Associations of CAG repeat polymorphism in the androgen receptor gene with steroid hormone levels and anthropometrics among men: the role of the ethnic factor

Androgens are required for stimulation and maintenance of skeletal growth and bone homeostasis. Physiological functions of androgens are mediated through the androgen receptor (AR). The androgen receptor gene AR has a polymorphic trinucleotide CAG repeat and the length of AR CAG repeats determining the sensitivity of bone tissue to androgens is associated with skeleton formation and body proportions. This study aimed to investigate the relationship between AR CAG repeat polymorphism, circulating sex steroid hormones and the anthropometrics in males of different ethnic origins. Male volunteers of three ethnic groups (Slavs, Buryats, Yakuts) from urban Russian populations were recruited in a population-based study (n = 1078). Anthropometric indicators (height, arm span, leg length, the length of 2 and 4 digits of both hands) were measured and the following anthropometric indices were calculated: the ratio of height to leg length, the ratio of arm span to height, the ratio of lengths of second to fourth digit of the hand. Serum testosterone and estradiol were determined by enzyme immunoassay. Genotyping of the AR CAG repeats was performed using fragment analysis and capillary electrophoresis. Ethnic differences in all anthropometric and hormonal indicators have been established, with higher anthropometric indicators in Slavs than Buryats, and in most cases higher than in Yakuts. The testosterone level was higher among Slavs compared to Buryats, but did not differ from Yakuts; the estradiol level was lower among Slavs compared to Buryats, who did not differ from Yakuts. Buryats and Yakuts had a higher number of CAG repeats than Slavs (medians: Slavs, 23; Buryats, 24; Yakuts, 25). Positive correlations were found between the length of AR CAG repeats and estradiol levels in Buryats and testosterone levels in Yakuts, while longer CAG repeats were accompanied by higher estradiol levels in Buryats and testosterone levels in Slavs and Yakuts. Ethnic-specific correlations have been established between the steroid hormone levels and some anthropometric indicators in all ethnic groups. Available data suggest that the ethnic-specific associations of AR CAG repeats with anthropometrics can be mediated by sex steroid hormones as important regulators of skeletal growth and bone homeostasis.

Association of Overweight and Obesity with Semen Parameters and Metabolic and Hormonal Status in Young Men

We evaluated possible associations of overweight and obesity with semen parameters, sperm DNA fragmentation (SDF), and different indicators of metabolic and hormonal status in young men (n=226, mean age 22.5 years). Overweight and obese men were found to have a significant deterioration of metabolic health, reduced total sperm count and concentration, serum testosterone, and inhibin B levels, and increased serum leptin and seminal zinc levels in comparison with men with normal weight, although sperm DNA fragmentation, motility, and morphology did not change. In overweight and obese men, increased seminal zinc content appears to perform a protective function via reduction of oxidative stress caused by excess body fat. It is assumed that in the absence of individual lifestyle correction and weight loss for a long time, obese subjects are not protected from the development of reproductive comorbidities, in particular, subfertility and infertility.

Steroid Hormones in Seminal Plasma: the Relationship with Sperm Quality

The purpose of this study was to find out whether the seminal testosterone and/or estradiol levels could serve as prognostic criteria for normal spermatogenesis and whether they are able to characterize the sperm pathology. The study involved healthy young male volunteers (n=269); serum and seminal steroid hormones were measured; the sperm concentration, mobility, and morphology were evaluated. The results indicate that the seminal testosterone concentration is lower (p<0.05) and the seminal estradiol is higher than the corresponding parameters in the serum (p<0.05). The seminal testosterone and estradiol concentrations negatively correlated with the sperm concentration, and the seminal estradiol concentration was higher in pathozoospermic than in normospermic men (p<0.05). It is assumed that the seminal estradiol level can be an indicator of sperm quality and serve as a biological predictor of normal spermatogenesis; in addition, this parameter can be used for diagnostic purposes in patients with impaired spermatogenesis induced by excess of estrogens.

A bioinformatic search for correspondence between differentially expressed genes of domestic versus wild animals and orthologous human genes altering reproductive potential

One of the greatest achievements of genetics in the 20th century is D.K. Belyaev’s discovery of destabilizing selection during the domestication of animals and that this selection affects only gene expression regulation (not gene structure) and inf luences systems of neuroendocrine control of ontogenesis in a stressful environment. Among the experimental data generalized by Belyaev’s discovery, there are also f indings about accelerated extinc tion of testes’ hormonal function and disrupted seasonality of reproduction of domesticated foxes in comparison with their wild congeners. To date, Belyaev’s discovery has already been repeatedly conf irmed, for example, by independent observations during deer domestication, during the use of rats as laboratory animals, after the reintroduction of endangered species such as Przewalski’s horse, and during the creation of a Siberian reserve population of the Siberian grouse when it had reached an endangered status in natural habitats. A genome-wide comparison among humans, several domestic animals, and some of their wild congeners has given rise to the concept of self-domestication syndrome, which includes autism spectrum disorders. In our previous study, we created a bioinformatic model of human self-domestication syndrome using differentially expressed genes (DEGs; of domestic animals versus their wild congeners) orthologous to the human genes (mainly, nervous-system genes) whose changes in expression affect reproductive potential, i. e., growth of the number of humans in the absence of restrictions caused by limiting factors. Here, we applied this model to 68 human genes whose changes in expression alter the reproductive health of women and men and to 3080 DEGs of domestic versus wild animals. As a result, in domestic animals, we identif ied 16 and 4 DEGs, the expression changes of which are codirected with changes in the expression of the human orthologous genes decreasing and increasing human reproductive potential, respectively. The wild animals had 9 and 11 such DEGs, respectively. This difference between domestic and wild animals was signif icant according to Pearson’s χ2 test (p < 0.05) and Fisher’s exact test (p < 0.05). We discuss the results from the standpoint of restoration of endangered animal species whose natural habitats are subject to an anthropogenic impact.

