Role of serotonin, estrogen, and TNF-α in the paroxetine-impaired steroidogenesis and testicular macrophages polarization

BACKGROUND

Paroxetine, a selective serotonin reuptake inhibitor (SSRI) antidepressant, has caused male sexual dysfunction; however, the paroxetine mechanisms of action in testes are still unclear.

OBJECTIVES

Paroxetine serotonergic effects in testes were evaluated, focusing on steroidogenesis and the correlation between macrophages population and possible TNF-α-derived oxidative stress. We also verified whether the changes are reversible following treatment interruption.

MATERIALS AND METHODS

Adult rats received paroxetine (PG35 and PG65) or tap water (CG) for 35 days. PG65 was maintained without treatment for 30 more days. Intratesticular testosterone (IT), nitrite, and malondialdehyde concentrations were measured. To confirm serotonergic and estrogenic effects, Htr1b and Esr1 expressions were analyzed. The daily sperm production (DSP), frequency of abnormal seminiferous tubules (ST), SC number, ST area, and Leydig cells nuclear area (LCnu) were evaluated. TUNEL+ germ cells, M1 (CD68+ ), and M2 (Perls+ ) macrophages were quantified. 17β-HSD7, CYP19A1, NDRG2, oxytocin, TNF-α, and iNOS were evaluated by immunoreactions. Oxytocin and NDRG2 protein levels as well as Tnfa mRNA expression were also analyzed.

RESULTS

The Htr1b downregulation in testes confirmed the paroxetine serotonergic effect. The testicular sections showed abnormal ST frequency, ST atrophy and reduction of DSP, LCnu, SC number and Perls+ macrophages. TUNEL+ germ cells and LC were associated with strong NDRG2 immunoexpression. Paroxetine reduced IT levels and 17β-HSD7 immunoexpression in parallel to increased CYP19A1, oxytocin, TNF-α and iNOS. Esr1 and Tnfa overexpression and increased number of CD68+ macrophages were also observed together with high nitrite and malondialdehyde levels. Most parameters were not recovered in PG65.

CONCLUSIONS

Paroxetine serotonergic effect impairs LC steroidogenesis, via aromatization, increasing estrogen/testosterone ratio, which in turn upregulate NDRG2, promoting apoptosis, and impairing sperm production. Serotonin-estrogen pathways may be responsible for M2/M1 polarization, Tnfa upregulation, and induction of oxidative stress. The unrecovered testicular changes after treatment discontinuation are due to persistent paroxetine serotonin/estrogen effects.

Long-term exposure to cimetidine induced gonado-toxicity in male rats: Modulating role of Ocimum gratissimum

BACKGROUND

Available evidence suggests that cimetidine is a reproductive toxicant that induces sexual and testicular dysfunction. Ocimum gratissimum (OG) is globally consumed for medicinal and nutritional purposes. To determine the modulating role of aqueous leaf extract of Ocimum gratissimum on cimetidine-induced gonado-toxicity, sexually mature male rats were randomized into four groups of six (n=6) rats each. Group A: control given 2ml distilled water. Group B received 500mg/kg body weight (bwt) of OG extract, Group C received 50mg/kg bwt cimetidine, and group D received 50mg/kg bwt of cimetidine+500mg/kg bwt OG extract once daily for 8 weeks via gastric gavage. Parameters tested include sperm parameters, testosterone (TT), luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin, testicular alkaline phosphatase (ALP), acid phosphatase (ACP), lactate dehydrogenase (LDH), protein, cholesterol, glycogen, sexual behavioural parameters, and testicular histology.

RESULTS

There were depletions in the seminiferous epithelium, decreased sperm quality, TT, LH, and FSH, testicular enzymes, protein, cholesterol, glycogen, and sexual behaviour increase in animals treated with cimetidine only compared to control. OG restored and improved sexual behaviour and libido as evident from increased frequencies of mount, intromission, ejaculation, and ejaculatory latency. Mount latencies, intromission, post-ejaculation, and prolactin were significantly decreased. The significantly decreased testicular activities of ALP, ACP, LDH and protein, cholesterol, glycogen concentrations, TT, LH and FSH were increased by OG administration.

