Research progress on the relationship between extracellular vesicles and male infertility / 中国综合临床

Infertility is gradually becoming a major problem affecting health worldwide, and male factors also play an important role in infertility. Extracellular vesicles (EVs) are ultramicro membranous vesicles released by cells during activation or apoptosis, which play an important role in cell communication. Relevant studies have shown that extracellular vesicles contain a variety of bioactive substances and participate in infertility related pathophysiological processes by influencing the content of intercellular transmission. Therefore, we reviewed the relationship between extracellular vesicles and male infertility, and expounded the occurrence and potential treatment of male infertility from another perspective.

Comparison of the spermatogenic process in three different mice strains: Swiss, Balb/C and C57BL/6

Many studies have been trying to establish standard protocols for animal experimentation, especially for animal species or strains, to master research variables with high precision. The main mouse strains used in the field of the biology of reproduction are Swiss, Balb/c, and C57BL/6. Since some of the strains show reproduction limitations, such as the size of the litter, the present study aimed to compare their spermatogenic processes to verify differences regarding the testicular parenchyma and germ cell populations, which could explain low offspring production. In addition, the present study provides additional information concerning the testicular parenchyma of such strains, which consequently would help researchers to choose the most suitable strain for reproductive studies. Six adult male mice were used for each of the strains. After euthanasia, the testes were weighed, fixated with Karnovsky fixative, embedded in methacrylate, sectioned, and stained with toluidine blue/sodium borate 1%. Morphometrical analyses from the testicular parenchyma (seminiferous tubules and interstitium) were made using the software ImageJ. Germ and Sertoli cells populations were counted in seminiferous tubules cross-sections at stage I of the seminiferous epithelium cycle. The lowest body and testicular weights were observed in C57BL/6 animals, followed by Balb/c and Swiss, however, the relative testes, parenchyma, and albuginea weights were significantly lower only in C57BL/6. Despite the seminiferous tubules and seminiferous epithelium proportions were lower in Swiss animals, their relative amount related to the body weight was the same among strains. The total number of germ cells was higher in Swiss animals, reflecting higher spermatogenic yield and daily sperm production. Due to the lower relative number of Sertoli cells, the Swiss animals showed the highest Sertoli cell index and support capacity. On the other hand, the lowest pathological indexes regarding the germ cells were observed in Balb/c animals, followed by Swiss and C57BL/6. In the interstitium, the proportion of blood vessels was lower in Swiss mice, while the lymphatic cell proportion was lower in C57BL/6 animals. Moreover, the highest proportions of Leydig cells and macrophages were noticed in Swiss mice, which may indicate increased testosterone levels. Altogether, such observations must be taken into account when choosing any of the studied strains for reproduction studies.

Antifertility and profertility effects of the leaves and seeds of fluted pumpkin: Sperm quality, hormonal effects and histomorphological changes in the testes of experimental animal models / 中西医结合学报

Fluted pumpkin (FP; Telfairia occidentalis) is an edible vegetable, grown in West Africa, that is used in traditional medicine for its regulatory effects on the male gonads. Scientific articles concerning the effects of FP were identified by searching PubMed, PubChem, Scopus, Springer, ResearchGate, Google Scholar and Web of Science; this literature was to better understand the effects of FP seed (FPS) and leaf (FPL) extracts on the testes. Data showed that in experimental animals extracts of FPL and FPS at 1/100 of the lethal dose promoted testis regeneration and improved testosterone concentration and sperm quality, while at higher doses they had antifertility effects. Several extracts of FPS and FPL, including ethanol, aqueous, methanol and hydroethanolic, had protective effects on the testes of study animals at lower doses (≥ 50 mg/kg body weight), but at higher doses (≥ 200 mg/kg body weight) they inhibited hormone synthesis, sperm quality and histomorphological structure, under both normal and disease conditions. The posttreatment effects of FPS on the gonads were reversible in young mature rats and FPS had slight systemic toxic effects. Although, there are inconsistencies in some of the published results, the current evidence suggests that FPS and FPL have both profertility and reversible antifertility effects in experimental animals.

