实验性精索静脉曲张大鼠生精状态评价

目的 通过对大鼠实验性精索静脉曲张(varicocele,VC)模型睾丸生精小管生精上皮结构、性激素水平的分析,探讨精索静脉曲张致不育的机制.方法 40只雄性青春期Wistar大鼠随机分为VC8周组(n=12)、VC12周组(13=12)和相应对照组(分别n=8);左肾静脉部分结扎建立实验性大鼠VC模型.术后8周或12周,分别测量各组大鼠:(1)左侧精索静脉直径、睾丸温度及体质量、睾丸生精小管生精上皮;(2)外周血中促卵泡刺激素(FSH)、黄体生成素(LH)和睾酮(T)的水平.结果 VC8周和VC12周组大鼠左侧精索静脉明显扩张,与对照相比血管直径差异有统计学意义(P<0.01);VC8和VC12周组大鼠左侧睾丸体质量均低于自体右侧睾丸和对照组睾丸,差异有统计学意义(P<0.05);光镜下,VC组大鼠双侧睾丸生精小管生精上皮精子发生阻滞、细胞脱落和细胞层数减少等,VC12周组损伤程度较VC8周组明显加重,左侧较右侧显著;与对照组相比,VC组大鼠外周血FSH、LH升高,T降低,差异均有统计学意义(P<0.01).结论 本研究提示:VC对大鼠双侧睾丸生精小管生精上皮产生明显的损害作用,并导致大鼠血中T水平降低和FSH、LH水平升高.     

佳蓉片对LOH大鼠睾丸形态结构与功能改善作用研究

目的:探讨佳蓉片对迟发性性腺功能减退症(LOH)大鼠睾丸形态结构与功能改善作用。方法:18月龄雄性SD大鼠随机分为模型组、佳蓉片组,2月龄雄性SD大鼠设为正常对照组,佳蓉片组给予0.375 g/(kg·d)体重剂量的佳蓉片灌胃,每天1次;正常对照组和模型组给予相同体积的蒸馏水灌胃,连续给药28 d。实验结束后对所有大鼠称重,取血清检测睾酮(T)含量,睾丸组织进行病理学及电镜检测。结果:与正常对照组相比,佳蓉片组、模型组大鼠睾丸系数显著降低(P均<0.05),模型组大鼠血清T水平:[(3.40±0.06)vs(5.88±0.46) ng/ml]显著降低(P<0.05);与模型组相比,佳蓉片组体重和睾丸系数差异无统计学意义(P>0.05),血清T[(4.50±0.78)ng/ml]显著升高(P<0.05)。佳蓉片组大鼠睾丸组织生精小管内精子数量增多,睾丸间质增多明显;电镜示线粒体数量明显增多,部分可见线粒体鞘,部分线粒体嵴清晰,线粒体水肿不明显。结论:佳蓉片能提高LOH大鼠T水平,改善大鼠睾丸组织形态和超微结构。     

高压氧下调精索静脉曲张大鼠睾丸组织NOS和NO表达的研究

目的:探讨精索静脉曲张(varicocele,VC)大鼠睾丸组织一氧化氮合酶(NOS)和一氧化氮(NO)含量的变化及高压氧(HBO)的干预效果。方法:选取50只7周龄雄性SD大鼠,随机抽取10只为假手术对照组(A组),其余40只部分结扎左肾静脉建立VC模型,8周后再将40只大鼠随机分为VC模型组(B组)和HBO干预的VC模型组(C组),C组用HBO对VC大鼠进行干预。实验结束后分别测定三组大鼠睾丸组织NOS及NO的含量。结果:B组左侧睾丸NOS、NO含量显著高于A组,C组左侧睾丸NOS、NO含量下降明显(P0.01);三组右侧睾丸NOS、NO含量比较,差异无统计学意义(P0.05)。结论:VC时睾丸NOS和NO含量的变化是造成睾丸损伤、生精障碍的原因之一,高压氧可能通过下调NOS、NO的表达来改善VC所致的生精功能障碍。     

