邻苯二甲酸单乙基己基酯对原代培养大鼠睾丸Leydig细胞睾酮合成的影响

目的:探讨邻苯二甲酸二乙基己基酯(DEHP)的代谢产物邻苯二甲酸单乙基己基酯(MEHP)对SD大鼠体外培养睾丸间质细胞(Leydigcells)睾酮合成的影响。方法:建立SD大鼠睾丸Leydig细胞体外原代培养模型,MEHP染毒剂量组分为对照(0μmol/L)、62.5、125、250、500、1000μmol/L,通过噻唑蓝(MTT)法观察线粒体活性,放射免疫法测定睾酮浓度,RTPCR法测定Leydig细胞类固醇合成急性调节蛋白(StAR)mRNA表达。结果:MEHP染毒24h后,Leydig细胞线粒体活性在250μmol/L时显著上升,1000μmol/L时显著下降,与对照组比较,差异均有显著性(P<0.01)。基础状态及人绒毛膜促性腺激素(hCG)刺激状态下,Leydig细胞睾酮合成水平均呈上升趋势,与对照组相比,250、500μmol/L剂量组差异均有显著性(P<0.01)。Leydig细胞StARmRNA的表达在62.5、125、250μmol/L时与对照组相比均未见有显著性改变,在500、1000μmol/L时显著下降(P<0.01)。结论:MEHP直接影响原代培养Leydig细胞线粒体活性及睾酮合成,胆固醇跨膜转运的调节因子StAR与MEHP引起睾酮合成上升的原因可能无关。     

养精胶囊对Leydig细胞增殖、凋亡和睾酮合成的影响

目的 探讨养精胶囊对Leydig细胞增殖、凋亡和睾酮合成功能的影响.方法 在Leydig中加入不同剂量养精胶囊提取液24h、48h、72h后,用MTT法检测各组的吸光值;用流式细胞仪分析Leydig细胞在加入不同剂量养精胶囊提取液48h后的细胞凋亡率;用化学发光法测定Leydig细胞在加入不同剂量养精胶囊提取液24h后合成T的变化.结果 Leydig细胞在加入中、高剂量养精胶囊提取液48h和72h后,细胞增殖明显加快,其吸光值与空白组相比差异有统计学意义(P＜0.05);在Leydig细胞中加入中、高剂量养精胶囊提取液48h后,细胞凋亡率和死细胞率明显降低,活细胞率明显提高,与空白组相比差异有统计学意义(P＜0.01);在Leydig细胞中加入中剂量养精胶囊提取液24h后,睾酮合成明显增加,与空白组相比差异有统计学意义(P＜0.01).结论 养精胶囊可能通过影响Leydig细胞的增殖、凋亡,增强其分泌功能等多途径,而提高睾酮合成的功能,并与时间和剂量有关.这也证实了益肾填精法能直接作用于Leydig细胞而影响睾酮的合成.     

DEHP体外对大鼠睾丸间质细胞凋亡Caspase通路的影响

目的:通过对原代培养的大鼠睾丸间质细胞进行邻苯二甲酸二乙基己酯(di-2-ethylhexyl phthalate,DEHP)染毒,探讨DEHP体外对大鼠睾丸间质细胞凋亡通路Caspase-3和Caspase-9表达以及细胞凋亡的影响。方法:体外分离和原代培养大鼠睾丸间质细胞,用不同浓度的DEHP(10、50、100 nmol/L)染毒24 h。荧光定量PCR法检测间质细胞Caspase-3和Caspase-9 mRNA表达,Western印迹检测间质细胞Caspase-3和Caspase-9蛋白表达,流式细胞术检测间质细胞凋亡率。结果:与对照组相比,DEHP各组睾丸间质细胞Caspase-3 mRNA(1.69±0.38 vs3.82±0.39、6.91±0.40、15.47±0.40)和蛋白(0.18±0.09 vs 0.32±0.10、0.61±0.08、0.89±0.09)表达显著增加(P均<0.05),Caspase-9 mRNA(2.24±0.41 vs 5.16±0.43、9.61±0.45、19.22±0.43)和蛋白(0.26±0.07 vs0.40±0.08、0.68±0.09、0.96±0.08)表达也显著增加(P均<0.05),细胞凋亡率(4.36±1.11 vs 7.52±1.09、12.72±1.10、24.59±1.11)也显著增加(P均<0.05),呈浓度依赖关系。结论:DEHP可通过激活细胞凋亡Caspase通路而诱导大鼠睾丸间质细胞凋亡,进而影响间质细胞功能。     