[An influence of zinc on male infertility]

Trace elements play an important role in human health. They are involved in growth, development, reproduction, and other physiological functions. Among them, special attention is paid to zinc, which is an essential trace element required for the normal functioning of many organ systems. Experimental data have been accumulated indicating a significant role of zinc in the functioning of the male reproductive system and the spermatogenesis. Zinc concentration in seminal plasma is considerably higher compared to those in other body fluids. In contrast to its serum concentration, seminal zinc level is associated with the sperm concentration, motility and morphology. Under dietary deficiency, Zinc supplementation can significantly increase the ejaculate volume, sperm motility and morphology and improves overall sperm quality in infertile patients. Zinc, being a structural element of a large number of different macromolecules and enzymes, shows antioxidant, antibacterial and antiapoptotic properties in the testes. It should be considered as one of the trace elements with great potential for the prevention and treatment of male infertility and subfertility. The aim of this review is to analyze current publications and summarize information about the effect of zinc on male fertility and its properties related to sperm quality and successful fertilization.

[Candidate SNP-markers altering TBP binding affinity for promoters of the Y-linked genes CDY2A, SHOX, and ZFY are lowering many indexes of reproductive potential in men]

Репродуктивный потенциал – уровень физического и психического состояния организма, позволяю- щий при достижении социальной зрелости воспроизводить здоровое потомство. В узком биомедицинском смыс- ле определение включает комплекс функциональных показателей репродуктивной системы, но в более широком смысле его можно рассматривать как совокупность физиологических, поведенческих, адаптивных, ментальных, ан- тропометрических и генетических характеристик особи, способствующих размножению. Целью настоящей работы было расширить область применимости созданного ранее Web-сервиса SNP_TATA_Z-tester для поиска кандидатных маркеров однонуклеотидного полиморфизма (SNP) на хромосоме Y человека, связанных с мужским репродуктив- ным потенциалом (МРП). В поиске кандидатных SNP-маркеров для МРП мы сосредоточились на генах хромосомы Y человека. Изучены 35 SNP в промоторах генов CDY2A, SHOX и ZFY, представляющих все три типа генов хромосомы Y человека: уникальный, псевдоаутосомный и паралог гена хромосомы X человека соответственно. Предсказаны 11 кандидатных SNP-маркеров ослабления МРП из-за изменения сродства TATA-связывающего белка (TBP) к этим промоторам. Выборочно верифицированы in vitro величины сродства «TBP-промотор», предсказанные в этой рабо- те. Установлена достоверная корреляция (r = 0.94, p < 0.005) между ними и результатами измерения in vitro сродства ТВР человека к олигонуклеотидам, идентичным сайтам ТВР-связывания исследуемых промоторов. Проведя поиск в базе данных PubMed по ключевым словам, мы нашли клиническое описание патологических состояний человека, соответствующих изменению экспрессии генов, несущих предсказанные нами кандидатные SNP-маркеры. Среди них оказались такие патологии, как нарушение сперматогенеза (ZFY: rs1388535808 и rs996955491), задержка поло- вого созревания (CDY2A: rs200670724), нарушения эмбриогенеза (SHOX: rs28378830) и непропорционально низкий рост с деформациями Маделунга (SHOX: rs1452787381). Они свидетельствуют, что в случае SNP-промоторов генов хромосомы Y человека следует ожидать изменений широкого круга показателей МРП, выходящих далеко за рамки генетического контроля собственно мужской репродуктивной функции.

[Epidemiological studies of the male reproductive potential: sperm quality as a marker of reproductive health]

Currently, the global demographic crisis in industrialized countries, including Russia, is accompanied by a decrease in the reproductive potential of human populations. In different regions of the world, a decrease in male fertility has been observed that expressing in poor semen quality, increasing in the proportion of male factor in infertile couples and the growth of congenital anomalies of the male reproductive system, resulting to infertility. The observed negative trends in a range of male reproductive problems highlighted the global problem of maintaining mens health, as well as raised the question of the causes of this phenomenon. Taking into account the increasing risks associated with reproduction of humanity, epidemiological studies of male fertility have been started in various countries of the world. The purpose of this review is to analyse epidemiological studies of male fertility, regional and ethnic differences in biological indicators of male fertility. The review provides information on regional and ethnic differences in male fertility in Western Europe, the United States, China, Japan and other countries. Based on our review of epidemiological data we can conclude that the region of residence and ethnicity are important determinants of the male reproductive potential, which can have a significant impact on its variability. Traditional methods of population studies of male fertility are considered, based on which time trends, regional and ethnic differences in the male reproductive potential are studied, and adequate information about the prevalence and causes of male infertility and subfertility can be obtained.

