Efficiency Of Spermatogenesis Research Articles

Testicular Histomorphometric Evaluation of Zebu Bull Breeds

The objective of this study was to evaluate the quantitative histology and testicular biometrics in zebu bulls of different breeds. Testicular fragments of Nelore (n=10), Polled Nelore (n=6), Gir (n=5), Guzerat (n=5) and Tabapuã bulls (n=5) were used. The fragments were perfusion-fixed in Karnovsky solution, embedded in glycol methacrylate and stained with toluidine blue-1% sodium borate. The Nelore animals had a higher tubular volumetric proportion (85.2%) and greater height of the seminiferous epithelium (73.2 µm) than the Gir, Guzerat and Tabapuã breeds. The Nelore animals also had a higher volumetric proportion of Leydig cells (5.2%) than the Guzerat and Tabapuã breeds. There was no significant difference for any of these parameters between the Nelore and Polled Nelore breeds. The gonadosomatic index, seminiferous tubule diameter, cross-sectional area of the seminiferous tubule and tubule length (total length and length per gram of testicular parenchyma) did not vary among the breeds studied. The morphometric parameters evaluated suggested that the genetic selection applied to the Nelore and Polled Nelore breeds improved the efficiency of spermatogenesis in these breeders.

The tubular compartment and the spermatogenic dynamics of the wild rodent Oxymycterus nasutus (Rodentia: Cricetidae)

Despite the order Rodentia present worldwide distribution and large number of species in the Brazilian fauna, detailed studies on testicular morphophysiology are still scarce. Therefore, this study aimed to analyze the dynamics of the spermatogenic process of Oxymycterus nasutus using morphometrical and stereological tools. Testicles from ten sexually mature males were used, showing a gonadosomatic index of 0.89%. The testicular parenchyma showed one of the highest tubulesomatic indexes reported among wild rodents – 0.82% – from which 65.12% was allocated into seminiferous epithelium. The average tubular diameter was 249.89μm, whereas the epithelium height was 62.47μm and the total length was 18.62m per gram of testis. Eight different stages of the seminiferous epithelium cycle were described. Stage 1 was used for counting the germ cell population as well as the Sertoli cells. On average, 3.47 type-A spermatogonia, 24.39 primary spermatocytes in preleptotene/leptotene, 24.13 primary spermatocytes in pachytene, 68.38 round spermatids and 7.33 Sertoli cells were found per tubular cross section. There were 91.02×106 Sertoli cells per gram of testis and each cell was able to support 9.33 spermatids and 16.43 germ cells. The coefficient of spermatogonial mitosis was 7.02, while 2.83 spermatids were produced for each primary spermatocyte in pachytene. The overall efficiency of spermatogenesis was 19.70 cells, whereas the sperm reserve per gram of testis totalized 849.63×106 spermatids. Therefore, the presented data showed that O. nasutus shows a high energetic investment in reproduction, corroborating the findings for other species of the Cricetidae family.

Pharmacological stimulation of the regenerative capacity of rat testes damaged by paclitaxel.

Productivity of spermatogenesis and the population of spermatogonial cells were substantially reduced in male Wistar rats 3 months after administration of cytostatic drug paclitaxel, damaging stem spermatogonia. However, signs of reparative regeneration appeared in the testicular tissue. In animals receiving paclitaxel in combination with granulocyte CSF, the same period of observation, the number of spermatogonia and the efficiency of spermatogenesis at the same terms of the study did not differ from those in intact animals. Intensive recovery processes started 1 month earlier than after administration of paclitaxel alone. These data attest to pronounced potentiating effect of granulocyte CSF on reparative regeneration of the testicular tissue.

