Physiological significance of nitrergic transmission in human penile erection

The corpora cavemosa (CC) muscles of the human penis and their structural arrangements are essential for the physiology of erection. Contraction of this muscle causes detumescence, and relaxation, tumescence. The motor excitatory neurotransmission is adrenergic, acting through the alpha adrenoceptors. Continuous adrenergic transmitter (noradrenaline) release is necessary for the maintenance of non-erectile (contractile) state of the penis. The inhibitory neurotransmitter that relaxes CC muscle to produce erection is nitrergic i.e., the chemical messenger being nitric oxide (NO). The latter can also be released from cavernous endothelium. Presence of NO increases intracellular cGMP through activation of the enzyme guanylate cyclase. This causes relaxation of CC muscle. Phosphodiesterase type 5 (PDE5) is responsible for the degradation of cGMP and regulation of CC muscle tone. Specific PDE inhibitors such as sildenafil enhance the intracellular cGMP to improve erection. Increase in intracellular cAMP can also bring about pharmacological erection in man (eg. PGE1, papaverine and histamine). Inhibition of excessive adrenergic tone with appropriate alpha - adrenergic blocking agents (eg. phentolamine) can also contribute to the onset of pharmacological erection. ( Asian J Androl 2000 ; 2 : 51 - 56 )     

实验性精索静脉曲张大鼠附睾分泌蛋白的鉴定研究

目的　研究精索静脉曲张对附睾合成与分泌蛋白的影响 ,鉴定病理状况下附睾特异改变的蛋白成分。　方法　部分结扎左肾静脉建立实验性左侧精索静脉曲张大鼠动物模型。用 SDS-PAGE和双向电泳分离左附睾尾匀浆上清中的蛋白质组分 ,切下稳定出现改变的蛋白质所在的条带或斑点 ,进行胶内胰蛋白酶消化 ,酶解得到的最终肽混合物进行肽质量指纹谱测定。通过检索互联网上的蛋白质数据库确定该蛋白的可能成分。　结果　与对照动物相比 ,实验性左侧精索静脉曲张大鼠左附睾尾匀浆上清中一分子量约2 0× 1 0 3、等电点约 5.5的蛋白成分明显增加。经质谱分析结合网上数据库检索表明 ,该蛋白是附睾视黄酸结合蛋白。　结论　实验性左侧精索静脉曲张导致大鼠附睾中视黄酸结合蛋白含量升高 ,这一改变对精子在附睾中成熟及精子功能的影响有待进一步研究     

The Effect of Non-Union of Testis and Epididymis and of Cryptorchidism on the Development of Epididymis and Ductus Deferens in the Rat/Der Einfluß der Separation von Hoden und Nebenhoden und des Kryptorchismus auf die Entwicklung von Nebenhoden und Ductus deferens bei der Ratte

16-days old rats were operated with either uni- or bilateral ligation of ductuli efferents and separation of testis and epididymis to the level of the inferior epididymal artery (non-union operation), induction of cryptorchidism or bilateral sham operation. The epididymides were weighed and the epididymides and deferent ducts were examined with light- and electron-microscopy at days 30, 37, 44 and 58. Bilateral non-union operated epididymides and cryptepididymides had a significantly lower weight increase than controls, but the histology and diameter of epididymal tubules were unchanged. This indicates a true growth retardation and reduced length of epididymal tubules of non-union operated and cryptepididymides. For bilateral operations a positive correlation was found between the weight of epididymis and plasma levels of total testosterone as reported earlier. Unilaterally operated epididymides had a weight development significantly below contralateral controls, despite normal plasma levels of testosterone. It is concluded that the reduced-weight of unilaterally operated epididymides is the result of diminished local androgen stimulation from the ipsilateral testis. Non-union of testis and epididymis may have pathogenetic significance in maldescent of testis by a retarded growth of the ductal system.     