Semen quality and diversity of morphological sperm abnormalities in bulls: breed and strain effects

At present great attention is paid to studying genetic regulation of farm animal adaptations to environmental conditions. This problem is very important due to a wide expansion of highly productive cattle breeds created in Europe and North America. However, until the present no investigation of changing semen quality in bulls of imported breeds during their adaptations to environmental conditions of Western Siberia has been conducted. The aim of this study was to investigate semen quality peculiarities and the diversity of morphological sperm abnormalities in bulls of imported and local breeds kept in the environmental conditions of the southern part of Western Siberia. We determined sperm concentration, sperm count, and rate of sperm with progressive motility and percentage of morphologically normal spermatozoa. The rate of sperm abnormalities according to Blome’s classifcation was determined too. It was found that the mean values of sperm concentration, sperm motility and percentage of morphologically normal spermatozoa in the bulls investigated were similar to those in bulls kept in European countries. Inter­breed differences in these parameters were not found. However, bulls of the Red Danish, Angler, and Simmental breeds had a higher percentage of misshapen sperm head and pyriform sperm head than bulls of the Black­White breed. An inter­strain difference in sperm motility in bulls of the Black­White breed was observed. It was found that bulls of Reflection Sovereign 198998 strain had lover sperm motility than bulls of Wis Burke Ideal 1013415 strain. No inter­strain differences in sperm production, percentage of morphologically normal spermatozoa and rate of main sperm abnormalities were found. Thus, it has been found that the environmental conditions of the southern part of Western Siberia do not seriously affect the sperm production, sperm motility or percentage of morphologically normal spermatozoa in bulls. However, the increased rate of misshapen and pyriform sperm heads in the bulls of the foreign breeds points to a need to study sperm DNA fragmentation.

SPERM QUALITY IN RATS PREDISPOSED TO THE MANIFESTATION OF CATATONIC REACTIONS

Catatonia is a psychopathological syndrome displayed as a motor disorder. Catatonia is a sign of many menthal disorders, particularly schizophrenia and depression, with a wide disrtibution in the human population. The GC (“genetic” and “catatonia”) rat strain was obtained from the Wistar rat strain by a long selection (78 generations) for the catatonic type of reaction and is a model of schizophrenic and depressive disorders in humans. It is known that selection for behavior including catatonic reactions results in neuroendocrine, reproductive and morphological changes in animals. However, the influence of selection for a catatonic reaction on the spermatogenic function of testes had not been studied. The aim of this study was to conduct a comparative investigation of sperm quality in rats of the GC and the Wistar strain. The epididymal sperm parameters (sperm count, sperm motility, sperm morphology) were measured, and body, testes and epididymal weight were determined at puberty (50 day of life) and at adulthood (90 day of life). The litter size of the GC and Wistar rats was determined. It was found that adult GC rats had a lower sperm count, sperm motility, testis weight, epydidymal weight and litter size compared to adult Wistar rats. However, at puberty, GC rats had a higher sperm count than the Wistar strain. Interstrain differences in sperm morphology were not found. It has been assumed that the changes of spermatogenic parameters in response to selection for catatonia are caused by changing the ontogenic pattern of testosterone secretion. In conclusion, the hereditary predisposition to catatonic reaction is associated with impaired sperm parameters in adult rats that reduces their chance to reproduction. The GC rat strain can be a perspective model for investigation of the relationship between the hereditary predisposition to catatonia and spermatogenesis

[Effects of smoking and alcohol consumptionon reproductive and metabolic indicators in young men in western siberia]

INTRODUCTION

Smoking and alcohol consumption remain widespread throughout the world, including Russia. Recently, due to the increase in male infertility and subfertility, special attention has been paid to the effects of smoking and alcohol on the reproductive health of young men. The aim of this study was to assess the effects of smoking and moderate alcohol consumption on spermatogenesis, reproductive hormone levels and metabolic status in young men living in Western Siberia (Novosibirsk).

MATERIALS AND METHODS

One hundred thirty-three volunteers (mean age 21.1+/-0.3 years) were tested for the sperm concentration, the proportion of mobile and morphologically normal spermatozoa in the ejaculate, blood serum levels of follicle-stimulating and luteinizing hormones, prolactin, testosterone, estradiol, inhibin B, triglycerides, total cholesterol, high and low density lipoprotein cholesterol, glucose and uric acid.

RESULTS

and conclusions The studied lifestyle factors were found to have no effects on spermatogenesis. Smoking more than 10 cigarettes per day and a moderate frequency of alcohol consumption (up to 1 time per week) was associated with higher blood serum testosterone levels and engaging in more frequent sexual contacts compared to non-smoking and non-drinking men. Drinking alcohol more than once a week and smoking more than 8 cigarettes per day was associated, along with the increase in testosterone levels and the frequency of sexual contacts, with lower levels of follicle-stimulating hormone and higher serum triglyceride levels. Thus, in young men, frequent drinking and smoking can alter the hormonal and metabolic balance, which, as the duration of the exposure and the strength of the factors increase, will increase the risk of reproductive disorders.