金匮肾气丸对雄激素部分缺乏大鼠血清睾酮及StAR蛋白mRNA表达的影响

目的 探讨金匮肾气丸对雄激素部分缺乏模型大鼠血清睾酮及StAR蛋白mRNA表达的影响.方法 将40只SD大鼠采用腹腔注射环磷酰胺(20mg/kg·d-1)复制模型后,随机分为4组,即模型组、金匮肾气丸高、中、低剂量组,每组各10只,分别采用蒸馏水及金匮肾气丸水溶液高、中、低剂量灌胃,治疗28d后,观察血清睾酮及睾丸StAR蛋白mRNA表达.结果 与模型组(98.33±8.36)ng/dl比较,金匮肾气丸高剂量组(301.17:1:46.90)ng/dl、中剂量组(21.5.46±26.73)ng/dl血清睾酮显著性升高,差异有统计学意义(P＜0.05,P＜0.01);金匮.肾气丸高剂量组(11.08±1.45)、中剂量(10.47±1.26)、低剂量组(7.30±1.08)之间睾丸StAR蛋白mRNA表达水平分别与模型组(4.87±0.95)比较差异有统计学意义(P＜0.01).结论 金匮肾气丸可提高雄激素部分缺乏大鼠血清睾酮水平,其机制可能是通过提高睾丸StAR蛋白mRNA表达水平实现.     

邻苯二甲酸二乙基己酯及代谢产物MEHP对幼鼠睾丸组织TGF-β1表达和端粒酶活性的影响

目的:观察邻苯二甲酸二乙基己酯(DEHP)及代谢产物邻苯二酸-单-2-乙基己酯(MEHP)对幼鼠睾丸组织转化生长因子-β1(TGF-β1)表达和端粒酶活性的影响,探讨DEHP和MEHP损害生精功能可能的机制。方法:生后2周龄的Wistar雄性幼鼠96只,随机分8组,每组12只。随机选择1组行生理盐水[0.9%NS0.2 ml/(kg.d),喂养3周]灌胃,作为正常对照组(NC组);再选1组行环磷酰胺[CTX 100 mg/(kg.d),喂养1周]灌胃,作为阳性对照组(PC组);余各组分别用DEHP、MEHP按低剂量[100 mg/(kg.d),喂养3周]、中剂量[200 mg/(kg.d),喂养2周]、高剂量[300 mg/(kg.d),喂养1周]灌胃制作动物模型。观察不同时期、不同剂量下睾丸组织精子形态变化,光镜下计数精子头部及畸形率;应用免疫组化SABC法及RT-PCR法检查睾丸组织TGF-β1的表达,并测定面密度;ELISA法检查睾丸组织中端粒酶活性。结果:①睾丸组织内精子形态变化:用药组精子数量减少,出现精子断头、无钩、双尾等畸形精子;在光镜下精子计数,与NC组比较,用药各组精子头部显著减少(P<0.05),畸形率增加(P<0.05),但高剂量短时间用药组与低剂量长时间用药组比较,差异无统计学意义(P>0.05)。②睾丸组织TGF-β1的表达变化:NC组低表达,DEHP及代谢产物MEHP染毒各组生精细胞内表达增多,PC组大量表达,阳性细胞呈黄褐色,主要分布于胞膜及胞质。NC组面密度为0.156 0±0.003 5、TGF-β1mRNA为1.51±0.20,PC组面密度为0.534 0±0.003 1、TGF-β1 mRNA为8.43±1.75;用药的DEHP组面密度均值为0.289 0±0.003 6、TGF-β1 mRNA为3.83±1.57,MEHP组面密度均值为0.284 0±0.003 1、TGF-β1 mRNA为3.51±1.41,用药各组与NC组、PC组比较差异有统计学意义(P<0.01),但高剂量短时间用药组与低剂量长时间用药组比较,差异无统计学意义(P>0.05);③睾丸组织中端粒酶活性:与NC组比较,用药各组睾丸组织中端粒酶活性下降(P<0.05),高剂量短时间用药组与低剂量长时间用药组比较,差异无统计学意义(P>0.05)。结论:DEHP及代谢产物MEHP对幼鼠生精功能有明显损害,其损害机制可能与DEHP及代谢产物MEHP诱导睾丸组织TGF-β1的表达水平升高、端粒酶活性降低有关。     

