Changes In Seminiferous Epithelium Research Articles

Nanoparticle toxicity may cause testicular dysfunction

Nanoparticle toxicity may cause testicular dysfunction

Age-related and photoperiodic variation of the DAZ gene family in the testis of the Syrian hamster (Mesocricetus auratus).

SummaryThe Deleted in AZoospermia (DAZ) gene family regulates the development, maturation and maintenance of germ cells and spermatogenesis in mammals. The DAZ family consists of two autosomal genes, Boule and Dazl (Daz-like), and the Daz gene on chromosome Y. The aim of this study was to analyze the localization of DAZL and BOULE during testicular ontogeny of the seasonal-breeding Syrian hamster, Mesocricetus auratus. We also evaluated the testicular expression of DAZ family genes under short- or long-photoperiod conditions. In the pre-pubertal and adult testis, DAZL protein was found mainly in spermatogonia. BOULE was found in the spermatogonia from 20 days of age and during the pre-pubertal and adult period it was also detected in spermatocytes and round spermatids. DAZL and BOULE expression in spermatogonia was strictly nuclear only in 20-day-old hamsters. We also detected the novel mRNA and protein expression of BOULE in Leydig cells. In adult hamsters, Dazl expression was increased in regressed testis compared with non-regressed testis and DAZL protein expression was restricted to primary spermatocytes in regressed testis. These results show that DAZL and BOULE are expressed in spermatogonia at early stages in the Syrian hamster, then both proteins translocate to the cytoplasm when meiosis starts. In the adult regressed testis, the absence of DAZL in spermatogonia might be related to the decrease in germ cell number, suggesting that DAZ gene family expression is involved in changes in seminiferous epithelium during photoregression.

Structural and Ultrastructural Study of Rat Testes Influenced by Electromagnetic Radiation

This study was conducted to investigate the influence of whole-body electromagnetic radiation (EMR) on testicular parenchyma of Wistar rats. Sexually mature rats were subjected to pulsed electromagnetic field at frequency of 2.45 GHz and mean power density 2.8 mW/cm2 by 3-h daily applications for 3 wk. Tissue samples were obtained 3 h after the last irradiation and processed by histological techniques for light and transmission electron microscopy. Testes showed apparent degenerative changes of seminiferous epithelium. The seminiferous tubules were mostly irregular in shape, and seminiferous epithelium contained a number of empty spaces of different size. Subsequently, groups of sloughed epithelial cells were often found inside the lumina of tubules. Except for relatively unchanged Sertoli cells, some locations of basal compartment of seminiferous epithelium contained shriveled Sertoli cells with dark cytoplasm. These areas showed degenerative features including necrotizing and shriveled spermatogonia surrounded by empty irregular spaces, and undulating basement membrane. The intertubular spaces were enlarged but interstitial Leydig cells did not show any marked morphological changes. Evidence demonstrates the adverse effects of EMR on testicular parenchyma in rats.

Apoptosis contributes to testicular toxicity induced by two isomers of bromopropanes

The aim of this study was to investigate the different testicular toxicity and the role of apoptosis in the possible mechanism induced by the two isomers of bromopropanes (BPs) in the same dosage. Following the 14-day treatment with a single dose of 1-BP and 2-BP (1 g/kg), male rats were killed and a series of experiments were performed. 1-BP and 2-BP both significantly decreased the epididymal sperm count, while only 2-BP induced an increase in sperms with abnormal heads. Morphological evaluation showed that 1-BP did not cause morphological changes in seminiferous epithelium, but 2-BP treatment resulted in the disappearance of spermatogonia, atrophy of the seminiferous tubules and degeneration of germ cells. 2-BP significantly increased the TUNEL-positive cells and the activation of caspase-3 and decreased the genes and proteins expression of Bax, Bcl-2 and p53. In contrast, there were no significant changes in the expression of apoptosis-related genes and proteins in 1-BP group, though the TUNEL-positive cells were significantly increased. Taken together, this study indicated that those two isomers both have toxicity in male rats, however, the testicular toxicity and the role of apoptosis in the toxic mechanism induced by 1-BP and 2-BP may be different.

