Proteomic biomarkers in seminal plasma as predictors of reproductive potential in azoospermic men.

Introduction: Azoospermia, characterized by an absence of sperm in the ejaculate, represents the most severe form of male infertility. While surgical sperm retrieval in obstructive azoospermia (OA) is successful in the majority of cases, patients with non-obstructive azoospermia (NOA) show retrieval rates of only about 50% and thus frequently have unnecessary surgery. Surgical intervention could be avoided if patients without preserved spermatogenesis are identified preoperatively. This prospective study aimed to discover biomarkers in seminal plasma that could be employed for a non-invasive differential diagnosis of OA/NOA in order to rationalize surgery recommendations and improve success rates. Methods: All patients signed written informed consent, underwent comprehensive andrological evaluation, received human genetics to exclude relevant pathologies, and patients with azoospermia underwent surgical sperm retrieval. Using label-free LC-MS/MS, we compared the proteomes of seminal plasma samples from fertile men (healthy controls (HC), n=8) and infertile men diagnosed with 1) OA (n=7), 2) NOA with successful sperm retrieval (mixed testicular atrophy (MTA), n=8), and 3) NOA without sperm retrieval (Sertoli cell-only phenotype (SCO), n=7). Relative abundance changes of two candidate markers of sperm retrieval, HSPA2 and LDHC, were confirmed by Western Blot. Results: We found the protein expression levels of 42 proteins to be significantly down-regulated (p ≤ 0.05) in seminal plasma from SCO NOA patients relative to HC whereas only one protein was down-regulated in seminal plasma from MTA patients. Analysis of tissue and cell expression suggested that the testis-specific proteins LDHC, PGK2, DPEP3, and germ-cell enriched heat-shock proteins HSPA2 and HSPA4L are promising biomarkers of spermatogenic function. Western blotting revealed a significantly lower abundance of LDHC and HSPA2 in the seminal plasma of men with NOA (SCO and MTA) compared to controls. Discussion: The results indicate that certain testis-specific proteins when measured in seminal plasma, could serve as indicators of the presence of sperm in the testis and predict the success of sperm retrieval. Used in conjunction with conventional clinical assessments, these proteomic biomarkers may assist in the non-invasive diagnosis of idiopathic male infertility.

Therapeutic effects of thymoquinone or capsaicin on acrylamide-induced reproductive toxicity in rats mediated by their effect on oxidative stress, inflammation, and tight junction integrity.

In the field of environmental toxicology, endocrine-disrupting effects have become a major concern. The present research set out to investigate the possible reproductive toxicity of acrylamide. The research was also expanded to explore the protective effects of two nutraceuticals, thymoquinone (TQ) and capsaicin, against acrylamide-induced reproductive toxicity. Six groups of sixty male albino rats were created. Group 1 was used as a control. Rats were administered a daily dose of acrylamide and acted as the model in Group 2. TQ was provided to rats once a day in Group 3. Capsaicin was administered to rats once a day in Group 4. TQ was given once daily to rats exposed to acrylamide in Group 5. Rats were given capsaicin once a day for eight weeks after being exposed to acrylamide in Group 6. Acrylamide induced oxidative stress, testicular NF-κB/p65 expression, and down-regulated the expression of occludin, all of which can contribute to its testicular toxicity, while TQ or capsaicin removes all of these toxicity signs. TQ and capsaicin have shown efficacy in alleviating all of the acrylamide's toxic insults in the current reproductive toxicity model. Both nutraceuticals upregulated the expression of occludin in testicular tissue and restored tight junction integrity, in addition to their well-known antioxidant and anti-inflammatory effects, which were confirmed in this study.

Medical management of non-obstructive azoospermia: A systematic review.

