【作者】 康友敏；

【导师】 段相林；

【作者基本信息】 河北师范大学 ， 动物学， 2003， 硕士

【摘要】 雄性哺乳动物的睾丸具有生精和分泌雄性激素等重要的功能。睾丸微循环担负着氧、激素、营养物质及代谢产物的供给和运输任务，以维睾丸正常生理机能。微循环指由微动脉到微静脉间的细微血管的血循环，微血管是微循环的结构基础。血睾屏障是睾丸内毛细血管与精小管之间存在的屏障结构。血睾屏障对精子的正常发生及雄性生殖功能的维持具有重要的作用。目前对睾丸的研究多限于病理和临床，且多集中于人或动物的成年阶段，对于其发育与衰老变化的系统研究，国内外报道很少。本文采用血管铸型、扫描电镜、透射电镜、免疫组化及体视学分析等方法对不同年龄大鼠睾丸微血管构筑、eNOS分布及血睾屏障的变化进行了系统的研究，以期为睾丸生理、病理学、老年生物学和临床应用提供理论、形态学及动物实验方面的依据。 本研究以SD大鼠为实验材料，按照其生长发育的特点分为：初生组(生后1天)、3周龄组(离乳期)、3月龄组(成年期)、12月龄组(开始衰老)、18月龄组(衰老期)和24月龄(衰老期)六组，每组30只大鼠，实验结果进行统计分析。结果如下： 1．微血管分布：大鼠睾丸的微血管分布于睾丸间质内。从初生组到12月龄组微血管分布很规则；到18月龄组排列变得疏松；24月龄组生精小管周围的微血管排列不规则。随着增龄，单位面积内微血管数目逐渐增多；管壁也明显增厚；微血管数与生精小管数的比值从初生后到3月龄逐渐增大，从3月龄到24月龄呈减小的趋势。 2．成年期微血管构筑：睾丸动脉由腹主动脉发出后，沿精索下行绕至睾丸腹侧形成3-4个螺旋状蟠曲后，进入睾丸实质内。睾丸动脉发出睾丸微动脉进入睾丸小隔，分支进入睾丸小叶内，在生精小管周围形成绳梯状毛细血管网，然后汇合成毛细血管后微静脉和睾丸微静脉，一部分微静脉汇合成蔓状静脉丛，一部分直接进入精索。 3．微血管构筑的增龄变化：3周龄组睾丸动脉在实质内已形成了管周微动脉和管间微静脉，但绳梯状的毛细血管网尚未形成；3月龄组与12月龄组微血管构筑呈中文摘要现定的构烈特点，在生精小管周围形成绳梯状的毛细血管网:18月与24月龄组苹丸萎缩，微而管构筑变得不很规则。随着增龄，微血管管径旱增人趋势，微动脉管径小J“微静脉。 4.eNOS表达与微血管通透性:初生组人鼠翠丸内eNOS阳性表达极少;3周龄flll阳宝勺).J皮细，泡、l’llJ质细!饱及枯J代细胞均出现了阳性表达:3月龄组生精小管靠近若腔的精r细胞出现eNOS阳性，阳性血管内皮细胞数目增多显著:12月到24月龄阳性l阳乍今内皮细胞数I]‘.‘增多的趋势。本文首次发现精母细胞只在24月龄出现了。\(巧1;1{性农i返_微1111扮通透性从3周龄至3月龄’l’增人趋势，12月龄到24月龄纤微l阳粉通透性:，减小趋仑 5.血梁屏障:随着增龄，毛细血怜内皮细胞的基膜由薄、断续、电子密度不均逐渐发展为基脱垮、完招、.毯子密度较高而均匀，厚度逐渐增加。从初生到成熟期内皮细饱质膜小泡逐渐增多，衰老期则逐渐减少;随着增龄，生精小管基膜逐渐加泞一:初’t和3周龄纠人鼠支持细胞间未见紧密连接.3月龄组可见典型的紧密连接，!2)l’少}抖1」龄fl1可见支持细胞间不典型的紧密连接，24月龄纸未见到紧密连接。 结论: 1.微血管分布的变化:辜丸微血管分布于翠丸间质内。本文发现随着翠丸的发育，微而竹数日增多，间质内增多的微血管能够提供其发育精子产生所需的营养。随石架丸的老化，单位面积内翠九内的微血管持续增多，管壁增厚，血液运输及物质交换功能卜降二:J一能会影响‘攀丸的生精功能。单位面积内的微血管数与生精小管数的比俏在3月龄处于峰值，表明此时微血管的分布及血液供应处于最佳状态，衰老期比值卜降农l归微血管的血_液供应效率卜降，可能是造成翠丸老化的重要原因。 2.成年期微血管构筑:成年人鼠翠丸的微血管人多数彼此吻合成网状，为生精小管提供了丰富的营养和必要的激素水平:呆丸实质内绳梯状的毛细血管网，使甸个’1二精小竹都能得到充分的营养和激素供应:翠丸内的动脉迂曲走行共同维持翠丸低于体内3一5℃的适宜温度，使精子止常产生。 3.微血管构筑的增龄变化:随着月龄的增加，翠丸微血_管构筑变化显著，微血管管径.产增加的趋势。3周龄己经形成了简单的微血.管构筑，jJ’人鼠性成熟提供了微循环良好的结构从础。成年期策丸实质内形成的绳梯状毛细血管网为翠丸旺盛生枯功能提供了保阶。衰老期微血管走行紊乱，微血管出现很多迂曲，可能是造成辜丸衰老的重要原因之一。随着增龄，微血_管密度和微血管管径旱增人趋势，微动脉竹径小】几微静脉，有利于而液与架丸组织的物质交换。气中文摘要 4.N0对微血管通透性的影响:本文发现从初生到3周龄eNOS阳性内皮细胞数!}‘l‘增加的趋协，表明人鼠发育时期eNOS催化合成生理水平的NO。NO可能会促进‘粉俐的分泌，加快枯J’的产’!几，有利J一人鼠的性成熟。成年期翠丸内N0浓度基本稳定。仔[得注意的是衰老期架丸eNOS催化合成的NO持续增加，NO通过调l丁血流与血jt一会使微lh1管内皮细胞的通?更多还原