CONCLUSION

Ocimum gratissimum attenuated the deleterious effects of cimetidine on the testis, protected the seminiferous epithelium, restored, and boosted sexual competence, and promoted spermatogenesis.

Vitamin B12 ameliorate Tramadol-induced oxidative stress, endocrine imbalance, apoptosis and NO/iNOS/NF-κB expression in Sprague Dawley rats through regulatory mechanism in the pituitary-gonadal axis

This study aimed at the effect of vitamin B₁₂ (VB₁₂) on tramadol (TRM) induced pituitary-gonadal Axis toxicity. Thirty-two (32) adult male rats were randomized into four groups of eight (n = 8) rats each. Group A served as control was given 1 mL normal saline, group B received 50 mg /kg bwt TRM, group C received 0.5 mg/kg bwt VB₁₂ and group D received 50 mg /kg bwt TRM and 0.5 mg/kg bwt VB₁₂ through gastric gavage daily for 8 weeks. Parameters tested include sperm parameter, male reproductive hormone, testicular histology, glucose, lactate dehydrogenase (LDH), acid phosphate (ACP), and alkaline phosphate (ALP) activity, steroidogenic protein, cytochrome P450 A1, nitric oxide (NO), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), nuclear factor- kappa B (NF-κB), oxidative and antioxidant makers. Tramadol significantly decreases sperm quality, hormone, steroidogenic protein, cytochrome P450 A1, ACP, ALP, and increases glucose, LDH, oxidative stress, mtTFA, and UCP2, p53 expression, NO, iNOS, NF-κB, IL-1β, IL-6, TNF-α, and caspase-3 activity. Degenerative alterations of the testes' and pituitary architecture and perturbation of spermatogenesis were observed in TRM-treated rats. The intervention of VB₁₂ downregulated testicular oxidative stress, inflammatory markers, glucose, lactate, LDH, p53, caspase-3, mtTFA, and UCP2. And upregulate antioxidant, sperm quality, hormone, and spermatogenic cells. Vitamin B₁₂ exhibited mitigation against TRM-induced testicular dysfunction via its antioxidant, anti-inflammatory and anti-apoptotic effects.

Effect of Nandrolone decanoate induced-oxidative stress on rat testes, prostate, and seminal vesicle: Biochemical, morphometric and histopathological studies

Nandrolone decanoate (Nd) is a highly abused androgenic-anabolic steroid among body builders. Even though it has weak androgenic effects, its prolonged use may have harmful impact on male reproductive system which needs to be evaluated. This study aimed to reinvestigate its possible oxidative stress induced alteration on male rat reproductive system. Twenty-eight male rats were divided into two groups. Nd treated group (n = 18) injected intramuscular with 10 mg/kg body weight once a week for four weeks. While, the control group (n = 10) was injected with physiologic saline by the same route for four weeks. Body weight was recorded for all rats and after animal dissection weight of testes, prostate and seminal vesicles were also recorded. The results showed that the average testicular weight was decreased in treated group compared to the control. The average weights of the prostate and seminal vesicles were increased compared to the control. Morphometric study revealed that in Nd treated group, there was a decrease in the width of seminiferous tubules and the height of spermatogenic cell layer compared to the control. Testicular degeneration was expressed by presence of spermatid giant cells, vacuolation, and degenerated spermatozoa. Tunnel technique showed scattered positive reaction among the spermatogenic cell layers and interstitial cells. Severe alterations of the prostate were expressed by benign prostate hyperplasia and retained secretions. Lipid peroxidation products (malonaldehyde concentration as ng/g of testicular tissue) were increased in treated group compared to the control and suggested the occurrence of oxidative damage. Nd induced severe alterations in the male genital organs were resulted from oxidative stress. It is concluded that the male genital organs are highly sensitive to the anabolic steroids and there is a high extent of reproductive risk associated with the use of AASs.