营养性肥胖对青春期雄性大鼠睾丸发育过程的影响

目的:探讨以高脂饲料配方建立的营养性肥胖大鼠模型对青春期雄性大鼠睾丸发育过程的影响。方法:21日龄雄性清洁级SD大鼠80只,断奶适应性饲养3 d后,随机分为对照组(n=32)和实验组(n=48)。以高脂饲料建立营养性肥胖动物模型。观察喂养后第3、4、5、6周末(即鼠龄为6、7、8、9周)大鼠体重、Lee's指数、睾丸重量、附睾重量的变化;全自动生化分析仪检测外周血甘油三酯(TG)和总胆固醇(TC);全自动微粒子化学发光免疫分析系统检测血清T、E2;HE染色观察睾丸发育的形态学改变。结果:高脂喂养的实验组大鼠在第3周末平均体重已明显增加(P<0.05),至第6周末,实验组大鼠较对照组超重达26.6%(P<0.01),Lee's指数也明显大于对照组(P<0.01);实验组大鼠第5、6周末的睾丸系数下降明显(P<0.05);实验组每周龄大鼠血清TG,TC水平均比对照组明显升高;实验组每周龄大鼠的T水平均明显低于对照组(P<0.05),E2水平在第3、4、5周虽低于对照组,而在第6周则呈现明显增加趋势,且显著高于对照组(P<0.01);光镜下可见实验组大鼠睾丸生精上皮细胞排列紊乱,细胞层次减少,成熟的精子数量较少。结论:高脂、高能量饮食可诱发青春期雄性大鼠营养性肥胖,随着肥胖程度的逐渐加重,可造成睾丸发育不全、睾丸生殖内分泌功能障碍。     

新生期甲醛染毒对成年后大鼠雄性性行为、睾丸重量以及血清睾酮水平的影响

目的观察新生期甲醛染毒对成年后大鼠雄性性行为、睾丸重量和血清睾酮水平的影响。方法选用健康清洁级新生7日龄雄性SD大鼠24只,随机分为高剂量甲醛（10mg/m3）、低剂量甲醛（0.1mg/m3）染毒组和对照组3组,甲醛染毒14d后常规饲养4周至成年。然后分别观察成年后雄性大鼠的扑捉潜伏期（CLP）和60min内扑捉雌鼠的次数（CT）,称量睾丸重量以及利用放免法测定大鼠血清睾酮（T）水平。结果低剂量甲醛染毒组大鼠CLP,CT,睾丸重量以及血清睾酮含量与对照组相比没有明显差异。但高剂量甲醛染毒组大鼠的扑捉潜伏期（CLP）与对照组相比明显升高（P〈0.05）;60min内扑捉雌鼠的次数（CT）、睾丸重量与对照组相比均明显下降（P〈0.05）;大鼠血清睾酮水平与对照组和低剂量甲醛染毒组相比轻度下降。结论新生期甲醛染毒对成年后雄性大鼠性行为以及睾丸有一定的损伤作用,并且损伤具有剂量依赖性。     

血红素氧合酶2在去势大鼠阴茎海绵体内的表达

目的:研究去势大鼠阴茎海绵体血红素氧合酶2(HO-2)和内皮型一氧化氮合酶(eNOS)的表达,探讨雄激素与HO-2、eNOS在ED中的作用及相关性。方法:10周龄雄性SD大鼠40只,分为4、8、12周组和正常对照组各10只,实验组采取手术切除双侧睾丸,对照组采取假手术。分别于术后4、8、12周测定大鼠血清睾酮(T)、阴茎海绵体内压(ICP)、平均颈动脉压(MAP),取阴茎标本,采用Western印迹分析阴茎海绵体HO-2含量,免疫组化分析HO-2和eNOS的表达。结果:去势各组血清T水平较正常对照组显著下降(P<0.05)。经3V、5V电压刺激后去势各组ICP/MAP值明显下降(P<0.05)。HO-2在正常和去势大鼠阴茎海绵体组织均有表达,去势4周组HO-2光密度分布曲线下面积(341.50±99.70)较正常组(876±443.36)和去势8周组(705.00±152.74)明显下降(P<0.05),去势8周与正常组之间无显著变化(P>0.05),去势12周没有检测到HO-2的表达。eNOS主要表达于阴茎海绵体血管内皮细胞,去势组eNOS(123.94±30.23)较正常组(421.21±125.12)差异有显著性(P<0.05)。T与eNOS和HO-2表达呈高度正相关(r=0.976、0.946,P均<0.05)。结论:雄激素可能通过影响大鼠阴茎海绵体HO-2、eNOS的表达参与阴茎勃起功能调控。     