大鼠精索静脉曲张后附睾上皮细胞凋亡及管腔α-1,4-葡糖苷酶、唾液酸含量观察

目的:探讨大鼠左侧精索静脉曲张后同侧附睾上皮细胞凋亡与附睾管腔中-α1,4-葡糖苷酶和唾液酸含量改变的关系及意义。方法:16只雄性SD大鼠建立左侧精索静脉曲张模型,分为对照组和实验组,每组8只。缺口末端转移酶标记技术检测附睾上皮细胞凋亡;硝基酚法和5-甲基苯二酚法分别检测附睾管腔液-α1,4-葡糖苷酶和唾液酸含量。结果:大鼠左侧精索静脉曲张模型建立后的第7 d,实验组同侧附睾上皮细胞凋亡指数显著高于对照组(P<0.001);实验组附睾管腔液-α1,4-葡糖苷酶、唾液酸含量显著低于对照组(P<0.05,P<0.005)。结论:大鼠左侧精索静脉曲张可导致同侧附睾上皮细胞凋亡增加,进而影响该侧附睾上皮细胞的合成和分泌功能。     

大鼠睾丸扭转复位后附睾唾液酸含量变化及意义

目的 :探讨大鼠睾丸扭转 2h和 4h复位后 2 4h附睾唾液酸含量的变化和意义。　方法 :用 2 4只雄性SD大鼠建立左侧睾丸扭转复位模型 ,分为对照组、扭转 2h组和 4h组 ,每组 8只。 5 甲基苯二酚法检测扭转侧附睾唾液酸的含量。　结果 :睾丸扭转 2h复位后 2 4h扭转侧附睾唾液酸含量 [(2 3.385± 9.2 2 0 )mg/mgprot]改变不明显 ;睾丸扭转 4h复位后 2 4h附睾唾液酸含量 [(13.72 5± 7.80 1)mg/mgprot]下降明显 (P <0 .0 5 )。　结论 :睾丸扭转 2h复位后 2 4h附睾分泌唾液酸功能不受影响 ,扭转 4h复位后 2 4h附睾分泌唾液酸功能下降 ;附睾耐受缺血再灌注损伤的时间可能较长。     

L-肉碱在奥硝唑所致大鼠睾丸和附睾损伤中的保护作用

目的:探讨L-肉碱(LC)在奥硝唑(ORN)所致大鼠附睾和睾丸损伤中的的保护作用。方法:40只雄性SD大鼠(200～230g)随机均分为5组:①A组:给予0.5%的羧甲基纤维素钠(溶剂)灌胃;②B组:每天给予400mg/kgORN灌胃;③C组:每天给予800mg/kgORN灌胃;④D组:每天给予[ORN(400mg/kg)+LC(100mg/kg)]灌胃;⑤E组:每天给予[ORN(800mg/kg)+LC(100mg/kg)]灌胃。上述各组均连续灌胃20d,末次给药24h后,所有大鼠麻醉后处死,分别取睾丸、附睾,进行称重和HE染色,计算睾丸、附睾系数并观察睾丸和附睾病理组织学改变。结果:①与A组相比,B组睾丸、附睾系数明显降低(P<0.05);而C组睾丸、附睾系数为极显著性降低(P<0.01);D组与A组相比无差异,E组与A组相比有极显著性差异(P<0.01);②HE染色显示,与A组相比,B组睾丸生精小管内各级生精细胞排列基本整齐,部分生精小管管腔内有脱落的生精细胞,附睾管腔中精子数目下降,有时可见散在的生精细胞;C组大鼠睾丸生精小管管腔内均可见坏死脱落的生精细胞,附睾管腔中精子数目明显减少,且有较多的非精子细胞成分。D组睾丸生精小管无明显改变,附睾管腔中精子数目也未见明显下降;E组睾丸生精小管管腔内精子数目减少,可见坏死脱落的生精细胞,附睾腔中精子数目明显减少,并伴有较多的非精子细胞成分。结论:奥硝唑(ORN)可导致雄性大鼠附睾和睾丸病理组织学改变,LC对ORN引起大鼠附睾和睾丸损伤具有一定的保护作用。     