MP66-18 EVIDENCE OF SPERMATOGENIC DIFFERENTIATION OF HUMAN EMBRYONIC STEM CELLS IN AN IN VITRO HOLLOW FIBER MODEL

You have accessJournal of UrologyInfertility: Basic Research, Physiology & Pathophysiology1 Apr 2014MP66-18 EVIDENCE OF SPERMATOGENIC DIFFERENTIATION OF HUMAN EMBRYONIC STEM CELLS IN AN IN VITRO HOLLOW FIBER MODEL Meenakshi Gaur, Connie John, Cyril Ramathal, Renee Reijo Pera, and Paul Turek Meenakshi GaurMeenakshi Gaur More articles by this author , Connie JohnConnie John More articles by this author , Cyril RamathalCyril Ramathal More articles by this author , Renee Reijo PeraRenee Reijo Pera More articles by this author , and Paul TurekPaul Turek More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.2065AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Replicating human spermatogenesis in vitro has applications in reproductive toxicology of drugs and chemicals and, in the long-term, could involve the treatment of male infertility. Although mouse embryonic stems cells have been successfully differentiated to functional sperm in vitro, the full sequence of human spermatogenesis has not been similarly reproduced. By employing a sterile, hollow fiber model, we sought to differentiate human embryonic stem cells along the spermatogenic sequence and report our success to date. METHODS A 0.5 mm pore size membrane hollow fiber (HF) bioreactor unit was connected to a Cellmax Artificial Capillary Oxygenator Module (Spectrum Laboratories, Inc.). Human Sertoli cells (20 x 106) derived from cadaveric tissue and H1 human embryonic stem cells (hESs) transfected to express mcherry, DAZ, DAZL, and Boule (7 x 106) were introduced to the HF. Inner and outer chambers were filled with complete medium and the assembly incubated at 37°C in 5% CO2. Medium samples were collected from the inside and outside HF chambers and tested for glucose levels. Cells within the bioreactor were then forcibly eluted and evaluated histologically after parafilm embedding and also assessed for viability, immunofluorescence, and gene expression. RESULTS The sterile HF bioreactor containing viable Sertoli cells was maintained for 42 days. At that time, viable hESs were also observed in the bioreactor (see Figure, left panel, green stain). Gene expression studies showed active DAZL (see Figure, right panel, red stain) and VASA expression in cultured HF cells indicating the active differentiation along the germ cell pathway within the HF bioreactor. CONCLUSIONS It is possible to promote the viability and partial germ line differentiation of hESs in vitro in a sterile hollow fiber model that mimics the architecture of the natural seminiferous tubule. Further research is needed to create culture conditions that allow for mature sperm production and increased efficiency of spermatogenesis. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e747 Advertisement Copyright & Permissions© 2014MetricsAuthor Information Meenakshi Gaur More articles by this author Connie John More articles by this author Cyril Ramathal More articles by this author Renee Reijo Pera More articles by this author Paul Turek More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Melatonin improves spermatogonial stem cells transplantation efficiency in azoospermic mice.

Transplantation quality improvement and reduction of cellular damage are important goals that are now considered by researchers. Melatonin is secreted from the pineal gland and some organs such as testes. According to beneficial effects of melatonin (such as its antioxidant and antiapoptotic properties), researchers have proposed that the use of melatonin may improve transplantation quality. The aim of this study was to investigate the effects of melatonin on the spermatogonial stem cells transplantation in the azoospermic mice. The testes of the BALB/c mice pups (6-day-old) after vitrified-thawed, were digested with enzymes (collagenase, DNaseΙ, trypsin-EDTA) to disperse the cells. The SSCs, type A, were isolated from the rest of testicular cells by MACS. Spermatogonial stem cells were labeled with PKH26 fluorescent kit. Labeled spermatogonial stem cells were transplanted into the testes of infertile mice (busulfan 40 mg/kg). The mice died two months after transplantation and the efficiency of spermatogenesis was investigated. TNP2 and hematoxyline-eosin staining were used to detect the efficiency of cell transplantation. TNP2 were detected in the samples that received melatonin and spermatogonial stem cells transplantation, simultaneously. TNP2 was not detectable in the transplant recipient mice that received placebo for 10 weeks (control group). According to hematoxyline-eosin staining, melatonin improved structure of testes. Administration of melatonin (20 mg/kg) simultaneously with transplantation of spermatogonial stem cells in azoospermia mouse testis increases the efficiency of transplantation and improves structural properties of the testes tissue.