While most men with non-obstructive azoospermia (NOA) are not amenable to medical treatment, some men can be treated effectively with hormonal therapy, prior to considering surgery. In some cases, hormonal therapy alone can treat NOA, without the need for surgery. In other cases, correction of a potential hormonal imbalance can enhance the chances of success of surgical sperm retrieval (SSR), with either conventional or microdissection testicular sperm extraction. Abnormal testicular function and low androgen levels can result from a primary dysfunction, a medical or surgical condition, or from an exogenous factor, and should be managed prior to more invasive interventions. Even men with normal androgen levels may benefit from hormonal therapy before sperm retrieval. Moreover, SSR may cause testicular injury and aggravate the pre-existing situation. If surgical extraction of sperm fails, it leaves the patients with less satisfactory options, like donor sperm or adoption. Therefore, it is the role of the infertility specialist to be vigilant and identify reversible causes of NOA, such as hormonal imbalance, prior to considering surgery. In the present paper we will systematically review the literature and highlight the available conventional medical regimens, as well as experimental ones. Abbreviations: ART: assisted reproductive technology; CAH: congenital adrenal hyperplasia; EAU: European Association of Urology; hCG: human chorionic gonadotrophin; HH: hypogonadotrophic hypogonadism; hMG: human menopausal gonadotrophin; IUI: intrauterine insemination; micro-TESE: microdissection testicular sperm extraction; NOA: non-obstructive azoospermia; OR: odds ratio; SCO: Sertoli-cell only; SERM: selective oestrogen receptor modulator; SRR: sperm retrieval rate; SSC: spermatogonia stem cell; TART: testicular adrenal rest tumour; WMD: weighted mean difference.

Effectiveness of mesenchymal stem cells cultured under hypoxia to increase the fertility rate in rats (Rattus norvegicus).

BACKGROUND AND AIM: Mesenchymal stem cells (MSCs) transplanted into the testes of rats with testicular failure can help rescue fertility. However, the low viability of transplanted MSCs limits the success of this treatment. This study aimed to determine the effectiveness of MSCs cultured under hypoxia to increase the fertility rate in rats (Rattus norvegicus). MATERIALS AND METHODS: Bone marrow-derived MSCs (200 million cells/rat) were transplanted into male rat models with induced infertility (10 rats/treatment group) after 4 days of culture in 21% O2 (normoxia) and 1% O2 (hypoxia). Ten fertile and 10 untreated infertile rats served as controls. In the infertile male rats that had been fasted from food for 5 days, the fasting condition induced malnutrition and then resulted in testicular failure. RESULTS: The results indicated that the MSCs cultured under hypoxic conditions were more effective than those cultured in normoxic conditions as a treatment for testicular failure in infertile male rats based on the increased number of cells expressing p63 as a quiescent cell marker and ETV5 as a transcription factor expressed in Sertoli and germ cells. Furthermore, the structure of the seminiferous tubules, which contain spermatogonia, primary and secondary spermatocytes, and spermatid, Sertoli, and Leydig cells, was improved in infertile male rats treated with the MSCs cultured under hypoxic conditions. CONCLUSION: The testicular transplantation of MSCs cultured under hypoxic conditions was an effective treatment for testicular failure in rats.

Alpha-lipoic acid effectively attenuates ionizing radiation-mediated testicular dysfunction in rats: Crosstalk of NF-ĸB, TGF-ß, and PPAR-ϒ pathways.

Radiotherapy is one of the principal approaches employed in the treatment of pelvic cancers. Nevertheless, testicular dysfunction and infertility are among the most common adverse effects in young adult cancer survivors. Clinically, alpha-lipoic acid (LA) has been applied to improve the quality of sperm with a satisfactory effect. Therefore, the present study investigated the underlying mechanisms of the radioprotective effects of LA against testicular damage. Male Sprague-Dawley rats were exposed to 10 Gy of whole-body ϒ-radiation and LA (50 mg/kg, P.O.) was administered one week before and three days post-irradiation. LA showed remarkable capacity in preserving testicular tissue against radiation damage by improving histological and ultrastructural changes of disorganized seminiferous tubules, besides enhancing its diameter, germinal epithelial thickness, and Johnsen's score. Radiation instigated a significant decrease in sperm quality and quantity associated with depletion of serum testosterone levels, while the LA administration maintained spermatogenesis. Strikingly, LA exhibited antioxidant properties by restoring reduced glutathione levels and antioxidant enzyme activities such as catalase and glutathione-s-transferase, besides diminishing malondialdehyde levels in the testis of irradiated group. Furthermore, LA alleviated testicular inflammation through downregulation of nuclear factor-ĸB (NF-ĸB) expression with a subsequent reduction in interleukin (IL)-6 and cyclooxygenase-2 expression, accompanied by the augmented expression of the anti-inflammatory cytokine IL-10. Additionally, testicular fibrosis markers including Masson's trichrome and transforming growth factor (TGF)-ß expression were noticeably declined in LA-treated irradiated rats, together with the upregulation of peroxisome proliferator-activated receptor-ϒ expression. Collectively, LA ameliorates radiation-mediated spermatogenesis-defects and testicular-damage via suppression of oxidative stress/NF-ĸB/TGF-ß signaling.