Exposure to benzo(a)pyrene from juvenile period to peripubertal impairs male reproductive parameters in adult rats

Benzo(a)pyrene (BaP) is a persistent organic pollutant and endocrine disruptor that can compromise the steroidogenesis process by interacting with the StAR protein, causing adverse effects on male reproduction. However, consequences of prepubertal BaP exposure and its impacts on adult life are yet unknown. This study investigated the effects of BaP exposure from the juvenile period to peripubertal on reproductive parameters in adult male rats. Males were exposed to 0; 0.1; 1 or 10 μg/kg/day of BaP from post-natal (PND) 23 to PND 53 (by gavage). The lowest dose of BaP was able to compromise the male copulatory behavior, as evidenced by the delay in the first mount, intromission and ejaculation. Furthermore, BaP-treated groups showed lower sperm quality (disrupted motility and morphology) and quantity, reduced relative weights of the thyroid and seminal gland. Serum testosterone levels and the Leydig cells nuclei volume were decreased by BaP exposure whereas the StAR expression was increased. Histopathological changes in the testis also were detected in the males exposed to BaP. These results showed that prepubertal BaP-exposure adversely influenced the male reproductive system in the adult life, indicating that a comprehensive risk assessment of BaP-exposure on prepubertal period is necessary.

Venlafaxine-induced damage to seminiferous epithelium, spermiation, and sperm parameters in rats: A correlation with high estrogen levels

BACKGROUND

Venlafaxine (selective serotonin and norepinephrine reuptake inhibitor) use has increased worldwide. However, the impact of venlafaxine on testes and sperm parameters has not been investigated.

OBJECTIVES

We evaluated venlafaxine impact on testicular and sperm parameters and verified whether the changes are reversible.

METHODS

Animals from venlafaxine-35 days and venlafaxine-65 days groups received 30 mg/kg of venlafaxine for 35 days. Control-35 days and control-65 days received distilled water. In control-65 days and venlafaxine-65 days, the treatment was interrupted for 30 days. Sperm concentration, morphology, motility, and mitochondrial activity were analyzed. Number of step 19 spermatids (NLS), frequency of tubules with spermiation failure, Sertoli cells number, and TUNEL-positive germ cells were quantified. Testicular aromatase, connexin 43 (Cx43) immunoexpression, Cx43 protein levels, and Cx43 expression were evaluated. Either intratesticular testosterone or estrogen levels were measured.

RESULTS

Venlafaxine impaired sperm morphology, reduced sperm concentration, mitochondrial activity, and sperm motility. The frequency of tubules with spermiation failure and NLS increased in parallel to increased Cx43 immunoexpression; mRNA and protein levels; and aromatase, testosterone, and estrogen levels. An increase in germ cell death and decreased Sertoli cells number were observed. In venlafaxine-65 days, except for sperm motility, mitochondrial activity, Sertoli cells number, and germ cell death, all other parameters were partially or totally recovered.

CONCLUSION

Venlafaxine increases testosterone aromatization and Cx43. This drug, via high estrogen levels, disturbs Sertoli cells, induces germ cell death, and impairs spermiation and sperm parameters. The restoration of spermiation associated with the decreased Cx43 and hormonal levels in venlafaxine-65 days reinforces that high estrogen levels are related to venlafaxine-induced changes. The presence of damaged Sertoli cells, germ cell death, and low sperm motility in venlafaxine-65 days indicates that interruption of treatment for 30 days was insufficient for testicular recovery and points to a long-term estrogen impact on the seminiferous epithelium.