【Abstract】 The mammiferous testis perform important functions of producing sperm and secreting male hormone. The capillary vessel of testis which is a part of Blood-Testis Barrier transports oxygen, hormone and nutriment in order to maintain normal function. Microcirculation is the blood circle from arterile to venule. Blood-Testis Barrier is the harrier between capillary vessel and seminiferous tubule which is important to produce sperm and maintain male procreation function. At present, The research limit in pathology and clinic of adult human or animal and need more study on developing and aging animal. In our experiments, the morphological alterations of testis microvascular architecture, eNOS distribution and Blood-Testis Barrier at different ages had been observed by microvascular corrosion casting technique, SEM, TEM, immunohistochemical method and morphometry. These results were not only theoretically important but also practically valuable in physiology, pathology, aging biology, morphology and so on.The experiment materials were SD rats. According to their developmental characteristics, we selected six groups of rats: postnatal 1 day, postnatal 3 weeks, postnatal 3 months, postnatal 12 months, postnatal 18 months and postnatal 24 months.Each group included 30 rats.The results of the experiments were analyzed with the software of STAT on computer.The results were as follows:l.The microvascular distribution : The capillary vessel of rat testis were distributed among seminiferous tubules. The capillary vessel were distributed regularly in testis from postnatal I day to postnatal 12 months, and loosely in postnatal 18 months rat, and irregularly in postnatal 24 months rat. The capillary vessel number in every unit area increased and the microvascular wall incrassated gradually with aging.The number ratio between capillary vessels and seminiferous tubules were on the trend of increase from 3 weeks to 3 months and decrease from 3 months to 12 months.2. Testicular microvascular architecture of adult rat: Testicular arteries emitedparrelling branchs which became arterile and formed twist bends into testis parenchyma. Then the arterile eminted intertubular capillaries and peritubular capillaries forming rope-ladder-like pattems.Then the venule were collected and became testis veins, then mass into rete venosum, finally some venule formed pampiniform plexus and others entered into varicosity.3.Changes or Testicular microvascular architecture: Testicular capillary vessel formed intertubular capillaries and peritubular capillaries.but donot formed rope-ladder-like patterns capillary net in postnatal 3 weeks. There were rope- ladder-like patterns capillary nets around seminiferous tubules in postnatal 3 and 12 months. Testicular microvascular architecture became irregularly in postnatal 18 and 24 months with testis atrophing.The diameter of capillary vessel increased with aging. The diameter of arterile was less than that of venule.4.Influence of NO on microvascular permeability: Specimens from postnatal 1 day showed little immunoreactivity for eNOS. In contrast, blood vessel endothelium and Leydig cells and spermatids in postnatal 3 weeks testes were strongly expressed eNOS.The number of positive blood vessel endothelium, Leydig cells and spermatids in postnatal 3 months was conspicuously increased. In postnatal 12 and ISmonths testes, the number of postive cells persistently increased.In 24 months testes, some spermatocytes also displayed strong eNOS immunoreactivity. From 3 weeks to 3 months, the permeability of microvascular was on the trend of increase while it was on the trend of decrease from 12 months to 24 months.S.BIood-Testis Barrier: The basal lamina of endothelium cells developed from thin, broken and unequal electronic density to thick, full and high electronic density with aging. The number of plasmalemmal vesicle increased from young to adult and decreased gradually in old age. The basal lamina of seminiferous tubules thickened gradually with aginy. . There uas not tight junction betwee更多还原