Expression of Hsp70-2 in unilateral cryptorchid testis of rhesus monkey during germ cell apoptosis

We investigated the possible role of Hsp70-2 in germ cell apoptosis induced by heat stress in monkey unilateral cryptorchid testis. The study focused on in situ analysis of the testicular cell DNA fragmentation and on the possible relationship between Hsp70-2 expression and germ cell apoptosis. The TUNEL result showed that most of the germ cells were labeled in the cryptorchid testis on d 5 after induction of cryptorchidism; that with most of the apoptotic germ cells depleted, only a few germ cells were labeled on d 10; and that almost no apoptotic signal was observed in the cryptorchid testis on d 15 and thereafter. This indicates that the increasing germ cell degeneration in cryptorchid testis may take the form of apoptosis. Using in situ hybridization, immunohistochemistry, and Northern blot, we examined the changes of Hsp70-2 expression in the monkey cryptorchid testis. The level of Hsp70-2 mRNA decreased slightly, while the expression of HSP70-2 protein was almost unchanged at the early stage of germ cell apoptosis in the cryptorchid testis on d 5 and dropped dramatically along with the loss of apoptotic germ cells in the cryptorchid testis on d 10 after operation. It is therefore suggested that Hsp70-2 might not take part in inhibiting the apoptosis of germ cells at the early stage during operation-induced cryptorchid testis, and that Hsp70-2 gene does not belong to the immediate early related gene responsible for germ cell apoptosis induced by heat stress.     

17beta-estradiol stimulates proliferation of spermatogonia in experimental cryptorchid mice

Aim： To investigate whether estrogen stimulates the proliferation of spermatogonia or induces spermatogenesis in cryptorchid mice. Methods： Mice were surgically rendered cryptorchid, then treated with different doses of 17β- estradiol （E2） s.c. once a day. Mice were killed at sexual maturity （45 days of age）, and histological analysis and inununofluorescence were performed. Serum follicle stimulating hormone （FSH）, estradiol, testosterone and luteinizing hormone （LH） were measured. Results： Low doses of E2 had no notable effect on spermatogonia, but at higher doses, E2 stimulated the proliferation of spermatogonia. Conclusion： E2 has a dose-related mitogenic effect on spermatogonia.     

Enrichment and transplantation of spermatogonial stem cells

Spermatogenesis is a complex, highly organized process originated from stem cell spermatogonia. Because there are very few stem cells and they can only be defined by their function, the identification and isolation of these cells has been very difficult. By using a spermatogonial transplantation assay system, we have identified α₆-and β₁-integrin expression on stem cells, and cells isolated with these antigens were significantly enriched in stem cells. This is the first demonstration of spermatogonial stem cell-associated antigens. Analysis of two infertile mouse models, Steel/Steel^Dickie (Sl/Sl^d) and experimental cryptorchidism, showed that the number of stem cells is reduced in Sl/Sl^d testis. Whereas cryptorchid testes are greatly enriched for stem cells, and one in 200 cells is a stem cell. These techniques will provide an important starting point for further purification and characterization of spermatogonial stem cells.     

Study on antisperm autoimmunity in experimental cryptorchid rats

Study on antisperm autoimmunity in experimental cryptorchid rats     

p53、p63在SD大鼠隐睾中的表达

目的 探讨p53、p63在SD大鼠隐睾中的表达及其在隐睾所致生精障碍过程中的可能作用.方法 本实验将30只健康雄性SD大鼠随机分为隐睾组和假手术组,建立单侧隐睾模型.术后7天脱颈椎处死大鼠,留取各组大鼠双侧睾丸称湿重,常规组织学切片观察各组睾丸生精上皮形态,免疫组化分别检测p53、p63蛋白表达的变化.结果 术后第7天,与正常侧睾丸相比,隐睾侧睾丸重量明显减轻,生精小管内生精细胞排列紊乱,生精细胞与精子的数量减少,可见较多多核巨细胞;免疫组化显示p53在各组睾丸的生精小管的各级生精细胞的胞质中均有表达,尤其是在精母细胞胞质中,但在隐睾中表达最强;p63在假手术组表达较少且较弱,而在隐睾组中表达较多且较强.结论 隐睾能导致睾丸内p53、p63表达增高,从而促进生精细胞凋亡增加.     

