Trace elements are important factors in human reproductive health. Among them, special attention is paid to zinc, which is an essential trace element and is necessary for the normal functioning of the male reproductive system and the process of spermatogenesis. The aim of the study was to investigate the association between seminal and serum zinc concentrations and semen quality and reproductive hormone levels in population of Russian young men. The study population consisted of 626 young Russian men (median age 22.5 years), recruited from the general population, regardless of their fertility status. Each participant provided semen and blood sample, information about his lifestyle and ethnicity. Semen quality (sperm concentration, motility and morphology), reproductive hormone levels (testosterone, estradiol, LH, FSH and inhibin B), and serum and seminal zinc concentrations were evaluated. The semen samples were analyzed according to the WHO laboratory manual (WHO, 2010). Serum hormones were measured by enzyme immunoassay, zinc concentrations were determined using spectrophotometry and direct colorimetry without deproteinization. Zinc was present in the seminal plasma in a significantly higher concentration than in the blood serum (median serum Zn concentration was 23.6 μmol/L vs seminal Zn concentration 1571.8 μmol/L). The seminal zinc concentration was positively related to the total sperm count, sperm concentration, progressive motility and normal morphology (Spearman's test: 0.221; 0.286; 0.269; 0.183, respectively, p < 0.001), while the serum Zn concentration was negatively related to serum testosterone and estradiol levels (r = -0.249 and r = -0.096, respectively, p < 0.001-0.05). It was found that the seminal Zn content in men with normal semen quality was higher compared to men with lowered semen quality (means: 6.37 and 5.03 μmol/ejaculate, respectively, p < 0.001). Similarly, the semen volume, total sperm count, sperm concentration, progressive motility, normal morphology and the serum testosterone level in men with the seminal Zn deficiency were lower than in men with the normal seminal Zn content. Based on the results of our population-based study, seminal Zn levels were closely associated with semen parameters in young men, so Zn deficiency may be an important risk factor for lowered semen quality. Seminal Zn determinations should be considered as a useful tool in addition to other parameters in assessing male fertility.

Background: Analysis of sperm morphology defects (amorphous heads, abnormal acrosome, etc.) is useful for estimating the efficiency of spermiogenesis and sperm maturation. An advanced paternal age (more than 40 years) is associated with decreasing sperm count and reduced motility; however, there is little information on the effect of aging relating to sperm morphological defects. Moreover, searching for stable combinations of certain morphological defects in the same sperm can be useful for better understanding spermiogenesis. The aim of the study was to investigate age-related changes in sperm morphology and the prevalence of certain combinations of sperm morphological defects in men from the general population. Methods: Sperm morphology was assessed in 1266 volunteers from the Russian urban general population in different age groups (18–19, 20–24, 25–29, 30–34, 35–40, and over 40 years old). Two hundred sperm were evaluated from each semen sample (about 250 thousand spermatozoa in total). Sperm defects were classified according to the WHO laboratory manual (WHO, 2010). The total percentage of each sperm defect and the frequency of different combinations of sperm morphological anomalies for each age group were counted. Additionally, a similar analysis was performed for the groups of normospermia and pathozoospermia. Results: The frequency of coiled and short sperm tails increased in men over 40 years old compared to younger subjects; however, aging did not affect the percentage of morphologically normal sperm. It was shown that the combination of a misshaped head (amorphous, pyriform, and elongated) with a postacrosomal vacuole, acrosome defect, excess residual cytoplasm, or any anomaly of the midpiece or tail in the same spermatozoon were not random combinations of independent solitary defects. The increased frequency of combinations of coiled tails with amorphous, elongated, or vacuolated heads was observed in men older than 40 years. Sperm morphological defects, such as severely deformed heads (pyriform, elongated, and round) were more common in men with pathozoospermia compared to normospermic subjects. Conclusions: An age-related impairment in sperm morphology was found. Stable combinations of head defects with anomalies in the acrosome, midpiece or tail suggest that these defects may be the result of a general violation in the morphogenetic mechanism.

Background: This is the first large‐scale Russian study describing semen quality and reproductive hormone levels among young men.Objectives: The aim of the study was to compare semen quality and reproductive hormone levels in young men of four cities and three ethnic groups living in the Siberian region of Russia and to find out ethnic or environmental reasons for regional differences.Materials and methods: The study population consisted of 1291 young men from Novosibirsk, Kemerovo, Ulan‐Ude, and Yakutsk, including 1013 men of three most numerous ethnic groups: Slavs, Buryats, and Yakuts. Each participant provided one sperm and blood sample, information about lifestyle and ethnicity. Anthropometric parameters, semen quality and reproductive hormone levels, were evaluated.Results: Significant regional and ethnic differences were detected for semen and reproductive hormone parameters. Median sperm concentrations in Novosibirsk, Kemerovo, Ulan‐Ude, and Yakutsk were 54.6, 39.9, 34.7, 33.1 × 10⁶/ml; total sperm counts—202.5, 138.7, 97.9, 93.4 × 10⁶; percentages of morphologically normal spermatozoa—7.8%, 6.5%, 6.3%, 5.0%, respectively. Median sperm concentrations in Slavs, Buryats, and Yakuts were 43.7, 37.0, 30.6 × 10⁶/ml; total sperm counts—150.0, 102.3 and 74.8 × 10⁶; percentages of morphologically normal spermatozoa—6.8%, 6.8%, 4.8%, respectively.Discussion: The young men in Novosibirsk and Kemerovo, populated by Slavs, had a higher semen quality compared to Ulan‐Ude and Yakutsk, populated by Buryats and Yakuts, apparently due to the higher testicular function in Slavic compared to Asian ethnicity. Impaired spermatogenesis in young men in Kemerovo compared to Novosibirsk, located in the same climatic zone and having a socio‐cultural and ethnic identity, may be due to the influence of a polluted environment.Conclusion: The findings suggest that ethnic composition and environment may be responsible for regional differences in semen and reproductive hormone parameters.

