超声波对小白鼠生精上皮的影响

用功率为５Ｗ／ｃｍ２、频率为１．１０ＭＨｚ的超声波照射小白鼠睾丸５分钟（实验组１）、１０分钟（实验组Ⅱ），分别于处理后２４小时，４８小时及７天时间切取睾丸组织，制作石蜡切片，在光镜下观察生精上皮的组织学变化并与对照组进行比较。结果显示：（１）小白鼠睾丸经超声波照射后，曲细精管萎缩，管径变小；生精上皮变薄，精子发生时相消失；生精细胞减少，没有精子形成。（２）超声波照射１０分钟对生精上皮的损伤比照射５分钟更为严重。（３）超声波照射后２４小时，生精上皮即受到破坏，精子细胞减少；照射后４８小时，上皮受损伤的程度增大；照射后７天时间，曲细精管的组织学结构开始恢复，但仍无精子形成。（４）超声波对生精上皮的影响主要限于精母细胞、精子细胞和精子，而精原细胞与支持细胞没有明显变化。上述结果表明，超声波能够抑制小白鼠的精子发生，该抑制作用可能可逆。     

Sperm membrane protein (hSMP-1) and RanBPM complex in the microtubule-organizing centre

hSMP-1 is a human sperm membrane protein expressed during development. It is a testis-specific component produced during male germ cell differentiation. Proteins that interact with hSMP-1 were identified by the application of the yeast two-hybrid system. One of the components, RanBPM, was found to be associated with hSMP-1 under both in vitro and in vivo conditions. In the human testis, RanBPM is produced in spermatogonia and primary spermatocytes, suggesting expression during the early stages of spermatogenesis; whereas in the rat testis, it is located in round and elongated spermatids, similar to hSMP-1, suggesting expression of both components during spermiogenesis. Images obtained by immunofluorescence and confocal scanning microscopy of CHO-K1 cells co-transfected with pEGFP-C1-hSMP-1 and pDsRed1-Nl-RanBPM revealed that RanBPM and hSMP-1 are distributed in discrete loci throughout the cytoplasm. When superimposed, the stained spots appeared as congruent yellow areas, indicative of co-localization and probable complex formation of these two components. This interaction between hSMP-1 and RanBPM may be involved in the process of male germ cell differentiation. In CHO-Kl cells transfected with pEGFP-Cl-hSMP-1, the exogenously expressed hSMP-1 was found to co-localize with -tubulin. Depolymerization of microtubules can be induced in CHO-Kl cells by cold treatment. In cells transfected with the pEGFP-Cl vector, the dispersed tubulins promptly reassembled upon warming. However, in cells transfected with pEGFP-Cl-hSMP-1, reassembly of the dispersed tubulins was blocked even upon rewarming of the cells. These findings suggest that hSMP-1 interacts with tubulins and thereby may modulate microtubule assembly and/or activity.Abbreviations RanBPM Ran binding protein in the microtubule organizing centre - hSMP-1 Human sperm membrane protein - MBP Maltose binding protein     

尼莫地平、精氨酸对环孢霉素A血药浓度和睾丸毒性的影响

目的 :研究尼莫地平和精氨酸对环孢素 A(Cs A)血药浓度和睾丸毒性的影响。方法 :将 80只大鼠分为 4组进行实验 :N组 ,正常对照组 ;A组 ,Cs A2 0 m g/ kg.d- 1 ;B组 ,Cs A2 0 mg/ kg· d- 1 +精氨酸 2 g/ kg· d- 1 ,C组 ,Cs A2 0 m g/ kg· d- 1+尼莫地平 40 0 μg/ kg· d- 1 。每天腹腔注射给药 ,连续 3周后取血及睾丸测定 Cs A浓度 ,按抗精子发生效应积分评定法作生精功能的评价 ,测定曲细精管直径及作病理学检查。结果 :血药浓度 B组明显高于 A组 (P <0 .0 5 ) ;A、B、 C三组睾丸的精子发生明显障碍 ,而 B、C组比 A组的精子发生障碍要轻 (P <0 .0 5 ) ,曲细精管的直径 A、B、C三组明显小于 N组 (P <0 .0 5 ) ,但 B组大于 A组 (P <0 .0 1)。结论 :Cs A影响睾丸的生精功能 ,精氨酸和尼莫地平能明显降低 Cs A对睾丸的毒性作用 ,而精氨酸能提高血中 Cs A的浓度     

金黄地鼠精子发生及附睾成熟过程中Ca~（2＋）的分布规律

应用焦锑酸钾原位沉淀法对金黄地鼠精子发生及附睾成熟过程中Ｃａ２＋的分布变化规律进行了系统的研究。在睾丸的曲细精管中，支持细胞和生精细胞的细胞核和细胞质有钙沉淀颗粒分布。在支持细胞、精原细胞、精母细胞、高尔基体期和顶体期精子细胞的胞质中钙沉淀主要分布于线粒体和内质网。支持细胞核仁的无定形部分、核仁相随染色质和核质中有大量的钙沉淀颗粒。在精原细胞、精母细胞、高尔基体期的精子细胞核中钙沉淀主要分布于浓缩的染色质周围及其内部，而分散的染色质中则少见钙沉淀。在顶体期的精子细胞核内钙沉淀主要分布于核膜上，核质中偶见Ｃａ２＋沉淀。成熟期的精子细胞钙沉淀颗粒分布于顶体外膜和顶体内膜的内侧，顶体内膜上有钙沉淀集中分布。在附睾中钙沉淀分布于精子顶体区的质膜内外两侧和顶体外膜外侧，精子尾部线粒体外膜和基质中也有钙沉淀分布。     

