100 g/kg E2 significantly decreased Leydig cell numbers in the rat testis and BPA directly affected not only the Leydig cells but also the pituitary gland, but the former might be impaired at lower exposure concentrations than the latter 42. In addition, plasma-free testosterone levels were markedly decreased following 8 weeks of 12 mg/kg/day of BPA treatment of adult male mice compared with the control group, and abnormal multinucleated giant cells were found morphologically in seminiferous tubules in the testis following an 8-week BPA treatment at 120 µg/kg/day 43.

In the current work, much apoptotic bodies had desquamated into the lumen of the seminiferous tubules. It was reported that spermatogenesis is highly influenced by external stimuli, such as drugs, radiation, reproductive and somatic pathologies, seasonal breeding, temperature, and environmental pollutants including BPA, which increase the constitutive levels of apoptosis in germ cells 44. Several studies have suggested that increased germ cell apoptosis during spermatogenesis might explain decreased sperm production in patients with oligospermia and azoospermia 45.

After the withdrawal of BPA till the eighth week, the rough endoplasmic reticulum cisternae of prostatic parenchyma appeared distended with a homogeneous content whereas most of the secretory vesicles were empty; this might point to a BPA-induced metabolic error that probably resulted in delayed secretion from the acini in addition to the formation of prostatic concretions as seen in our results. Similarly, dilated cisternae of the endoplasmic reticulum, many protein-filled vacuoles, and large vacuoles containing altered cell organelles were suggestive of apoptosis induced by diabetes in prostate 46.

A growing body of evidence suggests that adult estrogen exposures can be carcinogenic to the prostate gland 47. Elevated estrogen levels during fetal life may affect the expression of genes involved in the morphogenesis of the gland and, in turn, result in persistent changes in the histological architecture of the gland 48. Alterations in the stromal compartment of prostatic tumors may enhance the invasive and/or malignant potential of the nascent epithelial tumor 49.

Penile erection depends on the balance and integration of neurotransmitters, vasoactive substances, endocrine factors, and tissue fibroelastic properties. It can be assumed that antiandrogen, estrogen, or xenoestrogen may affect erectile function 50. The erectile tissue of the penis is composed of elastic fibers, collagen fibers, smooth muscles, arteries, and veins, which are surrounded by a collagenous tunica albuginea. Trabecular smooth muscle tone has been considered as a major contributing factor to trabecular smooth muscle contractility; relaxation of the smooth muscle of the corpus cavernosum is crucial for the development of penile erection 51. For erection to occur, the penile arteries and sinusoids must be dilated, thus increasing the blood flow into the penis, and the distended sinusoids compress the venules against the tunica albuginea 52. In BPA-treated animals, the numbers of smooth muscle fibers were significantly increased within the trabeculae, thus compressing the sinusoidal spaces into anastomosing tunnels that were significantly narrowed, which might decrease the arterial blood flow and thereby affect penile erection. In addition, the thickness of tunica albuginea gained as a result of the marked increase of collagenous fibers might limit the expandability of the tunica albuginea and restricts the engorgement of the cavernosum, which might prevent penile enlargement and erection. Penile tunica albuginea represents an important part of the fibrous corpora cavernosa skeleton; its collagenous fibers, accompanied by elastic networks, are arranged in an outer, mainly longitudinal, and an inner circular layer 53. These fibers allow penile elongation during tumescence and an increase in girth during erection while providing adequate resilience for a rapid return to the relaxed nonerect state at detumescence 54,55. Loss of corporeal elasticity by decreased vascularity with a consequent increased ratio of cavernosal smooth muscle content and thickening of tunica albuginea might be a result of the xenoestrogenic effect of BPA, which adversely affects erectile homodynamic. Also, it was reported that the estrogen receptor pathway, the androgen receptor pathway, or both mediate estrogen-induced developmental penile disorders 56. Chronic exposure of low-dose BPA may result in erectile dysfunction in aging males or may exacerbate the aging process with consequent erectile dysfunction 50.

It is concluded that BPA inhibits spermatogenesis, increases the ratio of sperm anomalies, and exerts a potential harmful effect on erectile function. Some of the exposure to environmental toxicants can be controlled by personal choices, such as deciding not to smoke and choosing glassware over polycarbonate plastic ware; however, these choices cannot completely protect an individual from the harmful effects of environmental contaminants that might be the cause of subfertility or infertility.

Further studies on the effects of different doses of BPA on the physiology, types of collagen, and receptors in human erectile tissue should be carried out to identify the more precise effect of BPA on human erectile function.

Table

Table

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Acknowledgements

The authors thank Qassim University for supporting this study (grant Sabic number SR-S-011-18).

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Conflicts of interest

There is no conflict of interest to declare.

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Keywords:

bisphenol A; penile corpora; rat; testis; ultrastructure

© 2013 The Egyptian Journal of Histology