The effect of vitamin B12 supplement on post-thaw motility, viability and DNA damage of human sperm

Sperm cryopreservation may lead to adverse effects on sperm structure and function. Cyanocobalamin (vitamin B12) has antioxidant potential and can protect DNA from free radical-induced damages. Recent studies have shown that vitamin B12 preserves glutathione that leads to modulate oxidative stress responses. Also, vitamin B12 might act directly as a scavenger of ROS. The aim of this study was to investigate the effects of vitamin B12 supplementation on human sperm parameters during the cryopreservation process. Thirty semen samples were obtained from normozoospermic men. Using cryopreservation medium supplemented with different concentrations of vitamin B12 (0, 0.5, 1, 2, 2.5 mg/ml), the semen samples were cryopreserved. After thawing, all samples were evaluated for motility and viability. Based on results, 2 mg/ml was considered as the optimal concentration of vitamin B12 for evaluating sperm DNA fragmentation. The results showed that 1 and 2 mg/ml vitamin B12 significantly increased post-thawing motility and viability compared with the 0 mg/ml vitamin B12 (p < .05). Also, by supplementing with 2 mg/ml vitamin B12, DNA fragmentation decreased when compared to the control. The present study showed that cryopreservation medium supplemented with vitamin B12 at 2 mg/ml could improve sperm quality after freeze-thaw process.

Vitamin B12 Prevents Cimetidine-Induced Androgenic Failure and Damage to Sperm Quality in Rats

Cimetidine, used as an anti-ulcer and adjuvant treatment in cancer therapy, causes disorders in the male reproductive tract, including steroidogenesis. However, its effect on sperm quality and male fertility has been poorly addressed. Since vitamin B₁₂ has demonstrated to recover spermatogonia number and sperm concentration in cimetidine-treated rats, we evaluated the impact of cimetidine on sperm quality and fertility potential and whether vitamin B₁₂ is able to prevent the harmful effect of this drug on steroidogenesis and sperm parameters. Adult male rats were treated for 52 consecutive days as follows: cimetidine group (100 mg/kg of cimetidine), cimetidine/vitamin B₁₂ group (100 mg/kg of cimetidine + 3 μg vitamin B₁₂), vitamin B₁₂ group (3 μg vitamin B₁₂) and control group (saline). Serum testosterone levels and immunofluorescence associated to western blot for detection of 17β-HSD6 were performed. Sperm morphology and motility, mitochondrial activity, acrosome integrity, DNA integrity by Comet assay, lipid peroxidation as well as fertility potential were analyzed in all groups. Apoptotic spermatids were also evaluated by caspase-3 immunohistochemistry. In the cimetidine-treated animals, reduced serum testosterone levels, weak 17β-HSD6 levels and impaired spermiogenesis were observed. Low sperm motility and mitochondrial activity were associated with high percentage of sperm tail abnormalities, and the percentage of spermatozoa with damaged acrosome and DNA fragmentation increased. MDA levels were normal in all groups, indicating that the cimetidine-induced changes are associated to androgenic failure. In conclusion, despite the fertility potential of rats was unaffected by the treatment, the sperm quality was significantly impaired. Therefore, considering a possible sperm-mediated transgenerational inheritance, the long term offspring health needs to be investigated. The administration of vitamin B₁₂ to male rats prevents the androgenic failure and counteracts the damage inflicted by cimetidine upon sperm quality, indicating that this vitamin may be used as a therapeutic agent to maintain the androgenic status and the sperm quality in patients exposed to androgen disrupters.

Fluoxetine-induced androgenic failure impairs the seminiferous tubules integrity and increases ubiquitin carboxyl-terminal hydrolase L1 (UCHL1): Possible androgenic control of UCHL1 in germ cell death?

