Carbamazepine-exposure during gestation and lactation affects pubertal onset and spermatic parameters in male pubertal offspring

Carbamazepine (CBZ) is an anti-epileptic drug that acts on Leydig cells, affecting steroidogenesis and causes fetal malformation. The aim of this study was to investigate the effects of CBZ on male sexual maturation and other male parameters. Rat dams were treated with CBZ during pregnancy and breastfeeding. The anogenital distance (AGD) and the anogenital index (AGI) were obtained. Testicular descent and preputial separation were also evaluated. The offspring was euthanized at PND 41 and 63. The accessory glands were weighed and the testes were collected for histopathological, morphometric and sterological analyses. The numerical density of Leydig cells and hormone dosage were obtained. CBZ caused an increase of AGI and a delay of testicular descent and of preputial separation. CBZ also caused a decrease of testosterone level and of sperm count and an increase of abnormal sperm. These results indicate that CBZ delays puberty onset and affects steroidogenesis and sperm quality.     

米非司酮与皮质醇合用对大鼠睾丸间质细胞分泌睾酮的影响

为研究米非司酮和皮质醇对大鼠睾丸间质细胞(Leydig Cells)的睾酮基础分泌及促性腺激素刺激睾酮分泌的影响,将雄性大鼠处死,取睾丸间质细胞进行体外培养,用放射免疫分析方法测定睾酮含量。实验结果显示米非司酮抑制睾酮的基础分泌,而皮质醇对其无影响;两药单独使用时,均抑制促性腺激素刺激的睾酮分泌,合用有协同作用。本研究表明米非司酮和皮质醇均能影响睾丸的甾体激素的合成。     

Sesquiterpene lactone helenalin suppresses Leydig and adrenocortical cell steroidogenesis by inhibiting expression of the steroidogenic acute regulatory protein

Helenalin is a potent anti-inflammatory and anti-neoplastic agent isolated from several plant species of the Asteracea family. Here, we have investigated the effects of helenalin on steroidogenesis activated by adrenocorticotropic hormone (ACTH) and human chorionic gonadotropin (hCG) in primary cultures of rat adrenocortical and Leydig cells. Our findings demonstrate that helenalin inhibits both ACTH- and hCG-activated steroidogenesis in these cells. This effect was already evident after 2–3 h treatment with helenalin. In contrast, steroidogenesis from 22R-OHC, a cell-permeable form of cholesterol, was not inhibited by helenalin, suggesting that the expression of the steroidogenic acute regulartory (StAR) protein might be inhibited by this compound. Indeed, helenalin attenuated StAR protein expression activated by ACTH and hCG in adrenocortical and Leydig cells as assessed by PAGE/Western analyses. This inhibitory action of helenalin on steroidogenic cell functions indicates novel mechanisms of action of this compound which may be of potential therapeutic interest. However, it also poses safety concerns relating to possible negative side-effects on anabolism and systemic stress.     

Reversible Changes in the Antifertility Induced by Aegle marmelos in Male Albino Rats

To study the effects of Aegle marmelos on the testicular reproductive system, a 50% ethanolic extract of Aegle marmelos leaves (AMLEt) was fed orally to male albino rats at the dose levels of 200 and 300?mg/kg body wt./day for 60 days. Recovery was assessed for an additional 120 days. Oral administration of AMLEt did not cause body weight loss. The motility and sperm concentration were significantly reduced along with complete inhibition of fertility at a dose of 300?mg/kg. The level of serum testosterone also declined and spermatogenesis was impaired. The number of normal tubules and the height of epithelial cells of the caput and cauda were reduced significantly. The cross sectional surface area of Sertoli cells and mature Leydig cells was reduced along with a dose dependent reduction of preleptotene and pachytene spermatocytes. Thus the antifertility effects of Aegle marmelos seemed to be mediated by disturbances in structure and function in testicular somatic cells including Leydig and Sertoli cells resulting in an alteration in physio-morphological events of spermatogenesis. However, complete recovery was observed after a 120 day withdrawal.     