泡状棘球蚴感染对大鼠免疫学状态及移植心存活的影响

目的 研究肝泡状棘球蚴感染对大鼠免疫学状态及移植心存活的影响。方法 建立SD大鼠到Wistar大鼠的颈部异位心脏移植模型。对照组以未接种泡状棘球蚴的Wistar大鼠为受者；实验组以感染泡状棘球蚴的Wistar大鼠为受者。术后观察移植心的存活时间、组织病理学变化、心肌组织内T淋巴细胞和嗜酸粒细胞的浸润情况，测定血清内白细胞介素4（IL-4）和γ干扰素（IFN-γ）水平。结果实验组移植心的存活时间与对照组相比，差异有统计学意义（P〈0．05），组织病理学分级及心肌组织中CD4^＋T淋巴细胞数与对照组相比，差异无统计学意义，而CD8^＋T淋巴细胞数、嗜酸粒细胞数与对照组相比，差异均有统计学意义。发生排斥反应时，实验组血清内IL-4水平高于对照组，而IFN-γ水平低于对照组。结论 泡状棘球蚴感染造成TH1／TH2向TH2类细胞因子偏移，有利于移植物的存活，嗜酸粒细胞浸润可能是移植心发生排斥反应的原因之一。     

复方玄驹胶囊对去势雄性大鼠性激素水平及性器官重量的影响

目的:探讨复方玄驹胶囊对去势雄性大鼠性激素水平及性器官重量的影响。方法:采用随机分组、空白对照、模型对照的临床研究方法,从60只SPF级雄性幼年SD大鼠中,随机取出12只大鼠为正常对照组,余大鼠去势(摘除双侧睾丸)后,随机均分4组,分别为模型对照组、复方玄驹胶囊高、中、低剂量组。正常模型对照组予生理盐水灌胃,模型组采用复方玄驹胶囊配制液灌胃干预,20 d后,采用放射免疫法检测各组大鼠外周血液中睾酮(T)、黄体生成素(LH)和卵泡刺激素(FSH)水平,同时称取附睾、包皮腺、精囊腺、前列腺及提肛肌的重量。结果:①与正常对照组相比,去势各组T水平显著降低,说明造模成功。与模型对照组相比,复方玄驹胶囊高、中、低剂量组T水平明显升高,差异有统计学意义(P<0.01)。②与正常对照组相比,模型对照组、复方玄驹胶囊各剂量组LH水平显著升高,差异有统计学意义(P<0.05);FSH水平虽有所升高,但差异无统计学意义。③与正常对照组相比,模型对照组包皮腺、精囊腺、前列腺、提肛肌指数明显降低,说明造模成功;与模型对照组相比,复方玄驹胶囊高剂量组精囊腺指数明显提高,差异有统计学意义(P<0.05);而复方玄驹胶囊不同剂量组之间比较,包皮腺、前列腺、提肛肌指数均未见明显增加,差异无统计学意义(P>0.05)。结论:复方玄驹胶囊可改善雄性SD大鼠外周血中激素水平,提高附性器官指数,可能是临床治疗ED的重要作用机制之一。     

改进型左侧精索静脉曲张对大鼠睾丸酶及增殖细胞核抗原的影响

目的 观察改进型左侧精索静脉曲张(ELV)对大鼠睾丸酶及增殖细胞核抗原(PCNA)的影响.方法 利用改进的方法建立青春期SD大鼠左精索静脉曲张的模型21只;假手术组SD大鼠15只作对照组.术后3个月,取部分睾丸组织匀浆提取上清液,比色法定量检测乳酸脱氢酶(LDH)、琥珀酸脱氢酶(SDH)、葡萄糖-6-磷酸脱氢酶(G6PDH)活性,利用酶联免疫吸附试验(ELISA)测定PCNA的浓度.结果 实验组左睾丸内的LDH、G6PDH活性分别为(8.17±3.47)、(34.00±16.29)U/mg,与对照组同侧(11.98±2.26)、(54.88±20.87)U/mg比较下降,与实验组右睾丸(12.69±3.97)、(78.03±25.28)U/mg比较也下降,差异均有统计学意义(P<0.05);实验组左睾丸内的SDH活性(1.22±0.41)U/mg与对照组同侧(1.74±0.43)U/mg比较下降,差异有统计学意义(P<0.05),与实验组右睾丸(1.62±0.56)U/mg比较下降,差异无统计学意义(P>0.05);实验组左睾丸内PCNA(669.10±205.39)mU/ml与对照组同侧(776.81±231.72)mU/ml比较下降,和实验组右睾丸(800.81±172.02)mU/ml比较也下降.差异均无统计学意义(P>0.05).结论 改进型ELV致睾丸酶活性降底和PCNA的变化,这些变化可能是影响生育能力的因素之一.     