大鼠附睾尾部的精子参数与灌服昆明山海棠乙醇提取物后的改变及其抗生育效果观察

本文报告３７只Ｗｉｓｔａｒ成年大鼠附睾尾部的三项精子参数值及季节等因素对精子参数的影响，并与每日灌服昆明山海棠乙醇提取物ＴＨ５（１１６ｍｇ／ｋｇ）３０天后的２ｌ只大鼠的改变及生育力进行比较。结果表明：对照组大鼠左、右侧附睾尾部的三项精子参数值虽各不相等但无明显差异（Ｐ＞０．０５），与ＴＨ５组停药２０天后剖检的大鼠相比，上述各项精子参数值间有极显著差异（ｐ＜０．０１），且所有服药大鼠完全丧失生育力；对照组于４～６月剖检的大鼠其精子明显低于１～３和９～１２月剖检的大鼠；用于生殖研究的大鼠的体重＞４００ｇ或睾丸容积＞３．５ｍｌ、＜１．０ｍｌ均可对精子质量有不良影响；至于停服ＴＨ５７０天后剖检的大鼠，其精子参数值和生育力与对照组无异。     

荧光酶法测定大鼠附睾精子ATP含量

参照ＬＫＢ公司新的ＡＴＰ测定法，测定了大鼠附睾精子ＡＴＰ含量，并比较了大鼠附睾头、尾部精子ＡＴＰ含量的差别及活动精子百分率的关系。结果表明，附睾尾部活动精子百分率和ＡＴＰ含量均明显高于附睾头部的精子     

Distribution of Mahoganoid protein its mRNA in the testes and epididymides of mature male rats]

OBJECTIVE: To localize the Mahoganoid protein and Mahoganoid mRNA in the testes and epididymides of mature male rats. METHODS: Testes and epididymides obtained from mature male SD rats (n = 20) were fixed by 4% poly formaldehyde and sliced for immunohistochemical (IHC) test and in situ hybridization (ISH) test, respectively, for detecting Mahoganoid protein and Mahoganoid mRNA. RESULTS: In both the 2 tests, clear brown staining was observed in Leydig cells, spermatogonia, primary spermatocytes, spermatids, Sertoli cells, and peritubular myoid cells. Both the Mahoganoid protein and its mRNA were mainly located on cell membrane and cytoplasm. And in the epididymis tissues, the Mahoganoid protein and Mahoganoid mRNA were respectively expressed within the membrane and cytoplasm of principal cells, basic cells and epithelial cells. CONCLUSION: Both Mahoganoid protein and Mahoganoid mRNA are expressed in the male rat reproductive system and localized in Leydig cells, Sertoli cells, spermatogenic cells and epithelial cells. They play an important role in spermatogenesis but their physiological significance remains to be clarified.     

Mahoganoid蛋白及其mRNA在大鼠睾丸和附睾中的表达

目的:探讨M ahoganoid(Md)蛋白及其mRNA在成熟大鼠睾丸和附睾组织中的表达。方法:健康成年SD大鼠20只,取睾丸和附睾组织4%多聚甲醛固定,石蜡切片,用免疫组化SP法和原位杂交方法分别检测Md蛋白及其mRNA在睾丸和附睾组织中的表达。结果:免疫组化SP法显示:睾丸组织间质细胞、睾丸生精小管管周肌样细胞和各级生精细胞(精原细胞、初级精母细胞和精子细胞)、支持细胞呈阳性反应,Md蛋白主要表达于胞膜及胞质。在附睾组织,棕色免疫阳性反应物质可见于输出管的高柱状细胞、低柱状细胞的胞膜及胞质,以及附睾管的高柱状细胞、主细胞、基细胞的胞膜及胞质。其中,在附睾尾部的上皮细胞中仅见微弱的棕色免疫阳性反应物质。原位杂交方法显示:睾丸组织间质细胞、睾丸生精小管管周肌样细胞和各级生精细胞(精原细胞、初级精母细胞和精子细胞)、支持细胞上也均有Md mRNA阳性棕色颗粒杂交信号,主要表达于胞膜及胞质。在附睾组织,Md mRNA阳性棕色颗粒杂交信号也均可见于高柱状细胞、主细胞、基细胞的胞膜及胞质。结论:Md蛋白及其mRNA在成熟大鼠睾丸和附睾组织中均有表达,其生理功能尚有待阐明。     