Male infertility is a multi-factorial and multi-genetic disorder, and the prevalence of male infertility in the world is estimated at 5–35%. The search for the causes of male infertility allowed for identifying a number of genetic factors including a single X-linked gene of the androgen receptor (AR), and some of its alleles are assumed to negatively affect male fertility. Our aim was (1) to study the variability of the length of CAG repeats of the AR gene and possible associations in the AR CAG genetic variants with semen quality and reproductive hormone levels in a population-based cohort of men and (2) to estimate distributions of AR CAG repeat alleles and associations with semen parameters in different ethnic subgroups. The cohort of 1324 young male volunteers of different ethnicities (median age 23.0 years) was recruited from the general population of five cities of the Russian Federation, regardless of their fertility status. Semen quality (sperm concentration, motility and morphology), reproductive hormone levels (testosterone, estradiol, LH, FSH and inhibin B) and trinucleotide (CAG) n repeat polymorphism in exon 1 of the AR gene were evaluated. The semen samples were analyzed according to the WHO laboratory manual (WHO, 2010), serum hormones were measured by enzyme immunoassay, and the AR CAG repeat length was analyzed by direct sequencing of leukocyte DNA. The median AR CAG repeat length in men of our multi-ethnic population was 23 (range 6–39). In the entire study population, a significant difference (p ≤ 0.05) was found in the frequency distribution and the mean values for the CAG repeat length between the groups with normal (23.2 ± 3.3) and impaired semen quality (23.9 ± 3.2). Additionally, we demonstrated that the total sperm count, sperm concentration, progressive motility and normal morphology were lower in the category of long CAG repeats (CAG ≥ 25) compared with those in the category of short CAG repeats (CAG ≤ 19); however, hormonal parameters did not differ between the long and short CAG categories, with the exception of estradiol. Significant differences were observed in the AR CAG repeat length between the most common ethnic cohorts of Slavs (Caucasians), Buryats (Asians), and Yakuts (Asians). The Buryats and Yakuts had a higher number of CAG repeats than the Slavs (medians: Slavs—23; Buryats—24; Yakuts—25). The range of alleles differed among ethnicities, with the Slavs having the largest range (7–36 repeats, 24 alleles total), the Yakuts having the smallest range (18–32 repeats, 14 alleles total) and the Buryats having the middle range (11–39 repeats, 20 alleles total). The longer CAG repeats were associated with an impaired semen quality within the Slavic (CAG ≥ 25) and Buryat (CAG ≥ 28) groups, but this effect was not found in Yakuts. Hormonal parameters did not differ between the three CAG repeat categories in men of all ethnic groups. This is the largest Russian study of the distribution of AR CAG repeats and the search for association between length of AR CAG repeat tract and impaired spermatogenesis in men from the general population. Our results confirmed the association of longer CAG repeats with a risk of impaired semen quality, but this association can be modified by ethnic origin. Identification of the number of AR CAG repeats can be an effective tool to assess the risk of male subfertility and the control of androgen hormone therapy of reproductive diseases.

Handling is a stressor for blue foxes. The influence of preterm handling (1 min daily) of vixens was investigated in 68, 10-day-old cubs, 34 male and 34 female. Body, gonadal and pituitary weight, ano-genital distance, gonadal testosterone and oestradiol content and in vitro production, and pituitary LH content were measured in all cubs. The gonads were frozen or incubated in vitro with, or without, added hCG (2.5 IU per sample). The gonadal incubates and homogenates were analysed for testosterone and oestradiol by radioimmunoassay and the pituitary homogenates for LH by immunofluorometric assay. The results indicate that neonatal fox gonads actively produce steroids and that there are significant sex differences in basal steroid production and response of the gonads to hCG, and in pituitary LH content. Maternal stress resulted in a significant reduction of morphometric and hormonal measures of the reproductive system in neonatal blue foxes, with more drastic effects in female cubs. Gonadal weights were lower in cubs of both sexes from stressed vixens (65.7 4.3 v . 50.6 1.8 mg for the ovaries and 23.2 1.0 v . 17.7 1.0 mg for the testes, control v . stressed animals, P <0.01). The ano-genital distance in female offspring of stressed vixens was reduced (1.1 0.04 v . 0.9 0.03 cm, P <0.01). Basal ovarian oestradiol and testosterone production were decreased in cubs from prenatally stressed animals in comparison with controls (43.5 3.5 v . 32.6 3.7 pg ovary–1 h–1 and 0.40 0.16 v . 0.12 0.03 ng ovary–1 h–1, P <0.05). Prenatal stress did not affect either pituitary weights or LH content in either sex. There were no significant differences in ano-genital distance, testicular content of testosterone, or in vitro testosterone production between control and treated male cubs. In conclusion, these findings suggest that prenatal handling stress impaired the neonatal reproductive development of the female offspring, but had no marked effects on males. Sex-specific effects of prenatal handling stress on the reproductive development in foxes may be linked with the gender differences in responses of the hypothalamus–pituitary–adreno-cortical axis to stress conditions in this species.