Immunolocalization of PTHrP in prepubertal and pubertal testis of European bison

The present study deals with immunohistochemical localization of PTHrP in prepubertal and pubertal testis of European bison. PTHrP immunoreactivity was observed in germinal cells in the testis of both prepubertal and pubertal animals. In calves, PTHrP was found in germinal cells, in seminiferous tubules lacking the lumen. The reaction was strong and regularly distributed within the cytoplasm. In adult animals, the reaction showed differentiation in spermatogenic cells. Some cells were strongly and diffusely stained, others exhibited weaker reaction of granular pattern. Sertoli cells and Leydig cells were PTHrP-negative in calves and adult animals.     

Immunolocalization of androgen receptors in testicular cells during postnatal development of the bank vole (Clethrionomys glareolus, S.)

Determination of the cellular distribution of the androgen receptors within the testis is of great importance for an understanding of their essential role in mediating of androgen action in the male gonad. In bank voles, which are seasonally breeding rodents, photoperiod is one of the most important factors inducing profound changes in the morphology and hormonal activity of the testes. Immunolocalization of androgen receptors was found in all somatic cells such as Sertoli cells, Leydig cells, and peritubular-myoid cells, however, distribution of the androgen receptors in various cell types depended on age of animals. Intensity of immunoreactivity was noticed as age and photoperiod-dependent. Males reared under different light regimes showed a significant correlation between the length of light and sexual maturation. Therefore, morphology of the testis from young and adult bank voles was also presented.     

Effects of tri-iodothyronine on testicular interstitial cells and androgen secretory capacity of the prepubertal Rat

The main objective of the study was to investigate the effects of hyperthyroidism on the rat testis interstitium during prepuberty, which is not well understood at present. Male Sprague Dawley rats were injected subcutaneously daily with saline (controls) or tri-iodothyronine (T(3), 50 microg/kg body weight; hyperthyroids) from postnatal Day 1. Rats were killed at Days 5, 7, 9, 12, 16, and 21. One testis of each rat was used to determine LH-stimulated (100 ng/ml) testicular androgen secretory capacity in vitro. The other testis was used either for morphometric studies (n = 5) or for immunolocalization of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) to identify steroidogenic cells (n = 3) and 11 beta-hydroxysteroid dehydrogenase 1 (11 beta-HSD1) to differentially identify adult Leydig cells. Daily T(3) injections resulted in significant reductions in body and testis weights. Morphometric analysis revealed that lower testis weights in rats treated with T(3) were mainly the result of reductions of total volume of seminiferous cords/tubules. The number of interstitial mesenchymal cells (MCs) was lower (P < 0.05) in T(3) rats compared with age-matched controls. The number of fetal Leydig cells (FLCs) was not different between the two groups; however, FLC hypotrophy was detected in T(3) rats at Day 16 in contrast to Day 21 in control rats. In both groups, morphologically identifiable adult Leydig cells (ALCs) were observed at Day 12 and thereafter; however, the ALC number per testis in T(3) rats was twice as much as those of controls. Positive immunolabeling for 3beta-HSD was first detected in MC/progenitor cells on Day 9 in rats in the T(3) group (cells were still spindle-shaped) and on Day 12 in rats in the control group. Testicular testosterone production in vitro was lower (P < 0.05) in T(3) rats compared with controls at each age tested and further reductions (<0.05) were observed in T(3) rats at Days 16 and 21. Testicular androstenedione production was also lower (P < 0.05) in T(3) rats at Days 5 and 7, but increased (P < 0.05) thereafter, than in control rats. These findings support that there are more newly formed ALCs in T(3) testes than in those of controls. Moreover, these results demonstrate that hyperthyroidism stimulates premature hypotrophy of FLCs and early differentiation of increased numbers of MCs to ALCs in the prepubertal rat testis, further supporting the view that thyroid hormone has a regulatory role in initiating MC differentiation into ALCs in the prepubertal rat testis.     

Immunohistochemical localization of androgen receptors in testicular cells of mice with mosaic mutation

Mice with mosaic mutation could be one of the models of human Menkes disease, which is associated with abnormal cooper metabolism. The aim of the present study was to localize androgen receptors (ARs) in the testes by means of immunohistochemistry. AR expression was observed in the nuclei of all somatic cells such as Leydig cells, Sertoli cells, and peritubular cells in sections from testes of control and mosaic mutant males. In the latter, very strong immunoreactivity for AR as well as higher levels of steroid hormones in homogenates were noticed in comparison to control mice. No positive immunoreaction for ARs was seen in control sections incubated without the primary antibody.     