Testicular toxicity in cannabis extract treated mice: association with oxidative stress and role of antioxidant enzyme systems

Intraperitoneal injection of cannabis extract at low doses (total doses ranging from 40 mg to 60 mg per mouse) induced adverse effect on testes and oxidative stress. At low doses, there was a significant increase in lipid peroxidation and decrease in testicular lipid content, but the effects were significantly less at higher doses and at the withdrawal of cannabis treatment (recovery dose). There was a marked decrease in antioxidant enzyme profiles (superoxide dismutase, catalase and glutathione peroxidase) and glutathione content at low doses, but these effects were higher at higher dose and at withdrawal of the treatment (recovery effect). Histology revealed significant shrinkage of tubular diameter and detrimental changes in seminiferous epithelium of testis with resulting lowered serum testosterone and pituitary gonadotropins (follicular stimulating [FSH] and luteinizing hormones [LH]) levels at low doses. But at higher doses and particularly at withdrawal of the treatment, regression of various germ cell layers of testes through the revival of testosterone hormone and pituitary gonadotropins (FSH and LH) were observed, indicating that recovery effects on testes became operative possibly through the corrective measure of endogenous testicular antioxidant enzymes profiles and pituitary gonadotropins hormones feedback mechanisms.

Effect of δ-9-tetrahydrocannabinol on altered antioxidative enzyme defense mechanisms and lipid peroxidation in mice testes

The present study examined the adverse effects of δ-9-tetrahydrocannabinol (i.p injection in albino mice) on free radical damage of testicular lipids (lipid peroxidation) at low doses and the role of antioxidant enzymes defense system at high dose and particularly at the withdrawal of the drug after applying higher dose (recovery dose). At lower doses (total doses ranging from 6 mg to 28 mg), there was a significant increase of lipid peroxidation and decrease in testicular lipid content. But the effects were slightly lowered at high dose (total dose 70 mg) and at the withdrawal of the drug (recovery dose). Similarly, marked decrease of antioxidant enzyme systems (superoxide dismutase, catalase, and glutathione peroxidase) and glutathione content were noticed at low doses. But the effects were slightly higher at high dose and at the withdrawal of the drug. Similarly, low-dose treatments caused significant shrinkage of tubular diameter and detrimental changes in seminiferous epithelium of testis resulting in lowered plasma testosterone and pituitary gonadotropins (follicular stimulating and luteinizing hormone levels. But at high dose and particularly at withdrawal of the drug, regression of seminiferous tubules and recovery of various germ cell layers of testes through the revival of testosterone hormone and pituitary gonadotropins were observed.

From testicular biopsy to human embryo

The aim of the study was to investigate the role of a testicular biopsy in the diagnosis and therapy of infertile men with a non-obstructive azoospermia. Overall, 70 testicular biopsies from infertile men were analysed. Samples were obtained by the "open testicular biopsy" method. After dissection, several pieces of the tissue were immediately immersed into the Sperm Prep Medium (Medi-Cult) and fixative (5.5% buffered glutaraldehyde). Tissue samples transported in Sperm Prep Medium were plunged into Sperm Freezing Medium (Medi-Cult) and were stored in liquid nitrogen for potential in vitro fertilization procedures. The tissue was also processed for semithin sections and transmission electron microscopy. Semithin sections from 8 infertile patients demonstrated regular testis structure and fully preserved spermatogenesis (control biopsies). In the remaining 62 cases, spermatogenesis was impaired and a variety of pathological changes could be seen: disorganization and desquamation of spermatogenic cells, spermatid or spermatocyte "stop", spermatogonia only, "Sertoli cells only" or tubular fibrosis. However, in 65% of cases (despite the above mentioned changes of seminiferous epithelium) foci of preserved spermatogenesis could be detected. These cases were classified as "mixed atrophy" of seminiferous tubules. In 63% of infertile patients, a successful extraction of sperm from the biopsy could be performed. In azoospermic patients, histological analysis of testicular biopsy proved to be very useful in terms of diagnosis as well as therapy, i.e. for further in vitro fertilization procedures.