THYROID HORMONES: THEIR ROLE IN TESTICULAR STEROIDOGENESIS

Thyroid hormones are important for growth and development of many tissues. Altered thyroid hormone status causes testicular abnormalities. For instance, juvenile hypothyroidism/neonatal transient hypothyroidism induces macroorchidism, increases testicular cell number (Sertoli, Leydig, and germ cells) and daily sperm production. Triiodothyronine (T3) receptors have been identified in sperm, developing germ cells, Sertoli, Leydig, and peritubular cells. T3 stimulates Sertoli cell lactate secretion as well as mRNA expression of inhibin- &#102, androgen receptor, IGF-I, and IGFBP-4. It also inhibits Sertoli cell mRNA expression of Müllerian inhibiting substance (MIS), aromatase, estradiol receptor, and androgen binding protein (ABP) and ABP secretion. T3 directly increases Leydig cell LH receptor numbers and mRNA levels of steroidogenic enzymes and steroidogenic acute regulatory protein. It stimulates basal and LH-induced secretion of progesterone, testosterone, and estradiol by Leydig cells. Steroidogenic factor-1 acts as a mediator for T3-induced Leydig cell steroidogenesis. Although the role of T3 on sperm, germ, and peritubular cells has not yet been completely studied, it is clear that T3 directly regulates Sertoli and Leydig cell functions. Further studies are required to elucidate the direct effect of T3 on sperm, germ, and peritubular cells.     

EFFECTS OF TREMELLA MESENTERICA ON STEROIDOGENESIS IN MA-10 MOUSE LEYDIG TUMOR CELLS

Tremella mesenterica (TM), a yellow jelly mushroom, has been traditionally used as food and crude medicine to improve several kinds of symptoms in Chinese society for a long time. Recent studies have illustrated that the fractions of fruiting bodies of TM exhibit a significant hypoglycemic activity in diabetic mouse models, which usually suffer from sexual dysfunction. In a previous study, we showed that TM reduced plasma testosterone production in normal rats without any positive effect in diabetic rats. It evolved a question of TM directly regulating Leydig cell steroidogenesis. In this study, MA-10 mouse Leydig tumor cells were treated with vehicle, different dosages of TM with or without human chorionic gonadotropin (hCG 50 ng/ml) to clarify the effects. Results showed that TM at different dosages (0.01–10 mg/ml) did not have any effect on MA-10 cell steroidogenesis (p > 0.05). In the presence of hCG, there was an inhibitory trend that TA suppressed MA-10 cell progesterone production at 3 hr treatment with a statistically significant difference by the 10 mg/ml TM (p < 0.05). In time course effect, TM alone did not have any effect on MA-10 cell steroidogenesis from at 1, 2, 3, 6 and 12 hr (p > 0.05). However, TM did reduce hCG-treated MA-10 cell progesterone production at 1, 2 and 3 hr (p < 0.05), respectively. To determine whether TM would have adverse effects on MA-10 cell steroidogenesis in the presence of hCG, MTT assay and recovery studies were conducted. MTT assay indicated that TM had no effect on surviving cells. In addition, with the removal of TM, and then the addition of hCG (2 and 4 hr), progesterone levels were restored within 4 hr. Taken together, present studies suggested that TM suppressed hCG-treated steroidogenesis in MA-10 cells without any toxicity effect.     

Toxicological effects of acrylamide on rat testicular gene expression profile

Toxicological effects of acrylamide on differential gene expression profile of rat testis were evaluated. Acrylamide induced morphological sperm defects, and decreased sperm concentration in cauda epididymis. Serum testosterone level and Leydig cell viability were also decreased dose-dependently, which resulted in decreased spermatogenesis. Acrylamide-induced histopathological lesions, such as formation of multinucleated giant cells and vacuolation, and numerous apoptotic cells were observed in seminiferous tubules. cDNA microarray analysis revealed that genes related to testicular-functions, apoptosis, cellular redox, cell growth, cell cycle, and nucleic acid-binding were up/down-regulated in testes isolated from acrylamide-treated group (60 mg/kg/day). Acrylamide toxicity appears to increase Leydig cell death and perturb gene expression levels, contributing to sperm defects and various abnormal histopathological lesions including apoptosis in rat testis.     