Androgen Treatment in Adolescent Males With Hypogonadism.

During adolescence, androgens are responsible for the development of secondary sexual characteristics, pubertal growth, and the anabolic effects on bone and muscle mass. Testosterone is the most abundant testicular androgen, but some effects are mediated by its conversion to the more potent androgen dihydrotestosterone (DHT) or to estradiol. Androgen deficiency, requiring replacement therapy, may occur due to a primary testicular failure or secondary to a hypothalamic-pituitary disorder. A very frequent condition characterized by a late activation of the gonadal axis that may also need androgen treatment is constitutional delay of puberty. Of the several testosterone or DHT formulations commercially available, very few are employed, and none is marketed for its use in adolescents. The most frequently used androgen therapy is based on the intramuscular administration of testosterone enanthate or cypionate every 3 to 4 weeks, with initially low doses. These are progressively increased during several months or years, in order to mimic the physiology of puberty, until adult doses are attained. Scarce experience exists with oral or transdermal formulations. Preparations containing DHT, which are not widely available, are preferred in specific conditions. Oxandrolone, a non-aromatizable drug with higher anabolic than androgenic effects, has been used in adolescents with preserved testosterone production, like Klinefelter syndrome, with positive effects on cardiometabolic health and visual, motor, and psychosocial functions. The usual protocols applied for androgen therapy in boys and adolescents are discussed.

Comparison of biotechnological culture of hypoxia-conditioned rat mesenchymal stem cells with conventional in vitroculture of normoxia-conditioned rat mesenchymal stem cells for testicular failure therapy with low libido in rats.

AIM: Biotechnological culture of hypoxia-conditioned (CH) rat mesenchymal stem cells (rMSC-CH) for testicular failure therapy with low libido improves the functional outcome of the testicle for producing spermatogenic cells and repairs Leydig cells in rats (Rattus norvegicus). MATERIALS AND METHODS: In the first group (T1), rats with testicular failure and low libido were injected with normoxia-conditioned (CN) rMSCs (21% oxygen); in the second group (T2), rats with testicular failure and low libido were injected with rMSC-CH (1% oxygen); in the negative control group (T-), rats with normal testis were injected with 0.1 mL phosphate-buffered saline (PBS); and in the sham group (TS), rats with testicular failure and low libido were injected with 0.1 mL of PBS. RESULTS: Vascular endothelial growth factor expression, as the homing signal, in the groups T2, T-, T1, and TS was 2.00±0.5%, 2.95±0.4%, 0.33±0.48%, and 0±0%, respectively. The number of cluster of differentiation (CD)34+ and CD45+ cells in the groups T- and TS was <20%, whereas that in T1 and T2 groups was >30% and >80%, respectively, showing the mobilization of hematopoietic stem cells (HSCs). The number of spermatogenic cells (spermatogonia, primary spermatocytes, secondary spermatocytes, and spermatid) decreased significantly (p<0.05) in TS compared with that in T-, T1, and T2, whereas that in T2 did not show a significant (p>0.05) decrease compared to that in T-. The improvement in libido, based on the number of Leydig cells producing the hormone testosterone for libido expression, did not increase in T1, whereas T2 was able to maintain the number of Leydig cells significantly compared to that between TS and T1. CONCLUSION: rMSC-CH culture for testicular failure with low libido showed improvement in the functional outcome of the testicle and in repairing Leydig cells.

Testicular sperm extraction in men with sertoli cell-only testicular histology - 1680 cases.

OBJECTIVE: To study the outcomes of testicular sperm extraction (TESE) among men with pure Sertoli cell-only histology identified during diagnostic testicular biopsy. METHODS: This retrospective cohort study involved 1680 cases of patients with nonobstructive azoospermia (NOA) diagnosed with pure Sertoli cell-only histology who underwent testicular biopsy with TESE in a reference center in Brazil by a single surgeon. Sperm retrieval rates (SSR) were the main outcome measure. RESULTS: Overall, 14.83% of patients with Sertoli cell-only had sperm retrieved with TESE in quantity that allowed the performance of ICSI. No differences were observed in SSR based on testis volume (<15 mL vs. <15 mL) or serum FSH level. CONCLUSIONS: Patients with Sertoli cell-only histology can be counseled that they have some likelihood of sperm retrieval with TESE. Based on the findings, patients to be submitted to testicular biopsy for histologic analysis may be concomitantly prepared for ICSI with TESE in case sperm is available.