Testis evaluation of adult Wistar rats after neonatal treatment with fluoxetine

In current assay the serotoninergic system in newly-born Wistar rats underwent pharmacological modification by fluoxetine, a selective serotonin reuptake inhibitor (SSRI), to investigate its repercussion on testicular parameters in adult animals. Thirty animals were distributed according to treatment: control animals (n = 6), animals treated with 1 mg kg -1 (n = 6), 5 mg kg -1 (n = 6), 10 mg kg -1 (n = 6) and 20 mg kg -1 (n = 6) of fluoxetine (IP). When 150 days old, the animals were anesthetized and perfused intra-cardiacally with fixative solution. Testes were routinely processed for inclusion in plastic resin (methacrylate glycol). Further, 4 µm-thick histological sections were stained with toluidine blue/sodium borate 1% and analyzed histometrically. Pharmacological intervention on the serotoninergic system during the postnatal period of the testes development in Wistar rats with fluoxetine chlorohydrate reduced parameters, such as testicular weight, testis liquid weight and seminiferous tubules diameter. However, testicular parameters, such as daily sperm production (DSP), spermatogenesis efficiency (DSP/g/testis) and cell population in stage VII of adult animals, were not influenced by fluoxetine chlorohydrate usage during neonatal period. Results show that administration of fluoxetine during 21 days after birth may induce adverse changes in the spermatogenesis of adult rats.

<b>Testis morphophysiology of rats treated with nandrolone decanoate and submitted to physical training</b> - doi: 10.4025/actascihealthsci.v35i2.16406

The mammalian testis is a complex organ with endocrine and exocrine functions. It consists of seminiferous tubules where the production of the male gametes called spermatogenesis occurs. This process is influenced by a number of factors including the use of physical performance-enhancing drugs. The objective of this study was to evaluate the effects of the anabolic steroid nandrolone decanoate on the morphofunctional structure of testes in sedentary rats and rats subjected to moderate aerobic exercise training. Twenty-four male rats were divided into four experimental groups: sedentary control, sedentary treated, trained control and trained treated.The training lasted eight weeks and consisted of running on a programmable ergometer treadmill, tailored to train eight rats simultaneously. Treated animals received intramuscular injections of nandrolone decanoate (0.5 mg kg -1 body weight) during the last four weeks of physical training, while the control groups received intramuscular injections of vehicle (vegetable oil).The male reproductive system morphology showed that treatment with nandrolone decanoate, in both sedentary and trained rats, promoted morphological and functional changes that result in reduced efficiency of spermatogenesis.

Effect of different cryoprotectant agents on spermatogenesis efficiency in cryopreserved and grafted neonatal mouse testicular tissue

Restoration of male fertility associated with use of the cryopreserved testicular tissue would be a significant advance in human and animal assisted reproductive technology. The purpose of this study was to test the effects of four different cryoprotectant agents (CPA) on spermatogenesis and steroidogenesis in cryopreserved and allotransplanted neonatal mouse testicular tissue. Hank’s balanced salt solution (HBSS) with 5% fetal bovine serum including either 0.7M dimethyl sulfoxide (DMSO), 0.7M propylene glycol (PrOH), 0.7M ethylene glycol (EG), or glycerol was used as the cryoprotectant solution. Donor testes were collected and dissected from neonatal pups of CD-1 mice (one day old). Freezing and seeding of the testicular whole tissues was performed using an automated controlled-rate freezer. Four fresh (non-frozen) or frozen–thawed pieces of testes were subcutaneously grafted onto the hind flank of each castrated male NCr nude recipient mouse and harvested after 3months. Fresh neonatal testes grafts recovered from transplant sites had the most advanced rate of spermatogenesis with elongated spermatid and spermatozoa in 46.6% of seminiferous tubules and had higher levels of serum testosterone compared to all other frozen–thawed-graft groups (p<0.05). Fresh grafts and frozen–thawed grafts in the DMSO group had the highest rate of tissue survival compared to PrOH, EG, and glycerol after harvesting (p>0.05). The most effective CPA for the freezing and thawing of neonatal mouse testes was DMSO in comparison with EG (p<0.05) in both pre-grafted and post-grafted tissues based on histopathological evaluation. Likewise, the highest level of serum testosterone was obtained from the DMSO CPA group compared to all other cryoprotectants evaluated (p<0.05). The typical damage observed in the frozen–thawed grafts included disruption of the interstitial stroma, intercellular connection ruptures, and detachment of spermatogonia from the basement membrane. These findings indicate that neonatal mouse testes were most effectively preserved when frozen with HBSS medium with DMSO and that the type of CPA is a significant factor to obtain the most advanced stages of spermatogenesis and steroidogenesis after cryopreservation, thawing, and transplantation of neonatal mouse testes.