[Sperm DNA fragmentation: association with semen parameters in young men]

AIM

Abnormal sperm DNA integrity is an important risk factor for male infertility. The aim of this work was to examine sperm DNA fragmentation in a cohort of young male volunteers (n=111; age 21.0+/-0.2 years) from the general population and establish the association between the level of sperm DNA fragmentation and sperm functional parameters.

MATERIALS AND METHODS

Sperm DNA fragmentation index (DFI) was determined by SCSA (sperm chromatin structure assay) using flow cytometry. Standard semen parameters (concentration, motility, and morphology) were evaluated according to the WHO guidelines (2010).

RESULTS

and conclusions. In the study cohort, 79.0%, 12.4% and 8.6% of men had normal (DFI<15%), borderline (15 less or equal DFI<27%) and high (DFI more or equal 27%) levels of fragmentation, respectively. Men with impaired spermatogenesis had greater IDF values (14.53+/-1.43%) than men with normal semen parameters (8.88+/-0.77%, p<0.05). There was a statistically significant negative correlation between IFD and ejaculate concentration (r=-0.21, p<0.05), fractions of mobile (r=-0.41, p<0.05) and morphologically normal sperm (r=- 0.34, p<0.05). Testing sperm DNA fragmentation using SCSA technique can be employed in epidemiological studies of male fertility.

[TESTICULAR FUNCTION AND LIPID METABOLISM IN MALE MICE WITH HEREDITARY PREDISPOSITION TO OBESITY]

Parameters of spermatogenesis, androgen status and lipid metabolism (amount of abdominal fat, cholesterol and triglycerides plasma levels) in male mice with the mutation yellow at the locus agouti (Ay mice), which results in obesity after puberty were studied. Their lean littermate's mice of standard C57BL/6J strain genotype (a/a mice) were used as a control. At the age of 15 and 30 weeks the body weight, triglyceride levels, and at the age of 30 weeks - abdominal fat mass in Ay males were higher than that of a/a males. These data confirm the development of obesity and disturbance of lipid metabolism in Ay males. There were no changes in the number of sperm in the caudal epididymis, the proportion of mobile and morphologically abnormal sperm, the concentration of testosterone and its content in the testes in Ay mice at the reproductively active period (age 15 and 30 weeks). It is assumed that the ectopic expression of agouti protein in Ay males may be involved in the protection of the testicular function from the negative impact of obesity.

INTERSTRAIN DIFFERENCES IN THE PARAMETERS OF SPERMATOGENESIS IN INBRED MICE

The aim of the present work was a comparative study of basic parameters of spermatogenesis in mice of inbred PT (n=99) and CBA/Lac (n=81) strains, starting with the puberal period of development until Day 80. The number of spermatozoa was measured in the caudal portions of both epididymides (epididymal reserve), morphological characteristics and spermatozoa motility were evaluated, and body, testes and epididymal weight was determined. Starting from puberty and thereafter, it was found that CBA/Lac males as compared with RT mice had lower testicular mass and epididymal spermatozoa number. However, spermatozoa functional capacity of CBA/Lac males was higher as compared to that of PT mice, since starting with the puberal period, they were characterized by a lower frequency of abnormal forms, and in the post-puberal period — by higher relative concentrations of motile spermatozoa. Thus, in the males of laboratory mice studied, the interstrain differences in the key parameters of spermatogenesis related to fertility, began to emerge in the puberal period, and their interstrain variability may have a compensatory character.

Reproductive Health and Peculiarities of Lipid Peroxidation-Antioxidant Defense System in Men of the Main Ethnic Groups of the Baikal Region

Quality of sperm and some parameters of LPO reflecting primary and end stages of oxidation and levels of α-tocopherol and total antioxidant activity were studied in ejaculate samples from 130 men (mean age of 24 years) living in Ulan-Ude, Buryatia Republic. All participants took a part in survey and were examined by an andrologist. The observed peculiarities of LPO and antioxidant defense in Russian men, such as decreased level of substrate supply for the processes of LPO and α-tocopherol, attest to specificity of metabolic processes and development of compensatory reactions of the organism under physiological conditions. LPO processes were more active in Buryat men, which can indicate exposure of cell membranes to toxic oxygen species. However, the observed in these patients significant increase in α-tocopherol concentration reflects adequate functioning of the adaptive and protective mechanisms of the body.

[Parental Care and Testosterone Secretion in Forest Rodent Males: Sensitization and Androgenic Stimulation of Parental Behavior]

The reaction of males of three forest rodent species (Myodes clethrionomys, M. rutilus, Apodemus uralensis) to young animals in comparison with their dimensional characteristics and androgenization level was studied. Demonstration of parental care was detected in males of two vole species (M. clethrionomys and M. rutilus) in case of regular contacts with them (sensitization effect). It was demonstrated that the testosterone concentration in the blood serum, as well as the testosterone content in the testicles of the M. clethrionomys males (demonstrating the parental care), was higher than in the sample of males inclined to infanticide. An increased testosterone content in the testicles and blood serum was also found in the M. rutilus males that had contact with young animas. Neither demonstration of parental care nor significant differences in the testosterone concentration in the testicles and blood serum were detected in the A. uralensis males.