实验性隐睾大鼠的抗精子自身免疫研究

目的　探讨大鼠隐睾模型中抗精子自身免疫的发生情况及其对双侧睾丸的影响。方法　将 2 2日龄SD雄性大鼠 2 4只随机分为隐睾组和假手术组各 12只 ,在日龄 110天时采血并处死。用ELISA法检测血清抗精子抗体 (AsAb) ,免疫组化 (SABC法 )检测睾丸组织的IgG复合物 ,并对睾丸生精功能进行评价。结果　隐睾组和假手术组的血清AsAb阳性率分别为 41.7%和 0 ,差异有显著性 (P <0 .0 5 ) ;隐睾组大鼠的隐睾及对侧睾丸的生精功能评分均显著低于假手术组的手术侧及对侧睾丸 (隐睾侧P <0 .0 0 1,对侧P <0 .0 5 ) ,隐睾组大鼠的睾丸组织IgG复合物的沉积程度与生精功能呈负相关 (隐睾侧r =- 0 .860 ,P <0 .0 0 1,对侧r =- 0 .693 ,0 .0 1

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Immunostaining for placental alkaline phosphatase on fine-needle aspiration specimens to detect noninvasive testicular cancer: a prospective evaluation in cryptorchid men

OBJECTIVE: To assess, in a 12-year prospective study, the potential for early detection of testicular carcinoma in situ (CIS) by immunocytochemistry, using anti-placental alkaline phosphatase (PLAP) monoclonal antibodies on testicular fine-needle aspiration cytology (FNAC) specimens taken from a group of formerly cryptorchid patients, as such men are at greater risk of developing testicular cancer. PATIENTS AND METHODS: Sixty-eight men who had had orchidopexy at the Urological Department of the University of Padova between 1975 and 1983 were evaluated first in 1993, by a protocol including a history, physical examination, testicular ultrasonography and serum tumour markers, to eliminate the presence of testicular cancer. In 57 of the 68 men, specimens taken from bilateral testicular FNAC were stained immunocytochemically using anti-PLAP monoclonal antibodies. After 8 years, the same protocol was repeated on the 57 men, and the follow-up was prolonged until March 2005 for men with previous positive PLAP immunostaining. RESULTS: In 1993, six of the 57 men, (10.5%) had unilateral positive immunostaining for PLAP. By 2001, none of these men had developed testicular cancer, while of the other 51 men, only one developed a nonseminomatous tumour. The uninterrupted surveillance of PLAP-positive men showed no overt cancer until March 2005. CONCLUSION: The present findings do not seem to confirm the reliability of PLAP immunostaining of testicular specimens from FNAC for detecting CIS. These findings might depend on the geographical variability of both CIS and testicular cancer incidence, as well as on the variable relationship between CIS and successive occurrence of invasive testis cancer.     

Effect of cryptorchidism on testicular and Leydig cell androgen production in the mouse

Unilateral cryptorchidism was induced surgically in adult mice and the effects on testicular and Leydig cell steroidogenesis were studied after 7 weeks. There was a 60% reduction in weight of the cryptorchid testis and this was associated with a significant reduction in intratesticular androgen content, both under basal conditions and following an injection of hCG. Testicular androgen production in vitro was also significantly lower in the cryptorchid testis compared to the scrotal testis, again under both basal conditions (29 +/- 6% of control) and in the presence of hCG (46 +/- 9% of control). Scrotal testes from the unilaterally cryptorchid animals did not show any significant difference in steroidogenic capacity compared to testes from untreated control animals. The decrease in steroidogenic capacity of the cryptorchid testis was due, at least in part, to a reduction in activity for each Leydig cell. In four experiments, androgen production by Leydig cells isolated from cryptorchid testes was 48 +/- 9% of cells from scrotal testes in the presence of a saturating dose of hCG. Under basal conditions the effect was more variable between experiments with steroid secretion by Leydig cells from cryptorchid testes being 58 +/- 32% of that for cells from scrotal testes. Leydig cell steroidogenesis in the scrotal testes of unilaterally cryptorchid animals did not differ significantly from untreated controls. These results show that induced cryptorchidism in the mouse causes a significant reduction in Leydig cell activity. This is apparently different from the effects of this procedure on the rat and raises the possibility that intratesticular regulation differs between the two species.     

Plasma Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) Suppression in the Cryptorchid Ram by a Non-Steroid Factor (Inhibin) from Ram Rete Testis Fluid

Cryptorchid rams were bled every 15 or 30 min for 25 h. 20 ml of charcoal treated RTF were injected at the 5th and at the 6th h after the beginning of sampling. Human serum albumin or γ-globulin were injected similarly as controls. FSH, LH, testosterone and prolactin were measured by radioimmunoassay. A non-steroid factor from RTF suppresses the secretion of both FSH and LH but with different kinetics. FSH is progressively lowered after the first injection and a plateau (30% of depletion) is observed about 8 h after the first injection and lasts for about 7 h. RTF injections result in the suppression of LH peaks for 3 to 5 h starting at the first two h after treatment.