大剂量PGE对大鼠生精作用及组织PG含量的影响

PGE每天3.0mg/kg皮下注射22天,除使大鼠付睾精于活率下降、畸形率升高外,也可损伤生精细胞,最敏感者为早期精子细胞和初级精母细胞,偶尔损及精原细胞。对间质和支持细胞无明显影响。给大剂量PGE后,大鼠血浆和肾皮质PGE水平无明显改变,而睾丸组织中则显著升高。     

Preclinical evaluation for noninvasive reversal following long-term vas occlusion with styrene maleic anhydride in langur monkeys

A preclinical evaluation for reversal through a noninvasive approach following long-term vas occlusion with styrene maleic anhydride (SMA) has been attempted in langur monkeys at the level of semen parameters, sperm functional tests, semen biochemistry, histology and ultrastructure of reproductive organs, hematology and serum clinical biochemistry including antisperm antibodies (ASA), prostate-specific antigen (PSA) and testosterone. Noninvasive reversal through palpation, percutaneous squeezing and electrical stimulation, forced vibratory movements and suprapubic percussion in the inguinal segments and per-rectal digital massage was attempted in seven langur monkeys after 540 days following vas occlusion. The results revealed instant azoospermia reversal on the same day of reversal with impaired sperm quality, which showed gradual improvement and normospermia with normal motility and viability after 60-90 days of reversal. Sperm functional tests, including ultrastructure of spermatozoa, indicative of sterility in the initial ejaculations, reached normalcy after 90-120 days of reversal. The seminal plasma biochemistry indicative of obstructive azoospermia regained a normal pattern after 90-120 days of reversal. The morphology of testes that showed focal degeneration during 540 days of vas occlusion and that of vasa deferentia that showed exfoliation of epithelial cells resumed to normal morphology comparable with control animals after 150 days of reversal. The morphology of the epididymis, seminal vesicle and prostate did not show appreciable changes following vas occlusion and after noninvasive reversal compared with those of control animals. Hematology, serum clinical chemistry, ASA, PSA and testosterone fluctuated within control limits, indicating safety of the procedure at the level of accessory reproductive organs. The results suggest that noninvasive reversal is feasible even after long-term vas occlusion with SMA and is safe without adverse side effects.     

Frequency of stages of the seminiferous cycle in the thick-tailed bush baby (Otolemur garnetti), a prosimian primate: possible phylogenetic implications?

Spermatogenesis in the thick-tailed bush baby, Otolemur garnetti, was studied using light microscopy. The stages and stage frequencies of the cycle of the seminiferous epithelium were determined using semithin sections stained with methylene blue-azure II. These sections were obtained from the testes of six healthy adult males (n=6). They revealed 11 stages of the seminiferous epithelial cycle in this species. The mean relative frequencies of the stages I–XI were 10.9, 6.0, 5.9, 7.3, 13.2, 10.7, 11.7, 9.2, 7.6, 8.9 and 8.6, respectively. Comparisons were made between the frequency data in the thick-tailed bush baby and equivalent data in the rat, hamster, macaque, baboon, chimpanzee and man. There was a significant correlation (P<0.05) between the Otolemur data and equivalent stage frequency data of two rodent species (rat and hamster) and monkey (Macaca arctoides). However, there was no significant correlation between the present data and those of the baboon, chimpanzee and man. Possible phylogenetic implications of these findings are discussed.     

The effects of orchidopexy and orchidectomy on testes of rats subjected to ipsilateral abdominal testis with vas deferens obstruction

An experimental study was planned to evaluate and compare the effects of orchidopexy and orchidectomy on the testes of rats subjected to unilateral abdominal testis with vas deferens obstruction. Four groups were established. Rats in the control group underwent a sham procedure. While the testis was maintained in the abdomen with the vas deferens ligated for 8 weeks in group 2, rats in groups 3 and 4 underwent orchidopexy or orchidectomy after 4 weeks. Remaining testes were harvested at the end of the 8-week period. Testis and body weights were obtained during harvest. Samples were evaluated through DNA flow cytometry, and percentages of haploid cells were determined. Groups were compared through unpaired t-test, and p-values less than 0.05 were considered significant. All three treatments had decreased testis weight over body weight values of ipsilateral testes. Ipsilateral orchidectomy increased the value among contralateral testes. However, none of the groups had a contralateral testicular value less than the sham-operated group. All three treatments decreased the percentage of haploid cells among ipsilateral testes, but only an abdominal testis was associated with a decrease in the percentage of haploid cells among contralateral testes. Maintaining a testis with an obstructed vas deferens in the abdomen for 8 weeks damages both ipsilateral and contralateral testes. Orchidopexy, while showing amelioration of the ipsilateral testis, spares the contralateral testis as well as orchidectomy. Orchidopexy for an undescended testis with vas deferens obstruction is a rational approach.     