[THE OPTIMAL CONDITIONS OF STORAGE OF SPERMATOZOA FOR ANALYSIS OF DNA FRAGMENTATION]

The analysis of fragmentation of DNA of spermatozoons using technique of flow cytometry to evaluate male fertility more and more often begins to be applied in clinical diagnostic. However, development of optimal protocol of storage and preparation of spermatozoons for analysis still is at the stage of experimental elaboration. The studv was carried out to analyse effect of different conditions of preparation of ejaculate for adequate evaluation of index of fragmentation of DNA of spermatozoons using sperm chromatin structure assay technique. The sampling consisted of 20 patients of the Krasnoyarsk center of reproductive medicine. The sperm chromatin structure assay technique was applied to evaluate index of fragmentation of DNA of spermatozoons in fresh native ejaculate and after storage of spermatozoons under different temperature (37, 25 and 4 degrees C) and duration (1-2 and 1-3 days) and conditions of storage (-20 or -70 degrees C) of frozen spermatozoons (as native ejaculate or in TNE-buffer). It is demonstrated that index of fragmentation of DNA of spermatozoons has no significant alterations in ejaculate stored under 4 degrees C during 48 hours. In case of storage of ejaculate under 25 or 37 degrees C index of fragmentation of DNA of spermatozoons significantly increases already after first day of storage. The incubation of ejaculate under 37 degrees C results in increasing of index of fragmentation of DNA of spermatozoons already after first hour. The individual differences are established related to degree of increasing of index of fragmentation of DNA of spermatozoons because of impact of studied temperatures of ejaculate incubation. The storage of spermatozoons under temperature of - 20 and -70 degrees C in native ejaculate or in TNE-buffer has no effect of index of fragmentation of DNA of spermatozoons with measurement during 1-2 hours. Therefore, storage and transportation of native ejaculate under 4 degrees C during 1-2 days or in frozen condition under temperature of -20 degrees C or -70 degrees C can be recommended for adequate evaluation of level of fragmentation of DNA of spermatozoons.

REGIONAL PECULIARITIES IN SEMEN QUALITY AND SERUM HORMONAL CONCENTRATIONS OF CITIZENS FROM YAKUTIA

The objective of the present study was to evaluate sperm quality and reproductive hormonal level in an unselected population of men who were permanent residents of the Yakutsk city and compare the semen and hormonal parameters with the World Health Organization (WHO, 2001) recommended normal values and the results from other countries. A total of 145 men (mean age 24 years) agreed to be included in the study. All the volunteers completed a questionnaire, received a general and reproductive health examination by an andrologist, gave semen and blood samples. There are no differences between Yakut and Slavs in anthropometric, hormonal or sperm measures, but height and ejaculate volume were higher in Slavs than Yakut men. The data obtained indicated high frequency of suboptimal quality of sperm in males of both nations from this Siberian region in comparison with other Russian regions or European countries.

[Level of DNA fragmentation in human sperm cells in varicocele and prostatitis]

Varicocele and prostatitis are the most common andrological diseases, which may be accompanied by a decrease in the production of sperm cells, the deterioration of their quality and increased risk of infertility. This work was aimed to the evaluation of sperm DNA fragmentation index (DFI) and main indices of sperm fertility (concentration, motility and morphology), and the relationship between these parameters in the men of active reproductive age suffering from prostatitis or varicocele. Assessment of sperm DNA fragmentation was performed by SCSA (sperm chromatin structure assay) using flow cytometry; sperm parameters were evaluated according to WHO recommendations. It was shown that men with prostatitis (n = 9) and varicocele (n = 22) had significantly higher DFI compared with men in the control group (n = 22). Negative influence of these diseases on the concentration and the percentage of motile sperm cells in the ejaculate was revealed. These data suggest that the deterioration in the quality of semen in varicocele and prostatitis may be caused not only by pathospermia, but also, at least partially, by violation of the integrity of the sperm DNA. Evaluation of sperm DNA fragmentation can be recommended for use in laboratory diagnostics for prediction of fertility in infertile men.

[Social domination and reproductive success in male laboratory mice (Mus musculus)]

The goal of the present study was to evaluate effect of social status and genotype on success of reproduction of male laboratory mice with use of ethological model of social hierarchy of "minimal socium". The model represents the paired maintenance of two male mice of different genotype (PT and CBA/Lac). The mice lived for 30 days in one experimental cage males, two females of the DD/He strain were supplemented. Regardless of genotype, the dominants became fathers more often than the subordinants and got more progeny. It was established that in subordinates there did not occur the complete suppression of fertility. This is suggested to allow them to realize the genetical contribution to the next generation and to remain in the gene pool of population.