A significant effect of the TSPY1 copy number on spermatogenesis efficiency and the phenotypic expression of the gr/gr deletion

AZFc deletions cause a significant phenotypic heterogeneity with respect to spermatogenesis; however, the reason for this is poorly understood. Recently, testis-specific protein Y-encoded 1 (TSPY1) copy number variation (CNV) was determined to be a potential genetic modifier of spermatogenesis. We performed a large-scale cohort study to investigate the effect of TSPY1 CNV on spermatogenesis and to elucidate the possible contribution of TSPY1 genetic variation to the phenotypic expression of AZFc deletions. Haplogrouping of the Y-chromosome and quantification of the TSPY1 copy number were performed in 2272 Han Chinese males with different spermatogenic statuses (704 males with the b2/b4 or gr/gr deletion and 1568 non-AZFc-deleted males). Our data revealed that the TSPY1 copy number distributions were significantly different among non-AZFc-deleted males with different spermatogenic phenotypes. Lower sperm production and an elevated risk of spermatogenic failure were observed in males with fewer than 21 TSPY1 copies and in those with more than 55 copies relative to men with 21-35 copies. Similar results were observed in males with the gr/gr deletion. These findings indicate that TSPY1 CNV affects an individual's susceptibility to spermatogenic failure by modulating the efficiency of spermatogenesis and strongly suggest that there is a significant quantity effect of the TSPY1 copy number on the phenotypic expression of the gr/gr deletion. To our knowledge, this CNV is the first independent genetic factor that has been clearly observed to influence the spermatogenic status of gr/gr deletion carriers. A combined genetic analysis of the TSPY1 copy number and the gr/gr deletion could inform the clinical counselling of infertile couples.

Association Study of Single‐Nucleotide Polymorphisms in FASLG, JMJDIA, LOC203413, TEX15, BRDT, OR2W3, INSR, and TAS2R38 Genes With Male Infertility

Infertility is a major health problem today, affecting about 15% of couples trying to conceive a child. Impaired fertility of the male factor is causative in 20% of infertile couples and contributory in up to another 30%-40%. Based on association studies, an increasing number of gene polymorphisms have been proposed to modulate the efficiency of spermatogenesis. Here, we have investigated the possible association of 9 single-nucleotide polymorphisms (SNP) in 8 different genes-FASLG, JMJDIA, LOC203413, TEX15, BRDT, OR2W3, INSR, and TAS2R38--with male infertility. We analyzed a total of 136 men with idiopathic infertility (60 azoospermic and 76 oligozoospermic) and 161 fertile controls. Our study group included individuals of different ethnic origin: 93 of the infertile men were Macedonians, 32 were Albanians, and 11 were of other origin. The control group was composed of 125 Macedonian and 36 Albanian men. The methodology included multiplex polymerase chain reaction/SNaPshot analyses, followed by capillary electrophoresis on an ABI3130 Genetic Analyzer. Of the 9 SNPs evaluated, 3 are significantly associated (P < .05) with male infertility: SNPs rs5911500 in LOC203413, rs3088232 in BRDT, and rs11204546 in OR2W3. SNP rs5911500 showed the strongest association with infertility among Albanians (P = .0001), whereas rs3088232 was most significantly associated with azoospermia among Macedonians (P = .0082). Moreover, the frequency of co-occurrence of LOC203413 minor T allele with either homozygosity or heterozygosity for the BRDT minor G allele was significantly higher among both azoospermic (6 of 60 [10%]; P = .0057; odds ratio [95% confidence interval], 8.83 [1.73-45.08]) and oligozoospermic (10 of 76 [13.2%]; P = .0002; odds ratio [95% confidence interval], 12.04 [2.57-56.47]) men in comparison with fertile controls (2 of 161 [1.2%]).