Effects of the chronic use of dehydroepiandrosterone (DHEA) on testicular weight and spermatogenesis: Experimental study in rats

Aim: The complete biological effects of chronicuse of dehydroepiandrosterone (DHEA), reportedas a weak androgen, are not completelyunderstood. The aim of the present study is toevaluate the effects of chronic administrationof DHEA on the spermatogenesis in rats.Methods: Male Wistar rats, 4 months old, wereselected for the study. The animals weredivided into two groups. Group 1 (n = 9) receivedplacebo (saline solution) 0.5 ml/day and Group2 (n = 15) received DHEA 5 mg/kg/day. Both thegroups received the respective treatments 5days a week during 10 months. At the end of theexposure, the rats were sacrificed and thetestes removed, weighed and processed forhistologic analysis. Spermatogenesis wasevaluated as the mean number of seminiferoustubules with and without spermatids inmaturation phase in their lumen, in fiverandom fields on the same slide.Results: The median levels of serum totaltestosterone and dehydroepiandrosterone sulfatewas measured in the two groups. Significanthigher concentrations in total testosterone(2.06 ± 0.4 vs. 0.80 ± 0.2; p < 0.05) andDHEAS (222.1 ± 41.5 vs. 2.0 ± 0.3) wereobserved in the group treated with DHEA ascompared to the control group. The mean weightsof the right testes were 1.59 ± 0.3 ingroup 1 and 1.58 ± 0.2 g in group 2(p > 0.05). These values for the left testeswere 1.57 ± 0.3 and 1.55 ± 0.3 g,respectively (p > 0.05). The histologicanalysis showed a mean of 13.5 ± 1.5 and12.8 ± 1.8 seminiferous tubules per field inthe groups 1 and 2, respectively (p > 0.05).The same analysis demonstrated that in thecontrol group 0.06 ± 0.1 of the tubulespresented without spermatids in maturationphase and in the DHEA group this was observedin 0.22 ± 1.2 of the tubules (p < 0.05).Conclusion: Chronic administration of DHEA inthe present dose did not show any detectableeffect on the quantitative and qualitativeanalyses of spermatogenesis in rats.     

高压氧对精索静脉曲张家兔附睾组织学影响的实验研究

目的研究高压氧(HBO)对精索静脉曲张(VC)家兔附睾组织学的影响,探讨精索静脉曲张导致男性不育的发病机制。方法采用HBO干预精索静脉曲张家兔模型,对睾丸、附睾的重量,附睾不同节段精子活力,附睾的组织形态以及精液参数进行研究。结果与未行HBO干预的VC模型比较,HBO 干预后的VC模型精液质量明显改善,睾丸、附睾重量明显增加(P值均<0．01),左侧附睾尾部Ⅱ级以上精子明显增加(Ⅱ级57．43％±6．48％,Ⅲ级2．91％±1．51％)(P<0．01,<0．05)。附睾上皮结构改善,腔内精子密度增加。结论 VC可导致附睾病理损害、精子成熟和获能障碍。慢性缺血、缺氧及其微循环障碍是导致附睾病理损害、精子成熟和获能障碍的主要机制。HBO可有效抑制VC致附睾的病理损害进程。     

Lactational fenvalerate exposure permanently impairs testicular development and spermatogenesis in mice

Fenvalerate, a widely used synthetic pyrethroid insecticide, has been associated with poor semen quality in human being. However, little is known about the effects of lactational fenvalerate exposure on testicular development and spermatogenesis. The purpose of the present study was to investigate the effects of maternal fenvalerate exposure during lactation on testicular development and spermatogenesis in male offspring. Maternal mice were administered with fenvalerate (60 mg/kg) by gavage daily from postnatal day (PND) 0 to PND21. Lactational fenvalerate exposure markedly decreased the absolute and relative weights of testes and increased the number of apoptotic cells in testes of pups at weaning. Histological examinations showed abnormal seminiferous tubules with large vacuoles or complete spermatogenic failure in testes of fenvalerate-treated mice at weaning. Additional experiment showed that lactational fenvalerate exposure markedly reduced mRNA and protein levels of testicular P450scc, a testosterone (T) synthesis enzyme. Consistent with down-regulation of testicular P450scc, the level of serum and testicular T at weaning was significantly decreased in pups whose mothers were exposed to fenvalerate during lactation. Although the expression of testicular P450scc and serum and testicular T in adulthood restored to control level, the decreased weight of testes and histological changes were irreversible. Importantly, the percentage of mature seminiferous tubules (stages VII and VIII) and the number of spermatozoa were obviously decreased in adult male mice whose mothers were exposed to fenvalerate during lactation. Taken together, these results suggest that lactational fenvalerate exposure permanently impairs testicular development and spermatogenesis.     