Sperm structural and motility changes during aging in the Brown Norway rat

The Brown Norway rat provides a useful model to study aging of the male reproductive tract because of the selective age-dependent pathological changes that are found in the testis, epididymis, and prostate. In the testis, there is a clear age-dependent decrease in both steroidogenesis and spermatogenesis. In the epididymis, some striking segment-specific changes occur at the histological and biochemical levels prior to the major loss of spermatogenesis. We hypothesized that formation of spermatozoa in the testis and maturation of spermatozoa in the epididymis (ie, acquisition of motility and loss of the cytoplasmic droplet) may be altered during aging. Changes in the morphology of spermatozoa were assessed by light and electron microscopy. Using computer-assisted sperm analysis, the motility parameters of spermatozoa obtained from the caput and cauda epididymidis of young and old Brown Norway rats were compared. In old animals, we also compared the motility of spermatozoa from epididymides adjacent to regressed testes with those from epididymides adjacent to nonregressed testes. There was a marked increase with age in the number of spermatozoa with abnormal flagellar midpieces; the nature of these defects did not change with age. In caput epididymidis, the percentage of motile sperm was similar in young and old rats. In contrast, the percentage of motile spermatozoa was significantly decreased in cauda epididymidis of old rats; spermatozoa from the regressed testis side had altered motility characteristics. Furthermore, in the cauda epididymidis on the regressed testis side of aged Brown Norway rats, the proportion of spermatozoa that retained their cytoplasmic droplet was markedly elevated. Some of these effects are likely due to changes taking place in spermatozoa during the process of spermatogenesis in the testis (eg, formation of the flagellum), whereas others could occur during sperm maturation in the epididymis (eg, acquisition of motility). The multiple effects of aging on sperm morphology, the acquisition of motility, and the shedding of the cytoplasmic droplet clearly indicate that the quality of spermatozoa is affected by aging.     

Attractin蛋白在大鼠睾丸和附睾中的免疫组织化学定位

目的 :探讨Attractin蛋白在成熟大鼠睾丸和附睾组织中的分布。　方法 :健康成年雄性SD大鼠 2 0只 ,灌流取睾丸和附睾组织固定 ,石蜡包埋和冰冻切片。用免疫组化法和间接免疫荧光方法检测Attractin蛋白在成熟大鼠睾丸和附睾组织中的表达。　结果 :睾丸组织间质细胞、睾丸精曲小管管周肌样细胞和各级生精细胞 (精原细胞、初级精母细胞和精子细胞 )、支持细胞呈阳性反应 ,主要表达于胞膜及胞质。睾丸间质细胞表达略强于生精细胞。附睾头、体、尾均未见表达。　结论 :Attractin蛋白在成熟大鼠睾丸组织间质细胞和生精细胞中有较强的表达 ,其生理功能尚有待进一步探讨。     

High-intensity focused ultrasound ablation of the epididymis in a canine model: a potential alternative to vasectomy

BACKGROUND AND PURPOSE: High-intensity focused ultrasound (HIFU) is a noninvasive technology capable of inducing thermal coagulative necrosis of subsurface structures without injuring intervening tissues. We have previously reported on the feasibility of HIFU vasectomy in a canine model. In this study, we evaluated the feasibility of HIFU ablation of the canine epididymis as an alternative to vasectomy. The epididymis may be a better target than the vas deferens because it is larger, more easily positioned in the HIFU focal zone, and more susceptible to occlusive injury at lower energy levels, thus reducing collateral damage. MATERIALS AND METHODS: A hand-held HIFU clamp was used to grasp the epididymides of anesthetized dogs (eight surgically exposed and six grasped transcutaneously). An ultrasound transducer in the clamp focused energy on a 1 x 3 x 8-mm target zone centered between the clamp jaws. Ultrasonic energy (6-19 W) was delivered to this target zone for various times (16-150 seconds). The vas, epididymis, and testis were harvested for histologic examination 2 weeks after ablation. RESULTS: Seven of the eight epididymides ablated after surgical exposure demonstrated histologic findings associated with occlusion (fibrosis, hemorrhage, and proximal duct dilatation). Five of the six epididymides ablated transcutaneously also demonstrated histologic evidence of occlusion. Skin burns were evident overlying three epididymides, and one testicular injury was noted adjacent to an ablated region of the epididymis. CONCLUSION: High-intensity focused ultrasound ablation of the epididymis causes injury and histologic changes associated with epididymal occlusion. Further investigations are under way to optimize ablation parameters and to confirm azoospermia with ejaculate studies. Refinement of this technology may provide a rapid noninvasive alternative to conventional vasectomy.     