[Testicular testosterone production in male mice of inbred strains PT and CBA/Lac after a long-term period of stable social hierarchy]

Social dominance can alter testicular testosterone production, although there is pronounced variability in the relationship between social status and pattern of the testosterone response. The study designed to investigate how a long-term period of stable social hierarchy effects on testicular testosterone production in male mice of inbred strains PT and CBA/Lac. Paired males of different genotypes were housed together for 32 days beginning 38 day of age. Dyadic interactions of males generated dominance-subordination relationships during the first day after a social group has been produced and the social rank of each opponent was assessed by asymmetry in agonistic behaviour. Serum level of testosterone and its testicular content were evaluated in male mice of both inbred strains at 70 day of age after pair housing. Control animals were age- and genotype-matched single males that were housed in conventional cages. After a long-term period of pair housing, the serum testosterone level and its testicular content in males of both PT and CBA/Lac strains were not significantly different from the control. There were no significant differences in androgenic parameters between social ranks in male mice of both strains. The results indicate that in laboratory mice the pattern of testicular testosterone response to social hierarchy determined by a social situation, for example, a stability of social interactions, when the importance of aggressive competition for rank is minimal.

Changes in hormonal and metabolic status in men of an ethnic group Komi with overweight and obesity

The aim of this study was to compare hormonal, anthropometric and metabolic parameters in men of the komi ethnic group with (n=23, BMI ≥25 kg/м2) or without (n=39, 18.4≤BMI 25 kg/м2) obesity. Totally 62 males living in Komi Republic were included in the study. It has been established that obesity was accompanied by an increase in serum concentrations of cholesterol and low density lipoprotein cholesterol in comparison with control group indicating metabolic disturbance. The data shows the significant effect of BMI on testosterone and FSH serum concentration, but not on LH, estradiol, thyrotrophic hormone, thyroxin and triiodthyronin levels. Overweight and obese men had lower circulating testosterone and higher FSH level in comparison with the controls. The reproductive hormone changes in overweight and obese men can result in deleterious effects on sexual functions including erectile dysfunction, reduced libido and alteration in spermatogenesis

[Parental care and testosterone in males of the bank vole (Myodes glareolus): sensitization and androgenic stimulation of parental behavior]

The relationship between parental responsiveness of bank vole males and their body weight, testes mass, and plasma and gonadal testosterone levels were examined. Two groups of voles were studied: Group I consisted of 14 breeding pairs where females gave birth to young within a month after formation of pairs, and Group II represented 13 pairs without offspring and signs of pregnancy in females. Males in Group I, unlike those in Group II, had contact with pups before the tests on parental responsiveness. In Group I, males were found to have larger testes and to exhibit a higher level of care-giving activity (pup retrieval) as compared to males in Group II. Both the plasma and gonadal testosterone levels in males exhibiting pup retrieval were revealed to be significantly higher than those for males exhibiting infanticide. Thus, promiscuity, competition for receptive females, and a higher level of testosterone secretion, which are characteristic of bank vole males during the breeding season, are not out of the realm of possibility of the males that care for young. Our findings suggest that factors promoting parental responsiveness in bank vole males are sensitization due to contact with pups and an increase in testosterone secretion. Obviously, there is a need to reexamine the role that testosterone plays in regulating rodent parental behavior.

[Growth and development peculiarities of testicles in inbred mice lines PT and CBA/Lac]

The goal of this study is to perform a comparative genetic investigation of testicle development during the postpubescence period (from days 70 to 90 of life) in the inbred mice lines PT and CBA/Lac. Interlinear differences in the body and testicular weight, serum testosterone concentration, number of epididymal spermatozoa, area of testicular epithelium, semeniferous tubule lumen, and insulae of Leydig cells were analyzed. It was found that the morphological and histomorphometric parameters of testicles in males from the PT line compared to the males of the CBA/Lac line did not reach a definitive stage with the end of the postpubescence period and kept on developing until day 90 of life. Therefore, genetic differences remain in the postpubertal testicular development of laboratory mice.

[Phenotypic variation of spermatogenesis and a search for associations with genetic polymorphism in 13 inbred mouse strains]

Adult mice of the BALB/cLac, PT, CBA/Lac, DD/He, A/He, SWR, NZB, GR, DBA/2J, CC57Br, C57 B1/6J, A/Sn, and YT inbred strains were tested for the count, motility, and morphology of sperms from the caudal region of the epididymis. The protein-coding regions of the cytochrome P450 aromatase (CYP19a1), estrogen receptor 2 (ESR2), steroidogenic factor 1 (Nr5a1), and sex-determining (Sry) gene were sequenced. A substantial genetic heterogeneity for the genes was observed, as well as a phenotypic variation in spermatogenetic parameters, but the variation was rather discordant. The specifics of the interstrain variation in spermatogenetic parameters indicated that a physiological compensatory mechanism increases certain spermatogenetic parameters when other ones are low to maintain male fertility at a level sufficient for successful reproduction. For instance, a high sperm production compensated for a low sperm motility in DD/He males. In the issue of the protein-coding regions sequencing of the analyzed genes, 16 various mutations were observed. The decreases in proportion of motile sperms and in their velocity were attributed to mutations (I63T and W133L) of the Sry gene in the DD/He strain.