The selective serotonin reuptake inhibitor fluoxetine has been used for the treatment of depression. Although sexual disorders have been reported in male patients, few studies have demonstrated the fluoxetine effect on the reproductive histophysiology, and the target of this antidepressant in testes is unknown. We evaluated the impact of short-term treatment with fluoxetine on the adult rat testes, focusing on steroidogenesis by Leydig cells (LC) and androgen-dependent testicular parameters, including Sertoli cells (SC) and peritubular myoid cells (PMC). Since UCHL1 (ubiquitincarboxyl-terminal hydrolase L1) seems to control spermatogenesis, the immunoexpression of this hydrolase was also analyzed. Adult male rats received 20 mg/kg BW of fluoxetine (FG) or saline (CG) for eleven days. In historesin-embedded testis sections, the seminiferous tubule (ST) and epithelial (Ep) areas, and the LC nuclear diameter (LCnu) were measured. The number of abnormal ST, androgen-dependent ST, SC and PMC was quantified. Testicular β-tubulin levels and peritubular actin immunofluorescence were evaluated. Serum testosterone levels (STL) and steroidogenesis by 17β-HSD6 immunofluorescence were analyzed, and either UCHL1-immunolabeled or TUNEL-positive germ cells were quantified. In FG, abnormal ST frequency increased whereas ST and Ep areas, androgen-dependent ST number, LCnu, 17β-HSD6 activity and STL reduced significantly. TUNEL-positive PMC and SC was related to decreased number of these cells and reduction in peritubular actin and β-tubulin levels. In FG, uncommon UCHL1-immunoexpression was found in spermatocytes and spermatids, and the number of UCHL1-immunolabeled and TUNEL-positive germ cells increased in this group. These findings indicate that LC may be a fluoxetine target in testes, impairing PMC-SC integrity and disturbing spermatogenesis. The increase of UCHL1 in the damaged tubules associated with high incidence of cell death confirms that this hydrolase regulates germ cell death and may be controlled by androgens. The fertility in association with the androgenic status of patients treated with fluoxetine should be carefully evaluated.

Reduced levels of stromal sex hormone-binding globulin and androgen receptor dysfunction in the sperm storage region of the rat epididymis

The cauda epididymidis is the major sperm storage region whose androgenic supply, essential for the sperm viability, is provided by the vasculature and is dependent upon testosterone diffusion through the stromal tissue to reach the epithelial cells. We have focused our efforts on examining the regulation of this important epididymal region by evaluating the impact of the androgen disrupter cimetidine on the epithelial–stromal androgenic microenvironment. Male rats received 100 mg/kg cimetidine (CMTG) or saline (CG) for 50 days, serum testosterone levels were measured and the epididymal cauda region was processed for light and transmission electron microscopy. In the proximal cauda region, the duct diameter was measured and birefringent collagen in the stroma was quantified. TUNEL-labeled epithelial cells were quantified, and androgen receptor (AR), karyopherin alpha (KPNA) and sex hormone-binding globulin (SHBG) levels were analyzed by immunofluorescence and Western blot. CMTG showed reduced duct diameter and high number of apoptotic epithelial cells. In the epithelium, the total AR concentration and the KPNA immunoreactivity were reduced, and a weak/absent AR nuclear immunofluorescence was observed in contrast to the enhanced AR immunolabeling observed in the cytoplasm of the epithelial cells. A significant reduction of collagen and SHBG levels in the stroma was also observed. Cimetidine treatment impairs AR nuclear import in the epithelium, causing androgenic dysfunction and subsequent epithelial cell apoptosis and duct atrophy. The connective tissue atrophy and reduction of SHBG stromal levels associated with epithelial androgenic dysfunction indicate a possible role of stromal SHBG in the androgenic supply of the sperm storage region of the epididymis.

Vitamin B12-induced spermatogenesis recovery in cimetidine-treated rats: effect on the spermatogonia number and sperm concentration

The H₂-receptor antagonist cimetidine is an antiulcer drug also used for the treatment of cancer due to its antiangiogenic effect. However, this drug has caused structural changes in the seminiferous tubules. Vitamin B₁₂ has been used as a therapeutic agent for the treatment of male infertility. The supplementation of rats with vitamin B₁₂ during cimetidine treatment has recovered the damaged seminiferous tubules, but how this vitamin restores the seminiferous epithelium has not been clarified. In this study, we evaluated whether vitamin B₁₂ improves the number of spermatogonia, spermatocytes, and sperm concentration in cimetidine-treated rats. Adult male rats were treated for 50 days as follows: cimetidine group received 100 mg kg⁻¹ b.w. of cimetidine, cimetidine-B₁₂ group received cimetidine and 3 μg of vitamin B₁₂-hydroxocobalamin, B₁₂ group received only 3 μg of vitamin, and control group received saline. Sperm concentration was calculated and historesin-embedded testes sections were used for the quantitative analyses of spermatogonia (A; In/B) and spermatocytes. TUNEL method and PCNA immunofluorescence were performed. Cimetidine caused a significant reduction in sperm concentration. TUNEL-positive spermatogonia and spermatocytes were correlated to a significant reduction in the number of these cells. In cimetidine-B₁₂ group, sperm concentration was higher than cimetidine group and a significant increase in the number of spermatogonia (stages II–VI) was correlated to a high incidence of PCNA-immunolabeled spermatogonia and spermatocytes. The results show that the supplementation of rats with vitamin B₁₂ during cimetidine treatment increases sperm concentration and exerts a potential effect in the recovery of spermatogonia and spermatocytes.