Influence of microsurgical varicocelectomy on human sperm mitochondrial DNA copy number: a pilot study

There is good evidence to show that varicocele repair can improve conventional sperm parameters, as well as, sperm DNA integrity, in infertile men with a clinical varicocele. To examine the effect of varicocelectomy on sperm quality, specifically, sperm nuclear chromatin integrity and sperm mitochondrial DNA (mtDNA) copy number. A prospective study done between March 2007 and January 2008. We evaluated a consecutive series of infertile men (n = 14) presenting to Ovo clinic with one year or more history of infertility, a clinically palpable varicocele and poor motility (<25 % rapid progressive and <50 % progressive). Microsurgical sub-inguinal varicocelectomy. Conventional sperm parameters, sperm mtDNA copy number (by real time PCR) and sperm chromatin structure assay (SCSA) parameters (%DFI,% HDS) before and 4 months after microsurgical varicocelectomy. Sperm concentration and SCSA parameters (%DFI and %HDS) improved significantly after surgery (P < 0.05). Sperm mitochondrial DNA copy number decreased significantly after surgery (27 ± 30 to 9 ± 6 copies per sperm, respectively, P = 0.032). There was a significant negative correlation between mitochondrial DNA copy number and sperm motility (r = - 0.71, P = 0.002). These findings support the concept that correction of a varicocele can improve spermatogenesis and sperm function, as mitochondrial DNA copy number has been suggested to reflect the efficiency of spermatogenesis and has been inversely related to sperm motility.

Spermatogenesis in goats with and without scrotum bipartition

The objective of the present research was to quantify the seminiferous epithelium cells, spermatogenesis efficiency and characterize the ultrastrucure of Sertoli cells in goats. Eighteen goats were used and divided into three groups: Group I – goats without bipartition of the scrotum; Group II – animals with bipartition of the scrotum in up to 50% of the testicular length; Group III – goats with bipartition of the scrotum in more than 50% of the testicular length. The goat testes in Group III had a greater number of primary spermatocytes (25.37±4.55 cells per cross sections), spermatids (112±15.12 cells per cross sections), and Sertoli cells (9.46±1.74 cells per cross sections) than the animals in Groups I and II (P<0.05). The spermatogenic mitotic, meiotic, and general efficiency were greater in animals in Group III (1.25±0.28; 5.12±1.63; 6.44±1.96) when compared to those in Groups I and II. Sheet-like processes originated from the Sertoli cell body as simple and smooth structures which involved almost all the surface of germ cells. Slender cord-like processes originated from Sertoli cells and also from the sheet-like processes. The relative frequency of the cycle stages showed differences among the groups of goats studied, and the highest frequency was in Stage 3 (20.68% for goats in Group I, 21.15% for those in Group II, and 16.89% for the animals in Group III). In conclusion, goats with bipartition of the scrotum have a greater number of germ and Sertoli cells per cross section of seminiferous tubule, that indicated a greater sperm production when compared to the other groups, and the ultrastructure of the Sertoli cell process did not present any relationship with bipartition of the scrotum.

Purinergic signalling mobilizes mitochondrial Ca2+ in mouse Sertoli cells

Intimate bidirectional communication between Sertoli cells and developing germ cells ensures the integrity and efficiency of spermatogenesis. Yet, a conceptual mechanistic understanding of the physiological principles that underlie Sertoli cell autocrine and paracrine signalling is lacking. Here, we characterize a purinergic Ca(2+) signalling network in immature mouse Sertoli cells that consists of both P2X2 and P2Y2 purinoceptor subtypes, the endoplasmic reticulum and, notably, mitochondria. By combining a transgenic mouse model with a dedicated bioluminescence imaging device, we describe a novel method to monitor mitochondrial Ca(2+) mobilization in Sertoli cells at subcellular spatial and millisecond temporal resolution. Our data identify mitochondria as essential components of the Sertoli cell signalling 'toolkit' that control the shape of purinergic Ca(2+) responses, and probably several other paracrine Ca(2+)-dependent signals.

Testicular apoptosis after dietary zinc deficiency: Ultrastructural and TUNEL studies