Modification of the testicular function in laboratory male mice during social interactions: effect of female presence

The count of spermatozoa in both caudal epididymides, percentage of abnormal spermatozoon heads and of mobile spermatozoa, body weight, weights of the testes and caudal epididymides were evaluated in adult inbred males (PT and CBA/Lac) kept with females for 5 days. Male mice of the same genotypes and age separated from females served as controls. In males kept with females, the weights of the testes increased in PT male mice, the percentage of rapidly mobile spermatozoa increased in CBA/Lac mice, and body weights decreased in males of both genotypes. The morphometric and spermatogenic parameters in laboratory mice were modulated by the presence of a female, but the effect was determined by the male genotype.

[A role of long-term social interactions in the control of spermatogenesis in male mice of inbred strains PT and CBA/Lac]

Social hierarchy in the animal community is a structure of behavior relations when members of a social group vary in their ability to acquire resources in the presence of others. The aim of our study was to investigate social dominance effects on development of the reproduction function in male mice. Sperm quality, relative testis and epididymis weights were evaluated in male mice of PT and CBA/Lac inbred strains at 70 day of age after pairing throughout the 32 day period. The effect of social dominance on sperm quality was observed only in males of the CBA/Lac strain. The dominant males had higher sperm count than subordinates or control. The result revealed also higher percent of abnormal sperm among dominant or subordinate males compared with control. It was suggested that the effects of social competition on spermatogenesis depend on a genotype and social status.

[Regional peculiarities in semen quality and serum hormonal concentrations of citizens from Eastern Siberia]

The objective of the present study was to evaluate sperm quality and reproductive hormonal level in an unselected population of men who were permanent residents of the Yakutsk city and compare the semen and hormonal parameters with the World Health Organization (WHO, 2001) recommended normal values and the results from other countries. A total of 145 men (mean age 24,1 years) agreed to be included in the study. All the volunteers completed a questionnaire, received a general and reproductive health examination by an andrologist, gave semen and blood samples. We found that the means were 34,69 - 106 spermatozoa/mL for sperm concentration and 39,6% for total motile spermatozoa. Among all volunteers studied 4,3% had azoospermia, 27,0% reported oligozoospermia, 68,1% - asthenozoospermia. There are no differences between Yakut and Slavs in anthropometric, hormonal or sperm measures, but height and ejaculate volume were higher in Slavs than Yakut men. The data obtained indicated high frequency of suboptimal quality of sperm in males of both nations from this Siberian region in comparison with other Russian regions or European countries.

[The age-related aspects of changes in hormones' level in hypophysis-thyroid and hypophysis-gonads systems in residents of Arkhangelsk]

The male permanent residents of Arkhangelsk were examined during the period of daylight hours minimal duration for the purpose to determine the age-related changes in hormones' level. In the age group of 36-45 years the level recession of progesterone, cortisol and testosterone free fractions against the background of broadening towards higher standard limit of fluctuations of steroid-binding beta-globulin level was demonstrated. In the age group of 46-60 years the rise of cortisol level and tendency to level recession of free thyroxin under thyrotrophic hormone level increase was registered. The hypophysial regulation consisted in lutropin and prolactin level lowering at the age of 36-45 years and in rise of thyrotrophic hormone level at the age of 46-60 years.

Genetic variability of spermatozoon production and morphology in laboratory mice

Strain-specific differences in the production of spermatozoa and incidence of atypical spermatogenesis were studied in males of 7 inbred strains: BALB/cLac, PT, CBA/Lac, DD, A/He, C57Bl/6J, and YT. The results attest to significant genetic variability of the counts of epididymal spermatozoa (differing by more than 1.5-2 times) and incidence of abnormal spermatozoon heads (differing by more than 4 times). However, the strain-specific variability of both signs was not coordinated. The selected set of inbred mouse strains can become a prospective genetic model for studies of physiological and hereditary nature of spermatogenesis variability.

[Phenogenetic analysis of testicular responsiveness to chorionic gonadotropin in inbred mouse strains]

Genetic differences in the testicular hormonal responsiveness to in vivo administration of chorionic gonadotropin (CG) between adult male mice of eight inbred strains (A/Sn, CBA/Lac, CC57Br, C57Bl/6J, DBA/2J, GR, PT, and YT) were determined. In addition, the genetic variation of the body and testis weights was estimated as related to the responsiveness to stimulation of steroidogenesis with CG. Adult males were subcutaneously injected with 10 IU of CG or physiological saline 120 min before decapitation. It was found that the baseline testosterone level in the blood serum and its content in the testes only slightly varied in males of the strains studied. Administration of CG increased these parameters by a factor of 3-45, depending on the strain. The results of the study indicate genetic differences in the testicular reactivity to CG. In addition, it has been found that the response to administration of CG, as compared to the baseline levels, provides the most reliable information on the genetic characteristics of the hormonal potential of the testes. The given set of inbred mouse strains may be a promising genetic model for studying the physiological and hereditary variations of testicular steroidogenesis.

Hormonal reaction of the testes to chorionic gonadotropin in CBA/Lac and PT mice: effects of the dose and time after treatment

Testosterone concentrations in the blood of CBA/Lac and PT mice and its content in the testes under normal conditions and during stimulation with chorionic gonadotropin were measured by enzyme immunoassay. Genetic differences in reactivity of the testes to chorionic gonadotropin were revealed: PT mice were characterized by more pronounced hormonal reaction compared to CBA/Lac mice. An optimal dose of chorionic gonadotropin (10 U) and time interval (120 min) for evaluation of potentialities of testicular hormonal function were determined.