改进型实验性左侧精索静脉曲张的建立及其对大鼠卵泡刺激素及抑制素B的影响

目的:探讨改进型实验性左侧精索静脉曲张(ELV)对大鼠血清卵泡刺激素(FSH)及抑制素B(InhB)的影响。方法:利用改进的方法建立青春期SD大鼠左精索静脉曲张的模型30只;假手术组SD大鼠30只作对照组。术后3个月,取大鼠血清,ELISA法分别检测FSH、InhB的浓度。结果:实验组大鼠血清中FSH浓度[(37.56±9.72)ng/ml]与对照组[(26.69±5.33)ng/ml]相比升高,具有统计学意义(P<0.05);而实验组大鼠血清中InhB的浓度[(349.93±99.48)pg/ml]与对照组[(768.83±146.96)pg/ml]相比下降,具有统计学意义(P<0.05)。结论:改进型ELV致FSH升高及InhB下降,这些变化可能是影响生育能力的机制之一。     

Effects of varicocele on testosterone, apoptosis and expression of StAR mRNA in rat Leydig cells

The aim of this study was to explore the effects of varicocele on the morphology and function of Leydig cells in the rat testis. Forty male Sprague-Dawley rats were divided into two groups: the experimental group underwent surgery to create a left varicocele (VC), and the control group underwent a sham operation. Serum testosterone and intratesticular testosterone levels were measured using a radioimmunoassay after 4 and 8 weeks of operation. Leydig cells were studied for apoptosis and expression of steroidogenetic acute regulatory (StAR) protein mRNA levels. Serum testosterone levels declined after 4 and 8 weeks of operation but were not significant (P>0.05). However, the intratesticular testosterone levels after 8 weeks were significantly decreased compared with the control group (P<0.01). The mean apoptosis index of Leydig cells in the experimental group was significantly higher than that in the control group after 4 or 8 weeks (P<0.01). StAR mRNA levels in the Leydig cells of the experimental group were significantly lower compared to those of the control group (P<0.01). Our data show that varicocele did impair Leydig cell function by increasing apoptosis and suppressing the expression of the StAR protein.     

Reversibility of cyclosporine-induced hypoandrogenism in rats

In an attempt to determine whether the inhibition of the hypothalamic-pituitary-testicular axis induced by oral cyclosporine (CsA) is reversible, intact adult male rats were treated with 30 mg/kg oral CsA daily for 4 weeks, and then vehicle (orange juice) for the next 4 weeks. A second group of animals (control) was fed orange juice throughout the entire 8 weeks of the experiment. Serum testosterone (T) was decreased significantly (P less than 0.01) after 4 weeks of CsA treatment when compared with controls. After cessation of oral CsA for the next 4 weeks, there was no difference in serum T between the control and CsA-treated groups. Serum LH, intratesticular T, ventral prostate (VP) and seminal vesicle (SV) weights paralleled the serum T levels at 4 and 8 weeks--i.e., all values were decreased in the 4-week CsA-treated group when compared with controls, and these returned to normal at 8 weeks. Intratesticular 17 alpha-hydroxylase and 17,20-desmolase activities were significantly lower after 4 weeks of CsA treatment; following cessation of the CsA, these enzymatic values returned to normal within 4 weeks. These data demonstrate that at the duration of treatment and the dose studied, the CsA-induced inhibition of the hypothalamic-pituitary-testicular axis of the intact adult rat is completely reversible.     

Effect of testosterone on intracavernous pressure elicited with electrical stimulation of the medial preoptic area and cavernous nerve in male rats

We studied the effects of castration and testosterone (T) replacement on intracavernous pressure (ICP) elicited with electrical stimulation of the medial preoptic area (MPOA) and cavernous nerve (CN) in male rats. We measured the ICP during electrical stimulation of the MPOA and CN in castrated male rats with and without testosterone replacement. The experimental group consisted of 20-week-old male rats at 2 weeks (n=8), 4 weeks (n=8) and 8 weeks (n=8) after castration, and at 8 weeks after castration with T replacement (n=4). Intact 20-week-old rats (n=8) served as controls. The erectile response was expressed as the ICP/blood pressure (BP) ratio. The ICP/BP ratios during CN stimulation of the animals at 2, 4, and 8 weeks after castration were significantly lower than those of the intact animals. However, the erectile responses were not eliminated. In contrast to these peripherally evoked responses, erectile responses elicited by electrical stimulation of the MPOA were eliminated following castration. After testosterone replacement, both erectile responses were restored. Testosterone plays important roles in both the central and peripheral neural pathways for the maintenance and restoration of erectile capacity. The central control of erection shows more extensive changes following testosterone replacement than the peripheral control.     