The present study was conducted in Wistar rats to determine whether prepubertal dietary zinc deficiency causes apoptotic changes in testes. Prepubertal male Wistar rats (40–50 gm) were divided into 3 groups: zinc control (ZC), pairfed (PF), and zinc deficient (ZD). Control and pairfed groups were given a 100 ppm zinc diet while the deficient groups received 1 ppm zinc diet for 2 and 4 weeks (w), respectively. Ultrastructural studies revealed several apoptotic features such as wavy basement membrane, displaced nuclei, chromatin condensation, plasma membrane blebbing, nuclear membrane dissolution, loss of inter-Sertoli cell junctional complexes, and intercellular bridges and deformed mitochondria. A variable spectrum of sperm defects had also been visualized e.g., acrosomal deformities such as decapitation and a ring of condensed chromatin around the nuclear periphery, deformed sperm heads with a condensed nucleus, tail-elements with superfluous cytoplasm, and damage to the mitochondrial sheath and aggregation of spermatozoa within the membrane. This was further supported by TUNEL studies. Apoptotic index, epididymal sperm concentration, motility, and fertility index also revealed a significant (P < 0.05) decrease in zinc deficient groups (2 and 4 w) when compared with their respective control and pairfed groups. All the above findings are indicative that changes observed in the testes after dietary zinc deficiency are due to the onset of apoptosis. Increased apoptotic degeneration in testes may cause irreversible changes in the germ cells associated with decreased epididymal sperm concentration, motility, and fertility index which contributes to the low efficiency of spermatogenesis thereby indicating a possible role of zinc in fertility.

Xenografting of testis tissue from bison calf donors into recipient mice as a strategy for salvaging genetic material

The objective was to evaluate the long-term outcome of testis tissue xenografting from neonatal bison calves as a model for closely related rare or endangered ungulates. Testis tissue was collected postmortem from two newborn bison calves (Bison bison bison) and small fragments of the tissue were grafted under the back skin of immunodeficient recipient mice (n = 15 mice; eight fragments/mouse). Single xenograft samples were removed from representative recipient mice every 2 mo after grafting (for up to 16 mo). The retrieved xenografts were evaluated for seminiferous tubular density, tubular diameter, seminiferous tubular morphology, and identification of the most advanced germ cell type. Overall, 69% of the grafted testis fragments were recovered as xenografts. Xenografts weight increased (P < 0.02) approximately four-fold by 2 mo and 10-fold by 16 mo post-grafting. In testis xenografts, gradual maturational changes were evident, manifested as the first detection of the following at the times specified: seminiferous tubule expansion, 2 mo; spermatocytes, 6 mo; round spermatids, 12 mo; and elongated spermatids, 16 mo. Furthermore, there were differences between the two donor calves regarding the efficiency of spermatogenesis in xenografts. The timing of complete spermatogenesis approximately corresponded to the reported timing of sexual maturation in bison. This study demonstrated, apparently for the first time, that testis tissue xenografting from neonatal bison donors into recipient mice resulted in testicular maturation and complete development of spermatogenesis in the grafts.

Effect of the nandrolone decanoate on the efficiency of spermatogenesis of sedentary rats and rats subjected to physical training

Spermatogenesis is a complex, highly organized and coordinated process that results in the production of male gametes. This process is influenced by a number of drugs that enhance physical performance, which have been used mainly by young people, athletes or not, seeking to gain athletic performance or only a prominent social position. The objective of this study was to evaluate the effects of the anabolic steroid nandrolone decanoate on the efficiency of spermatogenesis in sedentary rats and rats subjected to physical training. Twenty-four male rats were divided into four experimental groups: sedentary control, sedentary treated, trained control and trained treated. Treated animals received intramuscular injection of nandrolone decanoate (0.5 mg kg-1 body weight) during the last four weeks of physical training. The training program consisted of running on a programmable ergometer treadmill, tailored to train eight rats simultaneously, for nine weeks. We evaluated the morphological and morphoquantitative profiles of the male reproductive system. The results showed that the treatment causes a reduction in the efficiency of spermatogenesis; however, when associated with physical training, this compensates for the anabolic action, keeping the process of spermatogenesis within normality.

Quantification of Rat Spermatogenesis in Late Puberty after Neonatal Hormonal Manipulation

ABSTRACTIt has been known for many years that estrogens administration to experimental animals during the neonatal period or adulthood can impair sperm production and maturation. In earlier studies the negative effects of E were explained only as a result of suppression of gonadotropin secretion during the treatment. We aimed to assess GC development on day 35 (different GC types) in tandem with Sertoli cell support toward GCs (efficiency of spermatogenesis) by complex systems of quantitative criteria. We used experimental model for manipulation of neonatal hormonal environment by treatment with DES-10 μg, DES-1 μg, DES-0.1 μg or GnRHa. DES-10 greatly affected testis development and spermatogenesis in rat whereas GnRHa was quite less effective in producing negative impact. In contrast during the onset of puberty (d 18) both treatments exerted similar negative effect, and this time dependent response of the testis corresponds to different hormonal profiles. Quantitative evaluation of late pubertal spermatogenesis demonstrate that the most differentiated GC population- spermatides was the most sensitive to hormonal manipulation compared to spermatogonia (Sg) and spermatocytes (Sc). Different mechanisms are probably involved in mediation of the effect of E and gonadotropins and direct E action on GC differentiation is suggested. Our finding would elucidate our understanding about the hormonal regulation of different germ sell steps of spermatogenesis.