Ameliorative effect of vitamin B12 on seminiferous epithelium of cimetidine-treated rats: a histopathological, immunohistochemical and ultrastructural study

Cimetidine is an H2 receptor antagonist that has an antiandrogenic effect. It intervenes with the conversion of testosterone into estrogen in the Sertoli cells with accompanying testicular structural changes. In the present study, the microscopic and the ultrastructural changes induced by cimetidine and the effect of vitamin B12 as a protective agent on rat testes were studied. Immunoexpression of estrogen receptor β (ERβ) in testes was evaluated. Twenty-four adult male rats were divided into four groups: control, cimetidine-treated, vitamin B12 treated, and combined cimetidine and vitamin B12 treated. The experimental rats were administered with cimetidine and/or vitamin B12 for 52 days. Group II rats showed marked atrophy of the seminiferous tubules with a significant increase in tubular diameter and decrease in the tubular luminal and epithelial areas. Ultrastructure of this group showed irregular Sertoli cells with basal cytoplasmic vacuolation and significantly thickened basement membrane. ERβ immunoexpression was similar to controls. Group III rats showed near normal seminiferous tubular structures with minimal cellular alterations and the immunoreactivity of the testicular sections was very close to normal. However, group IV rats showed markedly immunopositive detached cells, spermatids, and primary spermatocytes. Cimetidine interferes with the control of spermatogenesis as evidenced by microscopic and ultrastructural studies and affection of ERβ receptors and vitamin B12 has a protective action against this harmful effect.

The antineoplastic busulphan impairs peritubular and Leydig cells, and vitamin B12 stimulates spermatogonia proliferation and prevents busulphan-induced germ cell death

Busulphan (Bu), an alkylating agent used for bone marrow and spermatogonial stem cell transplantation (SSCT), impairs Sertoli (SC) cells, which are necessary for the spermatogonial stem cell (SSC) homing during transplantation. As Leydig (LC) and peritubular myoid (PMC) cells are essential for SC support and maintenance of spermatogonial niche, we evaluated the impact of Bu on the LC and PMC structural integrity. Vitamin B₁₂ (B₁₂) has demonstrated beneficial effects against drug-induced testicular changes; thus, we also examined whether this vitamin is able to stimulate spermatogonia mitotic activity and prevent Bu-induced germ cell death. Rats received 10mg/kg of Bu in the 1st and 4th days, and daily B₁₂ supplementation during Bu treatment and for 6days after the last injection of Bu (Bu-6d), totaling 10days of treatment. Other animals received the same treatment as Bu-6d, and B₁₂ supplementation (Bu+7dB₁₂) or saline (Bu+7dS) for 7 more days, totaling 17days of treatment. Serum testosterone levels were measured. In the historesin-embedded testis sections, the seminiferous tubule and epithelial areas were measured, and the number of spermatogonia and PMC was quantified. Actin and 17β-HSD6 immunofluorescence was detected, and the number of TUNEL-positive LC and germ cells was computed. In Bu-6d, PMC number reduced, and a weak actin immunoexpression and death in these cells was observed. The testosterone levels reduced, and the interstitial tissue showed a weak 17β-HSD6 immunoexpression and increased number of TUNEL-positive LC. In Bu+7dB₁₂, the number of spermatogonia was higher than in Bu-6d and Bu+7dS, and the number of TUNEL-positive germ cells was significantly lower than in Bu+7dS. Bu exerts a harmful impact on PMC and LC, reducing the testosterone levels. Vitamin B₁₂ prevents significantly Bu-induced germ cell death and stimulates spermatogonia proliferation, being a useful strategy for the enrichment of SSC in vitro and an adjuvant therapy for spermatogenesis recovery in oncologic patients.