Comparison of the antispermatogenic effects of a new D-homo-steroid and testosterone in rabbits

In comparison to testosterone, 18β-hydroxy-18α-methyl-16α, 17α-methylene-D-homo-5α-androstane-3-one (D-homo-S) shows more pronounced anti-gonadotrophic than androgenic properties in rats. The present study was initiated in rabbits to investigate the potential of D-homo-S to suppress spermatogenesis. D-homo-S in sesame oil was administered at the doses of 0.1 (DI), 3 (D II) or 10 mg (D III) per rabbit each day for 8 weeks. During treatment serum testosterone, sperm concentration and quality of sperm motility decreased, whereas sex drive, semen volume and seminal plasma concentrations of fructose and zinc were not changed in any of the groups. Testicular weight and intratesticular testosterone concentration decreased significantly in groups D II and DIII, while weights of accessory sex glands increased in those groups. Testosterone in the same dose regimen did not suppress sperm count, motility or serum testosterone, however, seminal plasma zinc concentration in group TIII and fructose in group TI increased. Testicular weight and intratesticular testosterone concentration decreased in group TIII only. On the other hand, the weight of the accessory sex glands increased in the same group.
In conclusion, D-homo-S suppresses spermatogenesis and increases accessory sex gland weights at doses, when testosterone is still ineffective. Thus, in rabbits D-homo-S appears to be a more potent androgen than testosterone but a dissociation between antigonadotrophic and androgenic properties could not be observed.     

不同剂量的十一酸睾酮对大鼠生精功能影响

目的 :进一步了解睾丸内睾酮和生精功能的关系。　方法 :大鼠给予不同剂量的十一酸睾酮 (TU)后测定大鼠血清、睾丸间质液和睾网液内睾酮水平 ,以及附睾精子的数量、活力 ,以观察二者之间关系。结果 :大鼠给予不同剂量的十一酸睾酮后 ,睾丸内睾酮水平发生不同的变化 ,随之睾丸内生精功能也发生变化。低剂量十一酸睾酮(8mg/kg)不影响睾丸内睾酮水平 ,也不影响睾丸内的生精过程。附睾精子的数量、活动力与对照组无显著性差异。但给予超生理剂量 (30mg/kg) ,则抑制睾丸内睾酮的产生 ,睾丸内睾酮水平显著下降 ,使精子的发生明显受到抑制。而给予超大剂量的外源性睾酮 (6 2 5mg/kg) ,尽管抑制了睾丸内睾酮的产生 ,但由于补充了大量外源性睾酮 ,使睾丸内睾酮维持在正常水平。精子的发生能维持在正常水平。附睾精子的数量与活动力与对照组无显著性差异。　结论 :进一步论证了睾丸内高浓度的睾酮对维持生精过程起到决定性的作用     

电磁辐射对大鼠睾丸P450scc mRNA表达及睾酮合成的影响和防护

目的:探讨电磁辐射对大鼠睾丸合成睾酮(T)的影响及其机制,评价铜丝网的防护效果。方法:采用Wistar雄性大鼠,随机分为对照组(n=60)、无屏蔽电磁辐照组(n=60)和铜丝网全身屏蔽辐射组(n=60),电磁辐照后分别取3、6、24、72h各时相点各组大鼠15只;采用放射免疫法(RIA)分别测定电磁辐照后3、6、24、72h及对照组血清T含量,反转录聚合酶链反应(RTPCR)测定各组睾丸组织中细胞色素P450胆固醇侧链裂解酶(P450scc)mRNA水平。结果:无屏蔽辐照组辐照后3h血清T含量和P450sccmRNA水平均明显低于对照组(分别较对照组降低83.9%,56.9%;P均<0.01),6h略有回升,但仍明显低于对照组(分别较对照组降低54.8%,27.3%;P均<0.01),24h恢复到正常水平,72h再次出现明显降低(分别较对照组降低60.1%,56.1%;P均<0.01);采用铜丝网全身屏蔽后,血清T和睾丸组织P450sccmRNA表达均未见明显变化。结论:电磁辐射能在转录水平影响睾丸间质细胞P450sccmRNA的表达,从而降低T的合成;铜丝网屏蔽具有较好的防护效果。     