Advances in sperm retrieval techniques in azoospermic men: A systematic review.

OBJECTIVE: To evaluate various methods of operative sperm retrieval in men with non-obstructive azoospermia (NOA) and to determine the optimal surgical approach in terms of effectiveness, morbidity, and complications. MATERIALS AND METHODS: PubMed and Cochrane databases were searched to identify five recent reviews and meta-analyses evaluating outcomes for sperm retrieval in men with NOA. RESULTS AND CONCLUSION: Micro-TESE is the most efficient method for retrieving sperm but requires special expertise and can be traumatic for the testes. Conventional biopsies are twice more likely to retrieve sperm than fine-needle aspiration. Testicular aspiration performed by multiple passes into the testis is traumatic and is not efficient for sperm retrieval. Needle-aspiration biopsy and open real-time testicular mapping by the single seminiferous tubule technique can offer less traumatic methods for sperm retrieval, which can be tried before proceeding to micro-TESE. The first attempt at sperm retrieval is the best chance the patient has and should combine various techniques sequentially to give the highest chance of success with the least morbidity.

Recent advances in the genetics of testicular failure / 亚洲男科学杂志(英文版)

Infertility affects approximately 15% of couples, and male factor is responsible for 30%-50% of all infertility. The most severe form of male infertility is testicular failure, and the typical phenotype of testicular failure is severely impaired spermatogenesis resulting in azoospermia or severe oligozoospermia. Although the etiology of testicular failure remains poorly understood, genetic factor typically is an underlying cause. Modern assisted reproductive techniques have revolutionized the treatment of male factor infertility, allowing biological fatherhood to be achieved by many men who would otherwise have been unable to become father to their children through natural conception. Therefore, identifying genetic abnormalities in male is critical because of the potential risk of transmission of genetic abnormalities to the offspring. Recently, along with other intense researches ongoing, whole-genome approaches have been used increasingly in the genetic studies of male infertility. In this review, we focus on the genetics of testicular failure and provide an update on the advances in the study of genetics of male infertility.

Sexual dichotomy of gonadal function in Prader-Willi syndrome from early infancy through the fourth decade.

STUDY QUESTION: At what age does the type of hypogonadism, namely hypothalamic or primary gonadal defect, become established in men and women with Prader-Willi syndrome (PWS)? SUMMARY ANSWER: The type of hypogonadism becomes established only in late adolescence and early adulthood. WHAT IS KNOWN ALREADY: The etiology of hypogonadism in PWS is heterogeneous and the clinical expression is variable. Primary testicular failure is common in PWS men, while combinations of ovarian dysfunction and gonadotrophin deficiency are seen in women. STUDY DESIGN, SIZE, DURATION: This is a prospective study of a cohort of 106 PWS patients followed for a mean duration of 4.5 years. Serial blood samples were obtained and assayed for gonadotrophins, inhibin B, anti-Mullerian hormone (AMH), dehydroepiandrosterone sulfate (DHEAS), testosterone (males), and estradiol (females). Results were compared with normal reference values obtained from the literature. For the purpose of this study, we defined the following age groups: infants <1 year; children 1-10 years; adolescents 11-20 years and adults >20 years. PARTICIPANTS/MATERIALS, SETTING, METHODS: Study participants were 49 males (aged 2 months to 36 years) and 57 females (aged 1 month to 37 years) with genetically confirmed diagnoses of PWS (deletions 60, uniparental disomy 54, imprinting center defect 2) followed in the Israel national multidisciplinary PWS clinic. MAIN RESULTS AND THE ROLE OF CHANCE: Serum LH levels were in the normal range (1.0-6.0 mIU/ml) for 7/10 adult men, and high in 3, while FSH (normal range 1.0-6.1 mIU/ml) was elevated (34.4 ± 11.5 mIU/ml) in 6 and normal (3.5 ± 1.6 mIU/ml) in 4 men. Testosterone was low (5.7 ± 3.4 nmol/l) compared with the normal range of 12.0-34.5 nmol/l in the reference population in all men >20 years. AMH showed a normal decrease with age, despite low testosterone levels. Inhibin B was normal (241 ± 105 pg/ml) in infant boys, but low or undetectable in most adult men. Hormonal profiles were more heterogeneous in women than in men. Estradiol was consistently detectable in only 7/13 adult women. Inhibin B was low or undetectable in all PWS females although occasional samples showed levels within the normal range of 15-95 pg/ml. Vaginal bleeding was reported to occur for the first time in eight women at a median age of 20 years (13-34 years), but only one had regular monthly menses. The type of hypogonadism (primary or secondary) in PWS can be determined only after age 20 years. LIMITATIONS, REASONS FOR CAUTION: The study cohort was heterogeneous, showing variability in BMI, cognitive disability and medical treatment. WIDER IMPLICATIONS OF THE FINDINGS: Demonstration of the natural history of reproductive hormone development in PWS suggests that androgen replacement may be indicated for most PWS boys in mid-adolescence. Recommendations for hormone replacement in PWS women need to be individually tailored, serial measurements of inhibin B should be performed, and contraception should be considered in those women who may have the potential for fertility.