[Interstrain differences in testicular responses to hCG: effects of a female exposition]

It is known that among many animal species, including laboratory mice, a short-time exposition to a female causes activation of the pituitary-testicular axis in males, which then rapidly decreases. Effects of a prolonged female exposition on the testicular testosterone output in response to hCG injections were investigated in adult males of two inbred mice strains CBA/Lac and PT. The males of both genotypes kept with females for 5 days were injected subcutaneously with 10 IU of hCG 120 minutes before decapitation. Males of the same genotype and similar age keeping alone were served as control. The serum testosterone concentration and its testicular content were measured with immune-enzyme assay. It has been shown that the hCG increased the testosterone concentration and its testicular content in control males of both strains, but the testosterone output was expressed more significantly in PT males in comparison with CBA/Lac. The prolonged exposition of a female itself did not influence the testosterone output in males of both strains. However, it increased significantly the testicular response to hCG in PT strain. The data obtained suggest that a long-term exposition of a female could reinforce the testicular reactivity to hCG in genotype-dependent manner.

[Genotype-related changes in the reproductive function under social hierarchy in laboratory male mice]

The study was designed to investigate genetic differences in reproductive consequences of social hierarchy using inbred mice strains BALB/cLac, PT and CBA/Lac. Two adult males of different genotypes were housed together for 5 days. Hierarchical status of both partners was determined by asymmetry in agonistic behavior. The number of epididymal sperm and a proportion of abnormal sperm, weights of reproductive organs, serum concentration and testicular content of testosterone, and the testosterone response to introduction of a receptive female were determined. The testosterone measures were significantly decreased in the PT strain, the epididymal sperm number was significantly decreased in the BALB/cLac strain and a proportion of abnormal sperm heads was significantly increase in the CBA/Lac (in both dominants and subordinates) as compared to control mice. The testicular testosterone response to a receptive female and precopulatory behavior was unchanged in dominants and suppressed in subordinates of the BALB/cLac strain. The results indicate that in laboratory mice the pattern of reproductive response to social hierarchy is determined by genetic background.

[Interlinear differences in generative function formation in pubescence of male mice]

The formation of generative function in pubescence is studied in males of three inbred mice lines BALB/cLac, CBA/Lac, and PT. From days 35 through 60 of life every 5 days the amount of sperm cells and the quantity of abnormal heads of spermatozoa in males are calculated in both epididymises and the morphometry of the testicles, epididymises, and seminal vesicles is carried out. Interlinear deviations in the pubertal dynamics of the parameters of spermatogenesis and the morphometric indexes are determined, indicating a weak spermatogenesis process in males of CBA/Lac in comparison with males from the other lines. Males from the line CBA/Lac are characterized by a low amount ofepididymal spermatozoa combined with low frequency of abnormal spermatozoon heads; these traits can be considered as a compensatory process that increases fertility, By the end of the period, i.e., on days 55-60 of life, the males of all three inbred mice lines have not reached the definitive level in the number ofepididymal spermatozoa; the weight of the testicles, epididymise, and seminal vesicles; and body weight. Thus, in laboratory mice, the beginning of reproductive activity is not connected with these reproductive indexes reaching the definitive level. The results of the study show that in adult mature males of laboratory mice the interlinear deviations in generative function emerge in the pubertal period and persist thereafter.

[Testicular function in mice of inbred strains BALB/cLac, PT, and CBA/Lac]

The main features of male fertility: sperm production and abnormalities, testosterone serum concentration and its testicular content after hCG injections, weights of the testes and cauda epididymes, were studied in adult males of three inbred mice strains BALB/cLac, PT, and CBA/Lac. The CBA/Lac males were characterized by lower value of the epididymal sperm number, as well as lower weights of reproductive organs in comparison with males of other inbred strains. The lower number of sperm is accompanied in the CBA/Lac males with lower proportion of morphologically abnormal spermatozoa as compared to other strains that could compensate its decreased count and improve fertility. The baseline testosterone concentration and its testicular content did not differ among the three strains but the testosterone response to injection of 10 IU of hCG was weaker in the CBA/Lac males than in the others. The results indicate significant interstrain differences in testicular traits implicated in male fertility which may be correlated and compensate to each other.

[Interstrain differences in social and time patterns of agonistic behavior in male laboratory mice]

The aim of present study was to reveal the genetic effects on social dominance and patterns of agonistic behaviors in social partners. The study was carried out in adult male mice of three inbred strains BALB/cLac, CBA/Lac and PT using an ethological model of social hierarchy, which is characterised by the minimal size and genetic heterogeneity (two males of different genotypes). We used a neutral territory as the experimental territorial condition for the establishment of social hierarchy. Rank asymmetry in aggressive and defensive behaviors was quickly formed during the first day after the production of the social. Significant interstrain differences in time patterns ofagonistic behavior in dominants and subordinates as well as in the level of social dominance determined as a proportion of dominant animals in the strain were observed. In was shown that, in laboratory mice, the genotype could markedly influence social dominance and the patterns of agonistic behavior in social partners.