Effect of HCG administration in the gossypol-treated male rats

The effect of gossypol acetic acid (GAA) on the pituitary-Leydig cell axis was studied. Adult male Wistar rats were administered orally 5 mg/kg/day GAA for three weeks, 10 mg/kg/day GAA for three weeks or 20 mg/kg/day GAA for two weeks. Each group was treated for four days with saline or 500 IU human chorionic gonadotropin intraperitoneally injected. None of the rats died. The mean body weight in each group was increased, but the mean body weight gain in the 20 mg/kg group was significantly lower than that in the controls (p less than 0.01). There was no significant change in the weight of testes or epididymis in any group. The serum level of lactate dehydrogenase, follicle stimulating hormone and testosterone was significantly lower in the animals treated with 20 mg/kg/day GAA for two weeks than in the controls (p less than 0.05). No change was seen in other groups. The serum testosterone level after HCG stimulation (HCG 500 IU intraperitoneal injection for 4 days) was significantly lower in animals treated with 20 mg/kg/day GAA for two weeks (p less than 0.01). GAA is suggested to affect the pituitary-Leydig cell axis and directly inhibit Leydig cell function.     

实验性精索静脉曲张对大鼠前列腺组织中睾酮水平及雄激素受体表达的影响

目的探讨实验性精索静脉曲张对大鼠前列腺组织中睾酮水平及雄激素受体表达的影响。方法将36只SD三级雄性大鼠随机分为实验组与对照组,每组18只,实验组建立精索静脉曲张模型,对照组接受假手术,于建模成功后第6、12和18周(各3个阶段,每阶段6只)采用放射免疫法测定血清中睾酮的含量、前列腺组织中睾酮的含量,并进行常规HE染色,观察前列腺组织上皮与基质的形态学变化,同时使用免疫组化法测定前列腺组织中雄激素受体的表达。结果实验组6周组、12周组、18周组血清睾酮、前列腺组织中睾酮水平明显低于同期对照组(P<0.05),且实验组12周组血清睾酮、前列腺组织中睾酮水平明显低于实验组6周组(P<0.05),实验组18周组血清睾酮、前列腺组织中睾酮水平明显低于实验组6周组、实验组12周组(P<0.05)。对照组前列腺组织正常,实验组随着时间的延长前列腺组织损伤越来越严重。实验组6周组前列腺组织中雄激素受体表达较同期对照组明显增强(P<0.05),实验组12周组、实验组18周组前列腺组织中雄激素受体表达较同期对照组与实验组6周组明显减弱(P<0.05)。结论实验性精索静脉曲张可降低大鼠前列腺组织中睾酮水平,导致前列腺组织中雄激素受体表达异常,影响前列腺功能的正常运转,这可能是男性不育或生育能力低下的原因之一。     

Luteinizing hormone secretion by male rat pituitary cells perifused in vitro: effect of experimental left varicocele and orchiectomy

It has been shown previously that experimental left varicocele in the rat, results in a bilateral decrease in intratesticular testosterone. In the present work, pituitary responsiveness to GnRH as a possible mediator of this effect has been examined. Unilateral varicoceles were created in adult rats. A second group of animals underwent a sham operation and a third underwent bilateral orchiectomy. Thirty days after surgery, rats from all three groups were sacrificed and their pituitaries were removed. Dispersed pituitary cells were perifused in Bio-Gel columns with varying concentrations of GnRH. The concentration of LH in the collected eluent was determined by radioimmunoassay. The mean, overall GnRH-stimulated LH immunoreactive secretion rate (ng/min/10(7) cells) by pituitary cells from rats with varicocele (0.062 +/- 0.11) was no different from the overall release from the sham-operated controls (0.051 +/- 0.007). The dose-response curves for GnRH-stimulated release of LH by dispersed pituitary cells in the two groups also were not different. The overall GnRH-stimulated LH release by cells from the orchiectomized rats (0.171 +/- 0.032) was significantly greater than release by cells from the sham-operated and varicocele rats, and the concentration-response curve from the orchiectomy group was significantly elevated over those of the other two groups. These results indicate that GnRH-stimulated immunoreactive LH release is not altered in rats with experimental left varicocele and, thus, is not the source of an endocrinopathy that leads to decreased intratesticular testosterone concentrations in these animals.