Immunolocalization of estrogen and androgen receptors and steroid concentrations in the stallion epididymis

The presence of steroids and their receptors throughout development, specifically androgen receptor (AR), estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta), in the epididymis of a high estrogen producing species like the stallion has not been determined. Epididymal and testicular samples were collected for analysis of testosterone and estradiol-17beta (E(2)) concentrations and for immunolocalization of AR, ERalpha and ERbeta. The concentration of testosterone in the testis and epididymis were not different among age groups (P>0.05). AR was localized in the principal cells of the caput, corpus and cauda in all four age groups. This lack of change in testosterone concentration and receptor localization suggests that testosterone is important for both development and maintenance of epididymal function. There was an age-related increase in E(2) concentrations in all regions of the epididymis (P<0.05), suggesting that E(2) is also important for adult function. ERbeta was localized in the principal cells of the caput, corpus and cauda in all four age groups, but the localization of ERalpha was regional and age dependent. In peri-pubertal animals, ERalpha immunostaining was most prominent and estradiol was similarly present in all three epididymal regions; this suggests that estradiol also plays a key role in the maturation of the stallion epididymis during the pubertal transition when sperm first arrive in the epididymis. In conclusion, these results suggest that the stallion epididymis is regulated by both androgens and estrogens throughout development and that estradiol is more important to epididymal function in the stallion than previously believed.     

Role of thyroid on testicular lipids in prepubertal, pubertal and adult rats. I. Hyperthyroidism

The influence of thyroxine-induced hyperthyroidism on testicular neutral and phospholipids was studied in prepubertal, pubertal and adult rats. Thyroxine treatment (25 micrograms/100 g body weight) for 1 month decreased testicular total lipids, total glyceride glycerols, total cholesterol and total phospholipids. Different classes of glyceride glycerol, cholesterol and phospholipid were also diminished due to thyroxine treatment. All classes of lipids returned to the euthyroid level after the withdrawal of thyroxine treatment. The data obtained in the present study suggest that thyroid hormones have a definite influence on testicular lipid metabolism in rats.     

Nycthemeral plasma and testicular androgen contents in guinea pigs at puberty]

A study based upon transversal sampling involving 13 series of 7 animals each does not show a significant circadian rhythm of testosterone and delta4 androstenedione concentrations in the plasma and testis of the guinea-pig at the age of puberty.     

Streptozotocin-diabetes impairs prolactin binding to Leydig cells in prepubertal and pubertal rats.

Prolactin (PRL) binding to Leydig cells in prepubertal and pubertal streptozotocin (STZ)-diabetic and insulin-treated rats was studied. Prepubertal (30-day-old) and pubertal (50-day-old) rats were made diabetic by single injection of STZ (120 and 100 mg/kg b.wt, respectively). After 3 days of STZ administration, a group of rats was given insulin injections subcutaneously (3 U/100 g b.wt/day in 2 equally divided doses). Animals of prepubertal and pubertal groups were killed on postnatal days 51 and 71, respectively. Age-dependent increase in serum testosterone, PRL levels and PRL receptors on Leydig cells were prevented by STZ-diabetes. Insulin administration partly or completely prevented these changes. These results suggest that steroidogenic defects in Leydig cells of prepubertal and pubertal diabetic rats may be associated with decrease in serum PRL levels and its receptors on Leydig cells. Insulin probably has a role in the maintenance of PRL receptor numbers on Leydig cells during pubertal maturation.     

Luteinizing hormone-releasing hormone in prepubertal and pubertal girls.

Estimations of immunoreactive LH-RH and LH in pooled sera of girls, adult women and postmenopausal women have been carried out. The girls were divided into three groups: I--girls aged 2--4 years, II--girls aged 5--8 years and III--girls 9--12 years of age. The estimated concentrations of LH-RH in particular groups were as following: in group I--1.2 +/- 0.2 pg/ml, in group II--2.2 +/- 0.4 pg/ml, in group III 31.0 +/- 4.4 pg/ml, in adult women 6.3 +/- 1.8 pg/ml. and in postmenopausal women 16.6 +/- 2.4 pg/ml. The concentrations of LH in the same groups were 4.3 +/- 0.7; 4.5 +/- 0.8; 11.0 +/- 1.4, 23.3 +/- 2.4; and 120.0 +/- 14.7 mIU/ml, respectively. The authors suggest that the sexual maturation of girls is initiated by the enhanced hypothalamic activity, reflected in higher concentrations of immunoreactive LH-RH in peripheral serum.     