Hypothalamic-Pituitary-Gonadal Axis in the Mutant Weaver Mouse

The weaver (wv) mutant mouse manifests severe locomotor defects, a deficiency in granule cells of the cerebellum, and cellular deficits in the midbrain dopaminergic system. The wv phenotype is associated with a missense mutation in the pore region of the G-protein-gated inwardly rectifying potassium channel, GIRK2. The homozygous male wv mouse is essentially infertile due to an inadequate level of sperm production. Females are fertile although they also manifest the neurological phenotype. Homozygotes of both sexes have reduced body weight. We have evaluated the hypothalamic-pituitary-gonadal axis in heterozygote and homozygote male and female wv mutants in comparison with wild-type controls. Testicular weight was significantly reduced in the homozygous males, due to degenerative changes of seminiferous epithelium. Serum and pituitary content of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin were normal in all groups, and the normal sex differences were noted (FSH and LH higher in males, prolactin higher in females). Pituitary growth hormone (GH) concentration was normal, with control and mutant males showing higher GH than females. Serum testosterone levels were normal in the mutants, as was testicular testosterone. Testicular α-inhibin content was mildly reduced, but high in proportion to testicular weight. The defect in spermatogenesis appeared predominantly in the postmeiotic stages. In situ hybridization was consistent with expression of some GIRK2 mRNA isoforms in seminiferous epithelium. There were no significant differences between genotypes in the levels of dopamine, dihydroxyphenylacetic acid, serotonin and 5-hydroxyindoleacetic acid in the mediobasal and preoptic hypothalamic regions. Homovanillic acid levels in these two areas were, however, reduced in wv homozygotes compared to wild-type animals. In the light of normal pituitary hormone levels, normal hypothalamic monoamine concentrations and normal sex differences in gonadotropins, we conclude that the infertility in the male homozygote wv mouse lies within the tubule and is probably a primary defect in the germ cells. The hormonal data suggest that Leydig cell function, and at least some aspects of Sertoli cell function, are normal in the mutant mice.

CDDP投与時のラットセルトリ細胞 Tight Junction のランタン透過性の変化

Using electron microscope, distribution of lanthanum tracer in the seminiferous epithelium was evaluated in adult male rats 2, 7, 25 and 53 days after single intraperitoneal injection of 3 mg/kg of CDDP. Lanthanum penetrated beyond the tight junction between Sertoli cells and the maximum penetration around the spermatid was found on the 7th day, when any degenerative changes of seminiferous epithelium were not recognized light microscopically. And 4 weeks pretreatment with Cephalantin and Kallikulein had no effects on this lanthanum tracer penetration around the spermatid. On decreasing this lanthanum tracer penetration after 7 days, some lanthanum was also found around the spermatocytes on the 53rd day but not around the spermatid. It is proposed that lanthanum tracer penetration beyond the Sertoli cell tight junction may be a morphological marker of early Sertoli cell dysfunction after CDDP administration.

Changes of seminiferous epithelium in hybrids of mice carrying Robertsonian karyotype.

Different wild mouse populations have been found in Italy characterized by different Robertsonian karyotypes. Hybrids between carriers of karyotype have severe impairment of fertility due to different Robertsonian rearrangements, because of the difficulties of the meiotic chromosome pairing. Homozygous Robertsonian mice (Cittaducale, CD, Ancarano, ACR and Lipari Island, LIP) are able to release mature spermatozoa while in hybrid F1 mice (CD X ACR, ACR X LIP, and LIP X CD) the impairment of seminiferous epithelium cycle is evidenced by a germinal aplasia. In the hybrid mice the more predominant lesion is represented by a pathological arrangement of the basement membrane introflecting and splitting inside the seminiferous epithelium.