S-adenosyl-L-methionine decarboxylase activity in the rat epididymis: ontogeny and androgenic control

The authors describe the occurrence of high levels of S-adenosyl-L-methionine decarboxylase (SAMDC) activity in the rat epididymis, and its ontogeny and androgenic control. As early as 15 days of age, SAMDC activity exists, although a peak of activity is observed at 25 days. Bilateral orchidectomy resulted in a decline of epididymal SAMDC activity. However, an androgen-independent fraction, accounting for 34% of total activity, appears to exist in the epididymis. In 45-day-old orchidectomized rats, SAMDC activity was stimulated by testosterone treatment in a dose-dependent manner. However, treatment of 45-day-old intact animals with a high dose of the androgen failed to modify SAMDC activity, indicating that, at this age, the enzyme is maximally stimulated by endogenous androgens. The observed effect of testosterone on castrated rats was completely abolished by concomitant treatment with the antiandrogen flutamide. This compound was ineffective on the androgen-insensitive fraction. To assess the contribution of circulating and luminal androgens to the maintenance of epididymal SAMDC, rats were unilaterally orchidectomized and activity was determined in both epididymides after 7 days. The SAMDC activity was identical in epididymides from both sides, suggesting circulating androgens suffice to maintain normal levels of activity. It was concluded that androgens regulate epididymal SAMDC activity, although an androgen-independent fraction appears to exist.     

Expression and distribution of OCTN2 in mouse epididymis and its association with obstructive azoospermia in juvenile visceral steatosis mice

AIM: L-carnitine, an essential cofactor for mitochondrial, beta-oxidation of long-chain fatty acids, is known to play important roles in sperm maturation and metabolism when spermatozoa pass and acquire motility in the epididymis. We reported that obstructive azoospermia occurred in the epididymis in the juvenile visceral steatosis (JVS) mice, which are OCTN2 dysfunction mice caused by mutations in the gene encoding OCTN2, have been used for animal models of primary systemic carnitine deficiency. The aim of present study is to investigate the expression of OCTN2 protein in the mouse epididymis and its relation between the localization of OCTN2 and obstructive azoospermia in JVS mice as animal models for human male infertility. METHODS: Animals used in this study were wild-type (C57BL/6 J) mice (n = 4) and JVS mice (n = 4). We made a specific polyclonal antibody against OCTN2 and examined immunohistochemically the localization of OCTN2 in the mouse epididymis. RESULTS: OCTN2 was localized on the apical membrane of the principal cells of distal corpus and cauda epididymides. Immunocytochemistry demonstrated that OCTN2 was localized on the surface of microvillus upon the principal cells. In JVS mice, immunoreactivity started in a region immediately distal to where the sperm obstruction occurred. CONCLUSIONS: Our results suggest that OCTN2 functions as a carnitine transporter between the epithelium and the lumen in distal corpus and cauda epididymides and provides a clue as to why obstructive azoospermia is induced in distal parts of epididymis.     