Postnatal changes in testicular development and androgen receptors immunolocalization in D'Man ram lambs

The purpose of this study was to characterize testicular development in D'Man ram lambs, focusing primarily on androgen receptors (ARs) immunolocalization in the adenohypophysis and testis that is not still known in the D'Man ram lamb. Lambs (n = 12) were divided into four groups (three lambs per group). Adenohypophysis and testis were fixed and paraffin embedded; cross-section (3 μm) were stained and evaluated with immunohistochemistry. Testis weight increased at a greater rate between two and five months after birth, which was associated with remarkable changes in testicular histology, including significant increases in the diameter of seminiferous tubules. Spermatogenesis started between three and five months after birth; lumen and elongated spermatids were observed for the first time in three and four months-old animals respectively. ARs detected with immunohistochemistry were located in the nuclei and cytoplasm of adenohypophysis cells, and only in nuclei of testis cells (Leydig, Sertoli, peritubular myoid and germ cells).     

Gender differentiations of cognitive-motor functioning in prepubertal and pubertal children

The aim of this study was to determine cognitive and motor status factors in female and male children aged 10-14, as well as developmental and/or integration functions according to gender. The study included 162 girls and 134 boys aged 10-14, divided into four groups: 84 girls aged 10-12 (mean age 11.26, SD 0.68), 84 boys aged 10-12 (mean age 11.41, SD 0.50), 78 girls aged 13-14 (mean age 13.52, SD 0.63) and 50 boys aged 13-14 (mean age 13.21, SD 0.53). The significance of quantitative differences between boys and girls in the overall system of variables was defined based on the results of canonic discriminant analysis of variance, and within each variable based on the results on univariate analysis of variance (ANOVA). In the younger age group (10-12 years), girls were superior to boys in a test assessing flexibility (Seated straddle stretch), whereas, compared to girls, boys had greater strength of the trunk (Crossed-arm sit-ups), greater explosive strength ofjump and sprint type (Standing broad jump and 20 m dash), and coordination (Obstacle course backwards and Steps laterally). In the older age group (13-14 years) differences in flexibility were even more prominent in favor of girls, whereas the differences in explosive strength increased in favor of boys, especially of the throwing type with better agility (Steps laterally), balance (Board balance) and greater static strength of arms and shoulders (Bent-arm hang). In order to determine qualitative differences between pubertal and prepubertal girls and boys, the matrix of variable inter-correlations was factorized by the procedure of principal components procedure, that were then transformed to promax solution. The results showed that cognitive functioning had a significant role in the motor efficacy of girls and boys aged 10 to 14. In the age group of 10-12 years, in females, cognitive functioning is related to the motor system which integrates the regulation of muscle tone with agility/coordination, whereas in males there is a relation between cognitive abilities and the regulator of speed of upper extremities movement frequency. In the age group of 13-14 years, in females, cognitive functioning is involved in forming the factors for regulation of coordination and the intensity of energy mobilization in lower extremities, and to some degree, in the factor for regulation of intensity of energy mobilization in upper extremities and strength of the trunk, whereas in males the integration of synergetic regulation of movement in terms of balance and agility in terms of speed of direction change is carried out with significant involvement of cognitive abilities.     

Immunolocalization of androgen and vitamin D receptors in the epididymis of mature ram (Ovis aries)

This study illustrated the immunohistochemical distribution of androgen and vitamin D receptors of epididymis in 20 sexually mature ram (Rahmani breed) with average age ranged from (2^_4) years and average weight ranged from (50^_65kg). Androgen receptor was localized in the cytoplasm of both ciliated and non ciliated cells of efferent ductules, besides the principal cells via the entire epididymal duct. The principal cells of both corpus and proximal cauda epididymis showed the highest immunoreactivity to androgen receptors. Furthermore, vitamin D receptor was localized in the cytoplasm of all epithelium of the efferent ductules besides principal cells of all epididymal regions, however the immunoreaction was significantly higher in the efferent ductules, distal caput and distal cauda epididymis. In conclusion, these results suggest that the function of ram epididymis is regulated by both androgen and Vitamin D.     

The effect of a sertoli cell-selective knockout of the androgen receptor on testicular gene expression in prepubertal mice

To unravel the molecular mechanisms mediating the effects of androgens on spermatogenesis, testicular gene expression was compared in mice with Sertoli cell-selective androgen receptor knockout (SCARKO) and littermate controls on postnatal d 10. Microarray analysis identified 692 genes with significant differences in expression. Of these, 28 appeared to be down-regulated and 12 up-regulated at least 2-fold in SCARKOs compared with controls. For nine of the more than 2-fold down-regulated genes, androgen regulation was confirmed by treatment of wild-type mice with an antiandrogen (flutamide). Some of them were previously described to be androgen regulated or essential for spermatogenesis. Serine-type protease inhibitors were markedly overrepresented in this down-regulated subgroup. A time study (d 8-20), followed by cluster analysis, allowed identification of distinct expression patterns of differentially expressed genes. Three genes with a pattern closely resembling that of Pem, a prototypical androgen-regulated gene expressed in Sertoli cells, were selected for confirmation by quantitative RT-PCR and additional analysis. The data confirm that the SCARKO model allows identification of novel androgen-regulated genes in the testis. Moreover, they suggest that protease inhibitors and other proteins related to tubular restructuring and cell junction dynamics may be controlled in part by androgens.     