Microdissection testicular sperm extraction in men with Sertoli cell-only testicular histology.

OBJECTIVE: To study the outcomes of microdissection testicular sperm extraction (microTESE) among men with pure Sertoli cell-only histology on diagnostic testicular biopsy. DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. PATIENT(S): Six hundred forty patients with pure Sertoli cell-only histology on testicular biopsy who underwent microTESE by a single surgeon. INTERVENTION(S): MicroTESE. MAIN OUTCOME MEASURE(S): Sperm retrieval rates. RESULT(S): Overall, 44.5% of patients with Sertoli cell only had sperm retrieved with microTESE. No difference was noted in sperm retrieval rates based on testis volume (≥15 mL vs. <15 mL, 35.3% vs. 46.1%, respectively). Patients with ≥15 mL testicular volume and FSH 10-15 mU/mL had the worst prognosis, with a sperm retrieval rate of 6.7%. CONCLUSION(S): Patients with previous testicular biopsy demonstrating Sertoli cell-only histology can be counseled that they have a reasonable likelihood of sperm retrieval with the contemporary delivery of microTESE. Given this finding, the utility of testicular biopsy before microTESE is further questioned.

Regulation of male fertility by the bone-derived hormone osteocalcin.

Traditionally, bone has been viewed as a relatively static tissue only fulfilling mechanical and scaffolding function. In the past decade however, this classical view of the bone has considerably evolved towards a more complex picture. It is now clear that the skeleton is not only a recipient for hormonal input but it is also an endocrine organ itself. Through the secretion of an osteoblast-derived molecule, osteocalcin, the skeleton regulates glucose homeostasis and male reproductive functions. When undercarboxylated, osteocalcin acts following its binding to a G-coupled receptor, Gprc6a, on pancreatic ß cells to increase insulin secretion, on muscle and white adipose tissue to promote glucose homeostasis and on Leydig cells of the testis to favor testosterone biosynthesis. More recently, it was also shown that osteocalcin acts via a pancreas-bone-testis axis that regulates, independently of and in parallel to the hypothalamus-pituitary-testis axis, male reproductive functions by promoting testosterone biosynthesis. Lastly, in trying to expand the biological relevance of osteocalcin from mouse to human, it was shown that Gprc6a is a potential new susceptibility locus for primary testicular failure in humans. Altogether, these results shed new light on the importance of the endocrine role of the skeleton and also provide credence to the search for additional endocrine functions of this organ.

Técnicas del futuro: ingeniería de tejidos y uso de células madre en medicina reproductiva / Future's technology: tissue engineering and stem cells in reproductive medicine

Últimamente ha cobrado gran interés en la comunidad médica y científica, el avance experimentado por la medicina regenerativa, la ingeniería de tejidos y el uso de terapias celulares en base a células autólogas maduras, como también el uso de células madre. Desde que se levantó en Estados Unidos, la prohibición de investigar con células madre embrionarias, se ha producido un aumento de las investigaciones en este campo. El interés por estas investigaciones, se ha traspasadoa la comunidad no científica, que se encuentra expectante frente al progreso que se logre, con las terapias derivadas de tales estudios. En medicina reproductiva, existe la esperanza de poder producir células germinales tanto femeninas como masculinas (ovocitos o sus precursores y espermatozoides o sus precursores), a partir de células madre, para tratar pacientes con falla gonadal (ovárica o testicular), que hasta ahora resuelven su problema de infertilidad, mediante el uso de gametos donados, prevaleciendo la falla endocrina, que se resuelve con la administración de reemplazo hormonal. Las células madre son células indiferenciadas, toti potenciales que bajo ciertas condiciones, pueden diferenciarse a células especializadas. La medicina regenerativa se vale de la ingeniería de tejidos y las terapias celulares con células autólogasmaduras y también con células madre. Este artículo es una revisión bibliográfica sobre las últimas investigaciones en el campo de la medicina regenerativa y el uso de células madre en medicina reproductiva. Se describen los diferentes tipos de células madre y los tejidos que se ha logrado reproducir in vitro hasta ahora, como también algunos estudios en animales y su aplicación en humanos.