Novel insights into the pathophysiology of varicocele and its association with reactive oxygen species and sperm DNA fragmentation / 亚洲男科学杂志(英文版)

Varicocele has been associated with reduced male reproductive potential. With the advances in biomolecular techniques, it has been possible to better understand the mechanisms involved in testicular damage provoked by varicocele. Current evidence suggests the central role of reactive oxygen species (ROS) and the resultant oxidative stress (OS) in the pathogenesis of varicocele-associated male subfertility although the mechanisms have not yet been fully described and it is likely to be multifactorial. Excessive ROS is associated with sperm DNA fragmentation, which may mediate the clinical manifestation of poor sperm function and fertilization outcome related to varicocele. Testing of ROS/OS and DNA fragmentation has the potential to provide additional diagnostic and prognostic information compared to conventional semen analysis and may guide therapeutic management strategies in individual patient.

Experimental and clinical study on affection of Toxoplasma gondii infection on male reproduction / 中国血吸虫病防治杂志

Objective To study the male reproductive ability of male rats with Toxoplasma gondii ( Tg) infection and investigate the variation of Toxoplasma infection in seminal plasma of infertile patients and explore its mechanism. Methods Thirty SD rats were randomly divided into 3 groups. The rats in the Toxoplasma infection group were administrated intraperitoneally with tachyzoites of Tg. in a dosage of 2 × 10~ 5/ml(2ml) , the rats in the treated group were administered with the same dosage of the tachyzoites and from the second day after the infection they were treated with 200 mg/kg azithromycin for 7 days, and the normal group was given physiological saline. Nine weeks after the infection, the serum sex hormone level, number,vitality, activity and quantity of spermatozoa and activities of enzymes in testa's of the testicular tissues were determined in the male rats. The female rats infected with Tg were matched with normal female rats at a ratio of 1: 2 for one week, and on the 21st day of pregnancy, the number of corpora luteum, sex ratio and the weight, body length and tail length of fetus were measured. The ELISA method was used todetermine the seminal plasma's anti-Tg IgG antibody of the 169 patients with infertility and 35 males with normal fertility. Meanwhile the NO levels in their semina were determined by means of nitric acid reducase. Results The number, activity .vitality, serum level of sex hormones were all lower in the infected rats than those in the normal and treated groups. The number of fetus in the pregnant rats matched with the infected male rats was significantly fewer, but the average body weight, body length, tail length of the fetuses and sex proportion showed no significant difference in comparison with those of the control group. The anti-Toxoplasma gondii antibody positive rate in the masculine infertility patients was 18.35% , being significantly higher than 2. 86% in the normal fertility group(P < 0.05 ). The mean NO level in the semina from the infertility group was (146.68 ± 38. 87) μnol/L , which was significantly higher than (84.92 ± 26.72) μnol/L( P < 0.01) in the fertility group. Conclusion Toxoplasma gondii infection can cause certain influences on the male reproductive ability.

Maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin and the body burden in offspring of long-evans rats

<p><b>OBJECTIVES</b>In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) results in a wide variety of developmental effects in pups at doses much lower than those causing overt toxicity in adult animals. We investigated the relationship between tissue concentrations of TCDD in dams and fetuses and developmental effects on pups.</p><p><b>MATERIALS AND METHODS</b>Pregnant Long-Evans rats were given TCDD at a single oral dose of 12.5, 50, 200, or 800 ng of TCDD or [(3)H]-TCDD/kg bw on gestation day (GD) 15. Dams were sacrificed on GD16 and GD21, and the tissue concentrations of TCDD were measured in dams and fetuses. Pups were sacrificed on postnatal day (PND) 49 and PND63 for males and PND70 for females, and the reproductive effects and tissue concentrations of TCDD were determined.</p><p><b>RESULTS</b>The sex ratio (male/female) on GD21 was significantly reduced at 50 ng TCDD/kg and at 12.5 and 50 ng TCDD/kg at birth, but not at other doses. Delayed puberty was observed in males at 200 ng TCDD/kg and in males and females at 800 ng TCDD/kg. Anogenital distance, testis weight, epididymal sperm count, sperm motility, and ejaculated sperm count were not affected. Estrous cyclicity was not different from that of the control in any treatment group. A dose-dependent decrease in weight of seminal vesicle and prostate on PND49 was observed. Prostate weight was significantly decreased at 800 ng TCDD/kg. At this dose, maternal body burden and TCDD concentration in fetuses were 290 pg TCDD/g and 52 pg TCDD/g on GD16, respectively. Reduced prostate weight is a sensitive and commonly observed endpoint so that the body burdens of dams and fetuses at the LOAEL of this endpoint could be served as the basis for establishing TDI for dioxins.</p>