Human sympathoadrenal system and adrenal cortex in prepubertal and pubertal periods

A complex study of the functional state of the sympathoadrenal system and adrenal cortex in 10-15-year-old children of both sexes was carried out using the indices of daily excretion of adrenaline, noradrenaline, 17-ketosteroids, and 17-hydroxycorticosteroids. A synchronism in the functional activity of the mediator component of the sympathoadrenal system as well as of the androgenic and glucocorticoid functions of the adrenal cortex was observed with age and during pubertal development of children. At the same time, heterochronic maturation was observed in the sex groups: in girls at the age of 10 and 12 years and in boys at the age of 14-15 years. The changes of different direction and intensity in the excretion of the studied hormones and hormonal metabolites were observed in the sex and age groups. A sharp increase in the daily excretion of glucocorticoid metabolites accompanied by a considerable decrease in the age index of noradrenaline secretion was observed in 14- and 15-year-old boys from beginning to end of school year; in addition, an increase in the daily excretion of sex hormones was observed at the age of 15 years. In girls, these indices varied within the age range, which points to a more sophisticated neuroendocrine control of physiological functions in girls during puberty.     

Human sympathoadrenal system and adrenal cortex in prepubertal and pubertal periods

A complex study of the functional state of the sympathoadrenal system and adrenal cortex in 10–15-year-old children of both sexes was carried out using the indices of daily excretion of adrenaline, noradrenaline, 17-ketosteroids, and 17-hydroxycorticosteroids. A synchronism in the functional activity of the mediator component of the sympathoadrenal system as well as of the androgenic and glucocorticoid functions of the adrenal cortex was observed with age and during pubertal development of children. At the same time, heterochronic maturation was observed in the sex groups: in girls at the age of 10 and 12 years and in boys at the age of 14–15 years. The changes of different direction and intensity in the excretion of the studied hormones and hormonal metabolites were observed in the sex and age groups. A sharp increase in the daily excretion of glucocorticoid metabolites accompanied by a considerable decrease in the age index of noradrenaline secretion was observed in 14-and 15-year-old boys from beginning to end of school year; in addition, an increase in the daily excretion of sex hormones was observed at the age of 15 years. In girls, these indices varied within the age range, which points to a more sophisticated neuroendocrine control of physiological functions in girls during puberty.     

Variations in testicular androgen receptors and histology of the lamb testis from birth to puberty

Changes in testicular androgen receptor numbers were studied in lambs from 25 to 100 days of age. During this period, cytoplasmic receptors increased from 5 to 80 pmol/testis and nuclear receptors from 1 to 12 pmol/testis, while the total volume of Leydig cells increased 7-fold. The total number of Sertoli cells doubled between 25 and 40 days of age. From 40 days onward their number remained constant while their cellular and nuclear sizes increased by a factor of 3 and 1.5 respectively. Cytoplasmic receptor concentration was positively correlated with the number of Sertoli cells per section of seminiferous tubule, and negatively correlated with the number of germinal cells per cross section. One explanation for these results could be that Sertoli cells are the main androgen target cells in lamb seminiferous tubules.     

Direct measurement of androgen receptors in cultured sertoli cells

Cytoplasmic and nuclear forms of macromolecules with the properties of androgen receptors have been demonstrated by direct labeling techniques in cultured Sertoli cells. The cytoplasmic form was excluded from Sephadex G-200 and could be distinguished from androgen binding protein (ABP) on the basis of size, heat stability, relative electrophoretic mobility, and binding complex dissociation rate. When cultured Sertoli cells were incubated with ³H-testosterone, a time- and temperature-dependent accumulation of label into the nuclear fraction was observed, 46% of which crystallized as authentic testosterone. Specific binding was saturable with an apparent association constant of 0.4nM^?1. Approximately 30% of the nuclear bound hormone was extracted within 1 h by 0.4M KCl and 34% of this was associated with macromolecular species as measured by gel filtration. Unlabeled androgens and to some degree progestogens competed with ³H-testosterone for binding sites. These data constitute direct evidence that Sertoli cells contain androgen receptors.