The effect of donor age on progression of spermatogenesis in canine testicular tissue after xenografting into immunodeficient mice

The objective of this study was to examine the effect of donor age on progression of spermatogenesis in dog (Canis lupus familiaris) testis tissue after xenografting. In Experiment 1, canine testes were obtained by surgical castration. Based on developmental pattern of spermatogenesis at the time of grafting, donors were categorized as immature, young, and adult (<4, 4 to 6, and >6 mo old, respectively). Fragments of testis tissue were implanted subcutaneously on the back of immunodeficient mice; xenografts were retrieved and analyzed 4, 6, or 8 mo later. At 4 mo postgrafting, immature and young groups had higher graft recovery rates, graft weights, vesicular gland indices, seminiferous tubule numbers, and larger seminiferous tubular diameters compared with those of adult donor xenografts. At 8 mo postgrafting, immature donor xenografts had maintained growth and development as exhibited by greater graft weights, vesicular gland indices, seminiferous tubule numbers, and tubular diameters compared with those of adult donor xenografts. At this time point, growth and development of xenografts did not differ between immature and young donors, whereas those from young donors had greater seminiferous tubule numbers and diameters compared with those of adult donor xenografts. Elongated spermatids were the most advanced germ cell type present at 4 and 8 mo postgrafting in xenografts of immature age groups. In Experiment 2, the longer-term efficiency of spermatogenesis and the potential sperm production in xenografts from immature donor dogs were determined. Testis tissue from 2-mo-old donor dogs were grafted into recipient mice, and xenografts were retrieved after 13 mo. Complete spermatogenesis was present in 5 of 29 recovered xenografts, with isolation of fully formed sperm (up to 36.3 × 10 6 per gram tissue). In conclusion, immature and young donors (<6 mo of age) were the most promising donors for dog testis tissue xenografting. This strategy may offer an alternative for male germ-line preservation for canids that die prematurely or must be castrated before maturation.

Microscopic morphology and testis morphometry of captivity-bred Adult bullfrogs (Lithobates catesbeianus Shaw, 1802)

The aim of this work was to study the testicular morphometry of captivity-bred adult bullfrogs. Fifteen young adult male were studied, in the rainy season and a lengthy photoperiod. The GSI was established at 0.15%. The nuclear diameter of germinative and Leydig cells, the nucleolus diameter of Sertoli cells and the area of cysts and tubules were determined and the mean number of ISPC, IISPC and SPT per cyst and the mean number of cysts per tubule was estimated. The nucleoplasmatic proportion of the nucleus of the Leydig cell was 76.22%, indicating less cytoplasmic activity. Eight generations of spermatogonia were found. The spermatogenesis efficiency in meiosis and in mitosis was 63 and 49%, respectively. The spermatogenesis of bullfrog fited in the pattern of other captivity Anurans, with differences as the morphology of Sertoli and Leydig cells nuclei.

Epidemiology; diagnosis, and treatment of male hypogonadotropic hypogonadism

Hypogonadotropic hypogonadism (HH), or secondary hypogonadism, is a clinical condition due to an impairment of the pituitary function, characterized by low testosterone plasma levels associated with normal or low FSH and LH plasma levels. An impairment of gonadotropin secretion and, therefore, a reduced efficiency of spermatogenesis was reported to be frequently associated to conditions different from the classical causes of secondary hypogonadism. These conditions (metabolic, endocrine and eating disorders, physical exercise etc.) have been associated with a non-classical form of HH that could be called "functional" HH (FHH). FHH differs from the classical one by the evidence that gonadotropin levels are in the low-normal range, but are inadequate for the testosterone levels, that often are also in the low-normal range. This commentary aims at reviewing knowledge on the forms of male HH in order to indicate and discuss clinical context, diagnostic and therapeutic approach in the less known non-classical form, i.e. FHH.