Vitamin B12 and Semen Quality

Various studies have revealed the effects of vitamin B₁₂, also named cobalamin, on semen quality and sperm physiology; however, these studies collectively are still unsummarized. Here, we systematically discuss and summarize the currently understood role of vitamin B₁₂ on semen quality and sperm physiology. We searched the Web of Science, PubMed, and Scopus databases for only English language articles or abstracts from September 1961 to March 2017 (inclusive) using the key words “vitamin B₁₂” and “cobalamin” versus “sperm”. Certain relevant references were included to support the empirical as well as the mechanistic discussions. In conclusion, the mainstream published work demonstrates the positive effects of vitamin B₁₂ on semen quality: first, by increasing sperm count, and by enhancing sperm motility and reducing sperm DNA damage, though there are a few in vivo system studies that have deliberated some adverse effects. The beneficial effects of vitamin B₁₂ on semen quality may be due to increased functionality of reproductive organs, decreased homocysteine toxicity, reduced amounts of generated nitric oxide, decreased levels of oxidative damage to sperm, reduced amount of energy produced by spermatozoa, decreased inflammation-induced semen impairment, and control of nuclear factor-κB activation. However, additional research, mainly clinical, is still needed to confirm these positive effects.

Seminiferous epithelium damage after short period of busulphan treatment in adult rats and vitamin B12 efficacy in the recovery of spermatogonial germ cells

Several different strategies have been adopted in attempt to recover from chemotherapy-damaged spermatogenesis that is often seen in oncologic patients. In this study, we have evaluated the impact of short period of exposure to busulphan on the haemogram and seminiferous epithelium of adult rats, focusing on spermatogonial depletion and Sertoli cell (SC) integrity. We then examined whether vitamin B₁₂ supplementation improves the haematological parameters and spermatogonia number. The animals received 10 mg/kg of busulphan (BuG) or busulfan+vitamin B₁₂ (Bu/B₁₂ G) on the first and fourth days of treatment. In H.E.-stained testicular sections, the areas of the seminiferous tubule (ST) and seminiferous epithelium were measured. The number of spermatogonia in H.E-stained and PCNA-immunolabelled testicular sections was quantified. The frequency of tubules with abnormal SC nuclei or TUNEL-positive SC was evaluated. Vimentin immunofluorescence in ST was also evaluated. In BuG and Bu/B₁₂ G, the animals showed leukopenia and thrombocytopenia, but the body weight reduced only in BuG. The areas of ST and seminiferous epithelium decreased in Bu/B₁₂ G and BuG. In BuG, the number of H.E.-stained and PCNA-immunolabelled spermatogonia reduced significantly. The frequency of tubules containing abnormal SC nuclei and TUNEL-positive SC increased and the vimentin immunoexpression pattern changed. In Bu/B₁₂ G, the number of H.E.-stained or PCNA-immunolabelled spermatogonia increased fourfold in comparison with BuG. The structural changes in ST after 6 days of busulphan exposure may be associated with the potential effect of this anti-neoplastic agent on SC. The increased number of spermatogonia in the busulphan-treated animals receiving vitamin B₁₂ indicates that this vitamin can be an adjuvant therapy to improve the fertility in male cancer patients.

NF-kB overexpression and decreased immunoexpression of AR in the muscular layer is related to structural damages and apoptosis in cimetidine-treated rat vas deferens

BACKGROUND

Cimetidine, histamine H2 receptors antagonist, has caused adverse effects on the male hormones and reproductive tract due to its antiandrogenic effect. In the testes, peritubular myoid cells and muscle vascular cells death has been associated to seminiferous tubules and testicular microvascularization damages, respectively. Either androgen or histamine H2 receptors have been detected in the mucosa and smooth muscular layer of vas deferens. Thus, the effect of cimetidine on this androgen and histamine-dependent muscular duct was morphologically evaluated.