Maternal Exposure to 2,3,7,8-Tetrachlorodibenzo-\it{p}-Dioxin and the Body Burden in Offspring of Long-Evans Rats

Objectives: In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) results in a wide variety of developmental effects in pups at doses much lower than those causing overt toxicity in adult animals. We investigated the relationship between tissue concentrations of TCDD in dams and fetuses and developmental effects on pups. Materials and Methods: Pregnant Long-Evans rats were given TCDD at a single oral dose of 12.5, 50, 200, or 800 ng of TCDD or [3H]-TCDD/kg bw on gestation day (GD) 15. Dams were sacrificed on GD16 and GD21, and the tissue concentrations of TCDD were measured in dams and fetuses. Pups were sacrificed on postnatal day (PND) 49 and PND63 for males and PND70 for females, and the reproductive effects and tissue concentrations of TCDD were determined. Results: The sex ratio (male/female) on GD21 was significantly reduced at 50 ng TCDD/kg and at 12.5 and 50 ng TCDD/kg at birth, but not at other doses. Delayed puberty was observed in males at 200 ng TCDD/kg and in males and females at 800 ng TCDD/kg. Anogenital distance, testis weight, epididymal sperm count, sperm motility, and ejaculated sperm count were not affected. Estrous cyclicity was not different from that of the control in any treatment group. A dose-dependent decrease in weight of seminal vesicle and prostate on PND49 was observed. Prostate weight was significantly decreased at 800 ng TCDD/kg. At this dose, maternal body burden and TCDD concentration in fetuses were 290 pg TCDD/g and 52 pg TCDD/g on GD16, respectively. Reduced prostate weight is a sensitive and commonly observed endpoint so that the body burdens of dams and fetuses at the LOAEL of this endpoint could be served as the basis for establishing TDI for dioxins.

Biological and clinical research on male reproduction and fertility regulation.

Biological and clinical research on male reproduction and fertility regulation carried at the National Institute of Health and Family Welfare over the past 17 years has been highlighted in this review. Areas of research covered pertains to hormones in relation to sperm maturation and transport; fertilizing ability of spermatozoa under different experimental conditions; agents producing functional sterility; seasonal variations in primate reproduction; male infertility including semen biochemistry, differential diagnosis between obstructive and non-obstructive azoospermia and hormone therapy; vasectomy, reversible vasocclusion and vasanastomosis; and the use of cyproterone acetate and testosterone enanthate in male rhesus monkey and human volunteers for reversible contraception.

Ultrastractural features of the principal cell in the epididymis of the rhesus monkey.

The ultrastructural features of the principal cell in the epididymal epithelium of the monkey epididymis are suggestive of the cell carrying out a dual function of absorption and secretion. Both these functions occur on the luminal surface of the cell as well as on the lateral and basal aspects of the cell which face the intercellular spaces. Transmision Electron Microscopic studies of epididymal tissues following their impregnation with lanthanum nitrate indicated that the intercellular spaces are effectively sealed-off from the luminal space by the apically situated tight junctions between adjoining principal cells. The intercellular spaces are contiguous with the perivascular spaces of the subepithelial blood capillaries. It is suggested that the absorptive and secretory functions occuring on the apical surface of cells may be related to the creation of an appropriate intraluminal milieu for the maturation of spermatozoa while the occurrence of these functions in the intercellular spaces may represent an exchange of substances between the principal cells and the subepithelial capillaries.