大鼠精子发生过程中热休克蛋白70-2特异表达的研究

目的运用蛋白质组学方法,寻找大鼠精子发生相关蛋白质,找到目标蛋白质后,进一步用免疫组织化学方法做定位研究。方法用重力沉降法(STAPUT法)从9 d龄雄性大鼠睾丸中分离出A型精原细胞,从成年的雄性大鼠睾丸中分离出粗线期精母细胞、圆形精子细胞。分别提取这3种细胞的总蛋白质,进行双向电泳。对所得双向电泳凝胶扫描,分析并找出差异蛋白质。对挑选出的差异蛋白质做质谱分析,发现在这3种不同细胞的表达上有明显差异的蛋白。进一步做睾丸免疫组织化学组织定位、定量研究。结果双向电泳结果显示,HSP70-2在粗线期精母细胞、圆形精子细胞中表达量较高, 在A型精原细胞则表达量极少。HSP70—2在粗线期精母细胞中表达量最大。用HSP70—2抗体对大鼠睾丸组织切片行免疫组织化学研究,发现粗线期精母细胞、Sertoli细胞、Leydig细胞有阳性颗粒反应。HSP70—2主要表达于细胞质。结论 HSP70—2在精子发生过程中有明显的差异表达,推测其对精子发生起重要调节作用。     

Role of the spermatogenic–Sertoli cell interaction through cell adhesion molecule-1 (CADM1) in spermatogenesis

Endocrine and local secretory factors have long been known to be required for spermatogenesis. Evidence has been accumulating in recent years indicating that direct contact between spermatogenic and Sertoli cells is also required for spermatogenesis. Cell adhesion molecules of various types have been found in the mammalian testis that are expressed in spermatogenic and/or Sertoli cells and involved in homophilic and/or heterophilic binding. We have cloned a novel cell adhesion molecule, cell adhesion molecule-1 (CADM1), also known as immunoglobulin superfamily 4A or spermatogenic immunoglobulin superfamily, from the mouse testis. CADM1 belongs to the immunoglobulin superfamily and is composed of three immunoglobulin-like domains, a transmembrane domain, and a short intracellular domain. In the seminiferous epithelium, CADM1 is expressed in intermediate spermatogonia through to early pachytene spermatocytes as well as in elongating spermatids—but not in round spermatids, mature spermatozoa, or Sertoli cells. One of the heterophilic binding partners of CADM1 has proven to be a poliovirus receptor, another member of the immunoglobulin superfamily that is expressed in Sertoli cells. Knockout mice for CADM1 develop male infertility due to defective spermatogenesis. These findings suggest that cell adhesion molecules between spermatogenic and Sertoli cells play essential roles in spermatogenesis.     

Lonidamine affects testicular steroid hormones in immature mice

The effects on the hypothalamus-pituitary-testicular axis of the well-known antispermatogenic drug lonidamine (LND) has not been elucidated so far. In the present study, the possible changes of the testicular steroid hormones were evaluated in immature mice for a better characterization of the LND adverse effects both in its use as antitumoral agent and male contraceptive. Male CD1 mice were orally treated on postnatal day 28 (PND28) with LND single doses (0 or 100 mg/kg b.w.) and euthanized every 24 h from PND29 to PND32, on PND35 and on PND42 (1 and 2 weeks after the administration, respectively). Severe testicular effects were evidenced in the LND treated groups, including: a) significant testis weight increase, 24 h and 48 h after dosing; b) sperm head counts decrease (more than 50% of the control) on PND29-32; c) damage of the tubule morphology primarily on the Sertoli cell structure and germ cell exfoliation. All these reproductive endpoints were recovered on PND42. At the same time, a significant impairment of the testicular steroid balance was observed in the treated mice, as evidenced by the decrease of testosterone (T) and androstenedione (ADIONE) and the increase of 17OH-progesterone (17OH-P4) on the first days after dosing, while the testicular content of 17beta-estradiol (E2) was unchanged. The hormonal balance was not completely restored afterwards, as levels of T, ADIONE and 17OH-P4 tended to be higher in the treated mice than in the controls, on PND35 and PND42. These data showed for the first time that LND affects intratesticular steroids in experimental animals. However further data are needed both to elucidate the mechanism responsible for the impairment of these metabolic pathways and to understand if the androgens decrease observed after LND administration could be partially involved in the testicular damage.