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Srinivasan Vijayaraghavan Dale D. Hoskins 《Molecular reproduction and development》1988,20(3):343-352
Secretions from the mammalian epididymis contain proteins that bind to developing sperm and are presumed to play a role in sperm maturation. The biochemical functions in sperm of most of these proteins are not known. In this report we describe the presence of a low molecular weight compound in bovine caudal epididymal luminal fluid (CF) that has a potent stimulatory effect on calcium (45Ca2+) uptake in immature caput epididymal spermatozoa. The studies were initially undertaken to characterize the effect of the protein caltrin, present in bovine seminal plasma (BSP), on calcium uptake into caput spermatozoa. Caltrin is known to block calcium influx into mature bovine sperm. Unexpectedly, the kinetics of calcium uptake into caput sperm showed a biphasic response when treated with BSP, namely, a stimulation of uptake at 1 to 5 min and inhibition of uptake after this time. Since caudal sperm do not show this biphasic response, we reasoned that BSP contained a factor derived from CF that must interact with developing sperm before the binding of caltrin to sperm can prevent further calcium uptake. We first demonstrated that preincubation of caput sperm with CF eliminated the biphasic calcium uptake effect induced in caput sperm by BSP and that caudal fluid alone had a potent stimulatory effect on calcium uptake in caput sperm. Half-maximal stimulation (fivefold over control) occurred at a caudal fluid protein concentration of 0.27 mg/ml. Partial purification of the factor indicates that it is of low molecular weight (MW ~ 1,000), but further chemical characterization has not been carried out and its epididymal site of origin is not known. The results indicate that the regulation of intracellular calcium levels in sperm differs in immature and mature bovine sperm in that an epididymal factor promotes calcium uptake during epididymal maturation, and the seminal fluid protein caltrin prevents it at ejaculation. 相似文献
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Background Vestigial remnants of the mesonephric duct and paramesonephric duct are well-known developmental abnormalities of the human testis and epididymis.
Methods and results During routine macroscopic and histological examination of four cynomolgus macaques, three different forms of testicular and epididymal appendages were observed, namely a unilateral appendix testis, a bilateral appendix epididymidis, and several vasa aberrantia. By histological and immunohistochemical examinations it could be demonstrated that both the appendix testis and the appendix epididymidis consisted of a central fibromuscular core and a pseudostratified columnar epithelium at the outer surface. The vasa aberrantia were attached to the connective tissue sheaths of the epididymis/testis and were represented by small duct-like or cystic structures internally lined with a simple cuboidal to columnar, partly ciliated epithelium.
Conclusion Awareness of these rudimental tissues in non-human primates is necessary to determine actual incidence rates in non-human primate species used in toxicological research and avoids misdiagnosing during routine necropsy and histological examinations. 相似文献
Methods and results During routine macroscopic and histological examination of four cynomolgus macaques, three different forms of testicular and epididymal appendages were observed, namely a unilateral appendix testis, a bilateral appendix epididymidis, and several vasa aberrantia. By histological and immunohistochemical examinations it could be demonstrated that both the appendix testis and the appendix epididymidis consisted of a central fibromuscular core and a pseudostratified columnar epithelium at the outer surface. The vasa aberrantia were attached to the connective tissue sheaths of the epididymis/testis and were represented by small duct-like or cystic structures internally lined with a simple cuboidal to columnar, partly ciliated epithelium.
Conclusion Awareness of these rudimental tissues in non-human primates is necessary to determine actual incidence rates in non-human primate species used in toxicological research and avoids misdiagnosing during routine necropsy and histological examinations. 相似文献
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Tabuchi Y Toyama Y Toshimori K Komiyama M Mori C Kondo T 《Biochemical and biophysical research communications》2005,329(3):812-823
A conditionally immortalized epididymis caput cell line, MEPC5, was established by infecting primary cultured mouse epididymis caput cells with a temperature-sensitive simian virus 40 large T-antigen. At a permissive temperature of 33 degrees C, the large T-antigen was expressed and the cells grew continuously. However, the downregulation of T-antigen at a nonpermissive temperature of 39 degrees C and the upregulation of cell density at 33 degrees C were associated with growth arrest and the increased protein expression of p21(waf1), a cell cycle inhibitor. The cells expressed epididymal caput-expressed genes such as phosphatidylethanolamine binding protein, polyoma enhancer activator 3, ME1, sulfated glycoprotein-2 (SGP-2), androgen receptor, and retinoic acid receptor alpha. Interestingly, the expression levels of ME1 and SGP-2 were significantly elevated under the cell growth-restricted conditions. The established mouse epididymis caput epithelial cell line MEPC5 retains some characteristics of differentiated epididymis epithelial cells, and should prove an excellent model for studies of gene expression and the physiological functions of epididymis caput epithelial cells. 相似文献
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Expression of a glutamate transporter (EAAC1), a lipocalin (MEP17) and -galactosidase (-Gal) in histological sections was used to monitor post-natal development of the murine epididymis. Three epithelia in the adult caput of wild-type mice were distinguished: I, the initial segment; II, the proximal caput; and III, the distal caput. The regions in which epithelia I, II and III were situated were called regions I, II and III, respectively. Regions I, II and III developed from a precursor epithelium present on day 14; from day 16, a presumptive region I epithelium was evident and, by day 21, epithelia characteristic of future regions II and III appeared. The relationship between the c-ros gene and the initial segment was studied by investigating the development of the caput epididymidis in transgenic homozygous c-ros
knockout (–/–) mice that lack the initial segment, heterozygous (+/–) males and wild-type males in which the efferent ducts had been ligated prepubertally so that the initial segment failed to develop. In mice with prepubertally ligated efferent ducts, regions II and III developed normally but region I was missing in the adult and expression of c-ros was partially decreased. In (–/–) mice, the precursor epithelium was present, differentiation of epithelium II was delayed until day 32 and epithelium I never developed. Thus, caput region I develops before c-ros expression, high testosterone secretion and differentiation of regions II and III but not if the organ is deprived of the oncogene c-ros or testicular exocrine secretions. The caput of the knockout male lacks solely the initial segment so that the efferent ducts are in continuity with the post-initial segment, proximal caput region. The ligand for c-ros
may be present in testicular fluid and both ligand and receptor may be necessary for differentiation of epithelia I and II.This work was funded by the Deutsche Forschungsgemeinschaft (the male gamete: production, maturation, function, FOR 197/3-1) 相似文献
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通过双向电泳结合质谱技术分离鉴定正常成年大鼠附睾头段与尾段管腔液中的蛋白组成,从附睾头段及尾段管腔液的22个差异蛋白点中鉴定出12个蛋白质.其中11个蛋白质在不同种属哺乳动物的附睾组织中已有鉴定报道,而过氧化物酶6(peroxiredoxin 6,Prdx6)为新发现的存在于附睾头段及尾段管腔液中的体液蛋白.采用RT-PCR、Western印迹及免疫组化技术,对该蛋白在大鼠附睾中的表达及分布进行了分析.实验表明,Prdx6与精子的成熟、贮存及保护有一定关系,其具体机制值得进一步深入研究. 相似文献
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