Alterations in endocrine responses in male Sprague-Dawley rats following oral administration of methyl tert-butyl ether.

Methyl tert-butyl ether (MTBE) is an oxygenated fuel additive used to decrease carbon monoxide emissions during combustion. MTBE is a nongenotoxic chemical that induces Leydig cell tumors (LCT) in male rats. The mechanism of MTBE-induced LCT is not known; however, LCT induced by other nongenotoxic chemicals have been associated with the disruption of the hypothalamus-pituitary-testicular (HPT) axis. The objective of this study was to determine whether MTBE functions as an endocrine-active compound by affecting levels of specific hormones involved in the maintenance of the HPT axis. Nine-week-old male Sprague-Dawley rats were administered MTBE by gavage at 0, 250, 500, 1000, or 1500 mg MTBE/kg/day for 15 or 28 consecutive days and sacrificed 1 h following the last dose. Relative testis weights were increased only in high-dose animals treated for 28 days, and no testicular lesions were observed at any dose level. Adrenal gland, liver, and kidney weights were also increased. Histologic changes included protein droplet nephropathy of the kidney and centrilobular hypertrophy of the liver. Interstitial fluid and serum testosterone levels as well as serum prolactin levels were decreased only in animals treated with 1500 mg MTBE/kg/day for 15 days. At 28 days, serum triiodothyronine (T3) was significantly decreased at 1000 and 1500 mg MTBE/kg/day compared to control animals, and a decrease in serum luteinizing hormone and dihydrotestosterone was observed at 1500 mg MTBE/kg/day. These results indicate that MTBE causes mild perturbations in T3 and prolactin; however, the changes in testosterone and LH levels did not fit the pattern caused by known Leydig cell tumorigens.     

Isolation method of Leydig cells from mature male Djungarian hamsters (Phodopus sungorus) and their steroidogenic activity in vitro

For studies addressing the functions of Leydig cells, isolated cells are often better suited than intact animals. Here, the isolation procedure of Leydig cells from adult male Djungarian hamsters (Phodopus sungorus) is described. Cells were isolated using a procedure involving enzymatic dissociation and Percoll-gradient centrifugation. For each experiment, approximately 4.4 x 10(6) Leydig cells from six animals were obtained. The cells showed high steroidogenic responsiveness to physiological (ovine luteinizing hormone (oLH) and human chorionic gonadotropin (hCG)) and nonphysiological (forskolin) stimuli in vitro. Approximately 98% of cells were viable as assessed by trypan blue exclusion, and the purity varied from 80 to 95% as tested by 3 beta-hydroxysteroid dehydrogenase activity. Leydig cells were also identified by a bright yellow halo under phase-contrast microscopy. They contained numerous lipid droplets and showed round nuclei and prominent nucleoli. The cells responded to oLH, hCG and forskolin with an increased testosterone production in a dose-dependent manner. Dose-response curves in these studies suggest that Leydig cells of Djungarian hamsters undergo desensitization, probably due to down regulation of their LH/CG receptors.     

小鼠Leydig肿瘤细胞膜受体LHR减量调节中受体基因转录变化及其机制

膜受体的减量调节是受体在转导跨膜信号的同时，其数目呈进行性下降的一种细胞生物学行为。本文运用ＲＴＣＲ、放免分析及“ｒｕｎｏｎ”等技术研究小鼠Ｌｅｙｄｉｇ 细胞株ＬＨ 受体（ＬＨＲ） 减量调节过程中ＬＨＲ ｍＲＮＡ 水平变化及其调控机制。结果揭示，在ｈＣＧ作用后ＬＨＲ 减量调节的过程中，ＬＨＲｍＲＮＡ 水平发生了“升高降低”的变化，这种变化是ＬＨＲ基因转录活性的变化决定的，与ＬＨＲｍＲＮＡ 的降解无关，ｃＡＭＰ 以“正相关”的方式调控着ＬＨＲ基因的转录速率。