In the last years, the scientific and non-scientific community have been motivated by the great advances in the field of regenerative medicine, tissue engineering and cell therapies (using either mature autologous cells or stem cells). Since the beginning of 2009, once the prohibition of research in embryonic stem cells was abolished, there has been an increase in research in this field. There is great expectation, specially in the field of reproductive medicine and infertility where there exists the hope to produce germinal cells (oocytes and sperms) to treat couples with gonadal failure (ovarian o testicular). In these patients, gamete donation and permanent hormonal replacement therapy have resolved their fertility and/or endocrine problems. Regenerative medicine uses tissue engineering, and cell therapies to repair the function of a damaged organ. Stem cells are undifferentiated, toti potentially cells, that under certain conditions or milieu may differentiate to specialized cells. This article is a bibliographic review of the most recent investigations in the field of regenerative medicine and stem cell therapies, using animal models and their application to humans.

Adverse effects of a clinically relevant dose of hydroxyurea used for the treatment of sickle cell disease on male fertility endpoints.

Two experiments were conducted to determine: 1) whether the adult male transgenic sickle cell mouse (Tg58 x Tg98; TSCM), exhibits the patterns of reproductive endpoints (hypogonadism) characteristic of men with sickle cell disease (SCD) and 2) whether hydroxyurea (HU) exacerbates this condition. In Experiment 1, blood samples were collected from adult age-matched TSCM and ICR mice (ICRM) (N = 10/group) for plasma testosterone measurements. Subsequently, mice were sacrificed, testes excised and weighed and stored spermatozoa recovered for the determination of sperm density, progressive motility and percentage of spermatozoa with normal morphology. In experiment 2, adult male TSCM were orally treated with 25 mg HU/kg body weight/day for 28 or 56 days. Control mice received the vehicle for HU (saline) as described above. At the end of the treatment periods, blood samples were collected for quantification of circulating testosterone. Subsequently, mice were sacrificed, testes and epididymides were recovered and weighed and one testis per mouse was subjected to histopathology. Stored spermatozoa were recovered for the determination of indices of sperm quality mentioned in Experiment 1. Testis weight, stored sperm density, progressive motility, percentage of spermatozoa with normal morphology and plasma testosterone concentrations of TSCM were significantly lower by 40, 65, 40, 69 and 66%, respectively than those of ICRM. These data indicate that adult TSCM used in this study suffered from hypogonadism, characteristically observed among adult male SCD patients. In Experiment 2, HU treatment significantly decreased testis weight on day 28, (0.09 +/- 0.004 g) that was further decreased on day 56 (0.06 +/- 0.003 g; treatment x time interaction) compared with controls (day 28, 0.15 +/- 0.01 g; day 56, 2, 0.16 +/- 0.01 g). Concomitant with a 52% shrinkage (P<0.001) in area of testes in 56 days of HU treatment, testes from HU-treated TSCM exhibited significant atrophic degeneration in the seminiferous tubules compared with controls. Furthermore, treated TSCM had only Sertoli cells and cell debris remaining in most of the seminiferous tubules in comparison with controls. Leydig cell prominence and hyperplasia were more evident (P<0.05) in the steroidogenic compartments of testes of HU-treated TSCM compared with controls. However, plasma testosterone concentrations were reduced by HU treatment (P<0.05; treatment x time interaction) compared with controls on the two time periods studied. Epididymides from HU-treated TSCM sustained a 25% shrinkage (P<0.05), along with 69 (P<0.005) and 95% reduction (P<0.005), in stored sperm density and sperm progressive motility (treatment x time interaction P<0.05), respectively on day 56 of treatment compared with controls. These data demonstrate that TSCM used in this study exhibited SCD-induced hypogonadism, thus authenticating their use for studying the effect of HU on male reproductive endpoints observed in SCD patients. Secondarily, our data show that HU treatment exacerbated the already SCD-induced hypogonadism to gonadal failure.