METHODS

The animals from cimetidine group (CMTG; n=5) received intraperitoneal injections of 100 mg/kg b.w. of cimetidine for 50 days; the control group (CG) received saline solution. The distal portions of vas deferens were fixed in formaldehyde and embedded in paraffin. Masson´s trichrome-stained sections were subjected to morphological and the following morphometrical analyzes: epithelial perimeter and area of the smooth muscular layer. TUNEL (Terminal deoxynucleotidyl-transferase mediated dUTP Nick End Labeling) method, NF-kB (nuclear factor kappa B) and AR (androgen receptors) immunohistochemical detection were also carried out. The birefringent collagen of the muscular layer was quantified in picrosirius red-stained sections under polarized light. The muscular layer was also evaluated under Transmission Electron Microscopy (TEM).

RESULTS

In CMTG, the mucosa of vas deferens was intensely folded; the epithelial cells showed numerous pyknotic nuclei and the epithelial perimeter and the area of the muscular layer decreased significantly. Numerous TUNEL-labeled nuclei were found either in the epithelial cells, mainly basal cells, or in the smooth muscle cells which also showed typical features of apoptosis under TEM. While an enhanced NF-kB immunoexpression was found in the cytoplasm of muscle cells, a weak AR immunolabeling was detected in these cells. In CMTG, no significant difference was observed in the birefringent collagen content of the muscular layer in comparison to CG.

CONCLUSIONS

Cimetidine induces significant damages in the epithelium; a possible antiandrogenic effect on the basal cells turnover should be considered. The cimetidine-induced muscle cells apoptosis confirms the susceptibility of these cells to this drug. The parallelism between enhanced cytoplasmic NF-kB immunolabeling in the damaged muscular tissue and muscle cell apoptosis suggests that this drug may avoid the translocation of NF-kB to the nucleus and interfere in the control of NF-kB-mediated smooth muscle cell apoptosis. The decreased immunoexpression of ARs verified in the damaged muscular tissue reinforces this possibility.

Late morfofunctional alterations of the Sertoli cell caused by doxorubicin administered to prepubertal rats

BACKGROUND

Doxorubicin is a potent chemotherapeutic drug used against a variety of cancers. It acts through interaction with polymerases and topoisomerase II and free radical production. Doxorubicin activity is not specific to cancer cells and can also damage healthy cells, especially those undergoing rapid proliferation, such as spermatogonia. In previous studies our group showed that etoposide, another topoisomarese II poison, causes irreversible damage to Sertoli cells. Thus, the aim of this study was to address the effects of doxorubicin on Sertoli cell morphology and function and on the seminiferous epithelium cycle when administered to prepubertal rats.

METHODS

Prepubertal rats received the dose of 5 mg/Kg of doxorubicin, which was fractioned in two doses: 3 mg/Kg at 15dpp and 2 mg/Kg at 22 dpp. The testes were collected at 40, 64 and 127 dpp, fixed in Bouin's liquid and submitted to transferrin immunolabeling for Sertoli cell function analysis. Sertoli cell morphology and the frequency of the stages of the seminiferous epithelium cycle were analyzed in PAS + H-stained sections.

RESULTS

The rats treated with doxorubicin showed reduction of transferrin labeling in the seminiferous epithelium at 40 and 64 dpp, suggesting that Sertoli cell function is altered in these rats. All doxorubicin-treated rats showed sloughing and morphological alterations of Sertoli cells. The frequency of the stages of the seminiferous epithelium cycle was also affected in all doxorubicin-treated rats.

CONCLUSIONS AND DISCUSSION

These data show that doxorubicin administration during prepuberty causes functional and morphological late damage to Sertoli cells; such damage is secondary to the germ cell primary injury and contributed to enhance the spermatogenic harm caused by this drug. However, additional studies are required to clarify if there is also a direct effect of doxorubicin on Sertoli cells producing a primary damage on these cells.