有机阳离子转运子2在人类附睾中的表达及其意义

目的:研究人类附睾有机阳离子转运子2(OCTN2)mRNA的表达,探讨附睾肉碱转运机制,为探索男性避孕节育新技术提供理论依据。方法:应用RT-PCR方法检测人类附睾头、体、尾组织中OCTN2 mRNA的表达。结果:人类附睾头、体、尾组织中都存在OCTN2 mRNA表达。结论:人类附睾可能依赖OCTN2转运肉碱进入附睾管,为精子提供能量,促进精子成熟。对人类附睾OCTN2的进一步研究,将成为男性节育研究中新的分子靶标。     

Animal models for epididymoepididymostomy. Development of an alternative microsurgical procedure for vasoepididymostomy.

The present success rate for high level microsurgical vasoepididymostomy in patients with obstructive azoospermia is generally poor in comparison with more distal vasoepididymal bypasses, suggesting that the development of a high level bypass method which preserves the distal maturation and storage functions of the epididymis might increase the fertility success rate. To achieve this we have developed a segmental bypass of the distal caput-proximal corpus regions of the epididymis (epididymoepididymostomy) using the rat and rabbit as animal models. In this procedure the epididymides of 11 adult male Sprague-Dawley rats were exposed through a scrotal incision and a convolution of the duct in the proximal corpus region was attached to an opened convolution in the mid-caput epididymides using a standard microsurgical technique. Each male was rested for at least 3 months after the microsurgical bypass operation to allow the preoperative sperm contents of the caudal storage region to be replaced by post-bypass spermatozoa. Six of the 11 rats were proven fertile after surgery by siring litters from mating trials up to 11 months later. The patency of anastomoses was confirmed in 3 animals by laparotomy and recovery of large numbers of sperm with normal motility from the cauda epididymidis distal to the anastomosis site and also from the vas. Similar unilateral surgery in 2 adult male rabbits resulted in normal post-operative semen profiles in 1 and an in vivo fertilisation rate of 100% from 1 mating trial 8 months after surgery. The successful development of a reliable animal model for epididymoepididymostomy provides an experimental tool for studying the function of the epididymis. This technique may also have clinical application as an alternative to high level vasoepididymostomy in selected patients with obstructive azoospermia.     

【原创论文】小鼠杀菌渗透增强性蛋白起源于睾丸及附睾表达并定位于精子中

杀菌渗透增强性蛋白（BPI）是具有抗革兰氏阴性菌活性的内源性杀菌蛋白。在本研究中,我们通过自行制备的多克隆抗体,检测了BPI蛋白在小鼠出生后睾丸及附睾组织中的表达,以及在附睾精子头部的亚细胞定位。实验结果表明,睾丸和附睾均独立表达BPI基因。在附睾中,自起始段至尾部,BPI蛋白的表达水平递减,并逐步特异性富集于亮细胞的胞质中。在顶体反应前的顶体基质内可见BPI蛋白,应起源于睾丸表达;顶体反应后,可见BPI蛋白分布于整个精子头部质膜表面,尤其是赤道板区域,可能有睾丸或附睾表达的两种起源。我们的研究结果提示,BPI蛋白可能参与顶体反应前后精子质膜结构的调控,并参与后续的精卵融合过程。     

The role of cell adhesion molecules in ischemic epididymal injury

Objective The aim of this study was to investigate the role of adhesion molecules in epididymal injury induced by ischemia-reperfusion (I-R) in the rats. Study design About 20 male Sprague-Dawley rats were separated into two groups. A sham operation was performed in group 1 (control). In group 2 (I-R), following 6 h of unilateral spermatic cord torsion, 1-h detorsion of the testis was performed. Then, epididymides were removed to measure the tissue levels of malondialdehyde (MDA) and to make histological examination. Results Malondialdehyde values increased in group 2. In group 2, the rats demonstrated significant disorganization of the epithelium and loss of microvilli in the epididymal tissue. No abnormal microscopic findings of the epididymis of the rats in the control group. The tenascin expression in the interstitial area of the epididymis was intense in group 2. Intercellular adhesion molecule-1 (ICAM-1) expression by intense brown staining was seen along the basement membrane in epididymal tissue from I-R group rats. The microvillus sites of the epithelia in I-R group were stained mildly by lectin. Conclusion The increased expression of adhesion molecules found in epididymal injury induced during of postischemic reperfusion may implicate importance of inflammatory infiltration.