人类胚胎发育、精子发生与DNA甲基化关系的研究进展

表观遗传是指基因的核苷酸序列不发生变化,但基因表达却发生了可遗传的改变。DNA甲基化是表观遗传重要的调控机制,它参与了动物胚胎发育、基因印迹和X染色体失活等过程,在基因表达的调控中具有重要作用。DNA甲基化可引起基因组中相应区域染色质结构变化,使染色质高度螺旋化,凝缩成团,失去转录活性。现对DNA甲基化与人类胚胎发育与精子生成的关系等进行综述。     

Specific expression of the mRNA for 25 kDA heat-shock protein in the spermatocytes of mouse seminiferous tubules

 The 25 kDa heat-shock protein (Hsp25) is a member of the family of small heat-shock proteins. We investigated the expression and cellular localization of Hsp25 mRNA in the testis of adult and developing mice using Northern blotting and in situ hybridization techniques. In the early postnatal days, i.e., before the onset of spermatogenesis, no Hsp25 mRNA was detected in the testis. At around 10 days postpartum, Hsp25 mRNA began to be expressed in the testis in coincidence with the onset of the first wave of spermatogenesis and increased in amount progressively toward adulthood. Throughout the testis development, the signal for Hsp25 mRNA was localized exclusively to germ cells and was not detected in Sertoli or interstitial cells. The testis of W/Wv mutant mice, which lack the germ cell line, exhibited no Hsp25 mRNA expression. In the testis of normal adult mice, the abundance of Hsp25 mRNA differed among the seminiferous tubules in different stages of spermatogenesis. The most intense signal for Hsp25 mRNA was localized to the spermatocytes at leptotene, zygotene and early pachytene phases, which are present in the tubules of stages I–III and IX–XII. The signal decreased in intensity in the late pachytene and diplotene spermatocytes and was not detected in spermatids. Spermatogonia were also devoid of the signal. These results suggested that Hsp25 plays some specific role in the meiotic prophase of the testicular germ cell. Accepted: 27 Oct 1998     

Hyperactivation of early steps of spermatogenesis compromises meiotic insufficiency in men with hypergonadotropism. A possible quantitative assay for high FSH/low testosterone availabilities

It has been shown previously that blood plasma elevation of FSH is associated with an impaired function of the seminiferous tubules. In the study presented here quantitative analysis of the seminiferous epithelium was performed in testicular biopsies of men with qualitatively complete spermatogenesis and hypergonadotropism (HG group, n = 6) or normogonadotropism (NG group, n = 9). Hormonal determinations were performed also in eight men with Sertoli cells only (SCO group). Plasma levels of gonadotropins found in HG were comparable with those found in SCO, while mean plasma testosterone levels in these patients were significantly lower than in SCO or NG. A significant decrease in the mean number of spermatids was present in HG, while the mean numbers of B spermatogonia (0.6 +/- 0.2) and preleptotene spermatocytes (0.6 +/- 0.1) were significantly elevated in comparison with NG (0.4 +/- 0.1 and 0.3 +/- 0.2, respectively). In all men with HG a GnRH test (100 micrograms i.v.) was performed and the relative increase of plasma FSH (maximum/basal level) correlated positively with the number of A-pale (r = 0.85, P less than 0.05) and B spermatogonia (r = 0.81, P less than 0.05). In NG group basal levels of FSH correlated with A-pale (r = 0.90, P less than 0.001) and B spermatogonia (r = 0.59). It seems that FSH plays a role to maintain the number and the differentiation rate of spermatogonia in men and is responsible for the hyperactivation of spermatogonia when secreted in excess. Hyperactivation of spermatogonia probably develops to compensate quantitative decrease in gamete production.(ABSTRACT TRUNCATED AT 250 WORDS)     

环磷酸腺苷应答元件调节器与精子发生

环磷酸腺苷应答元件调节器(CREM)是cAMP信号途径中的一个主要成分,CREM基因敲除导致小鼠不育,精子发生停止在减数分裂后的精子变态(spermiogenesis)的第一步,减数分裂后的生殖细胞特异的基因表达显著减少,凋亡细胞增多。而CREM突变雌鼠能育,说明CREM对于小鼠精子发生是必须的;同样在精子发生停止在圆形精子阶段的患者中发现CREM基因表达减少或不表达或剪接错误导致产生不正确的产物。本综述主要讨论CREM在精子发生中的作用。     

二次白消安腹腔注射致小鼠精子再生模型的建立

目的 建立一种小鼠精子再生模型.方法 采用不同剂量白消安(单剂10 mg/kg、20 mg/kg和间隔24 d二剂10 mg/kg)小鼠腹腔注射,分别于给药后第一、二、三、四、六、八周取材,进行光镜和电镜观察.二次给药组采用免疫组化检测生精细胞Ki-67表达,TUNEL标记法检测生精细胞凋亡.结果 间隔24 d二剂10 mg/kg白消安对生精上皮的损伤效应介于单剂10 mg/kg和20 mg/kg之间.第二次给药后2周,生精上皮仅基底部残留以单个型精原细胞(As型)为主精原细胞和支持细胞;第三周As型精原细胞增多;第四周分化精原细胞和精母细胞出现;6～8周出现精子发生,生精上皮结构逐步恢复正常.二次给药后1～2周生精细胞凋亡指数显著高于对照组(P＜0.01),以后逐步下降,至第六～八周恢复至对照组水平(P＞0.05).精原细胞Ki-67阳性率在第一～二周最低,在第三周最高,第四周开始下降,第六～八周与对照组无显著差异.结论 间隔24 d二次白消安(10mg·kg-1·次-1)腹腔注射可建立小鼠精子再生模型,诱导凋亡为白消安致生精细胞损伤的重要机制.二次给药后3周主要为精原干细胞增殖期,4周为分化期,6～8周为精子发生恢复期.