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。     

胰岛素和睾酮对Ishikawa细胞HOXAIO基因表达的影响

目的观察胰岛素（INS）和睾酮（T）对子宫内膜腺癌细胞HOXA10基因表达的影响。方法免疫细胞化学检测HOXA10蛋白在Ishikawa细胞定位表达;体外培养Ishikawa细胞,予不同浓度INS（90、60、30、3、0．3U／L）或T（10^-3、10^-4、10^-5、10^-5、10^-7mol／L）刺激Ishikawa细胞48h,MTT法检测INS、T对Ishikawa细胞生长的作用;最后分别以30U／LINS和10^-5mol／LT刺激Ishikawa细胞48h,逆转录聚合酶链反应（RT-PCR）方法测定INS和T对Ishikawa细胞HOXA10mRNA表达的影响。结果（1）HOXA10蛋白定位表达于Ishikawa细胞的细胞浆内。（2）不同浓度的INS均可促进Ishikawa细胞的生长,随着浓度的增加作用越强,INS浓度达60、90U／L时,细胞生长状况与浓度为30U／L相似。不同浓度的T均可抑制Ishikawa细胞的生长,随浓度增加抑制作用越明显,浓度达10^-4、10^-3mol／L时,细胞生长抑制状况与浓度为10^-3mol／L相似。（3）RT-PCR检测结果显示INS组和T组Ishikawa细胞中HOXA10mRNA表达均较对照组减弱（P〈0．01或P〈0．05）。结论不同浓度INS和T均可影响Ishikawa细胞生长,高浓度的INS和T降低细胞上HOXA10mRNA的表达。     

酪氨酸、米非司酮和睾酮对大鼠颗粒细胞凋亡的影响

大多数哺乳类动物的卵巢卵泡在排卵前闭锁，研究表明其发生机制是细胞凋亡。本实验观察了卵巢调控因子酪氨酸、米非司酮和睾酮对大鼠卵巢颗粒细胞凋亡的影响。结果：米非司酮和睾酮促进凋亡，造成ＤＮＡ的片段化反应；而酪氨酸的作用则相反。与对照组相比，米非司酮和睾酮组血清雌二醇含量下降而孕酮含量升高；酪氨酸组血清雌二醇水平升高而孕酮水平下降。米非司酮和睾酮增加闭锁卵泡数，酪氨酸作用则相反。     

胰岛素和睾酮对Ishikawa细胞葡萄糖转运蛋白4表达的影响

目的探讨胰岛素(INS)和睾酮(T)对多囊卵巢综合征(PCOS)子宫内膜腺上皮细胞生长的影响和葡萄糖转运蛋白4(GLUT4)表达的调节机制。方法体外培养Ishikawa细胞,予不同浓度INS(90、60、30、3、0.3 U/L)或T(10-3、10-4、10-5、10-6、10-7mmol/ml)刺激Ishikawa细胞48 h,MTT法检测INS、T对Ishikawa细胞生长的作用;免疫细胞化学检测GLUT4蛋白在Ishikawa细胞定位表达;分别以30 U/L INS和10-5mmol/ml T刺激Ishikawa细胞24和48 h,逆转录聚合酶链反应(RT-PCR)方法测定INS和T对Ishikawa细胞GLUT4 mRNA表达的影响。结果(1)不同浓度的INS均可促进Ishikawa细胞的生长,随着INS浓度的增加,INS促进Ishikawa细胞生长作用越强,INS浓度自0.3~30 U/L时,Ishikawa细胞生长依次加强,与对照组相比均有显著性差异(P<0.01)。INS浓度达60、90 U/L时,细胞生长状况与INS浓度为30 U/L相似。不同浓度的T均可抑制Ishikawa细胞的生长,随着T浓度的增加,T抑制Ishikawa细胞生长作用越明显。T浓度自10-7、10-6、10-5mmol/ml,Ishikawa细胞生长依次减弱,与对照组相比均有显著性差异(P<0.01,P<0.05),T浓度达10-4、10-3mmol/ml时,细胞生长抑制状况与T浓度10-5mg/ml相似。(2)GLUT4蛋白,定位表达于Ishikawa细胞的细胞浆内。(3)Ishikawa细胞中GLUT4 mRNA表达,在INS组和T组均较对照组减弱(P<0.01,P<0.05),INS组比T组减弱更明显(P<0.05),且INS和T作用24和48 h GLUT4 mRNA表达无显著性差异(P>0.05)。结论不同浓度INS和T均可影响Ishikawa细胞生长,并降低GLUT4 mRNA的表达,推测PCOS高胰岛素、高雄激素血症的病理生理特性有可能影响子宫内膜的代谢过程,与子宫内膜的病变相关。     

Effects of local heating of the testis on testicular blood flow and testosterone secretion in the rat

Exposure of one or both testes of rats to heating at 43 degrees C for 30 min resulted in a significant reduction in blood flow per testis, as measured using microspheres. The effects on the testes of unilateral and bilateral heating were similar, although the changes in FSH levels in peripheral blood were in general less marked after unilateral heating. Testicular blood flow fell, along with testicular weight, beginning at 2-4 days and reaching minimum values 14-21 days after heating. Both blood flow per testis and testicular weight were beginning to recover 35 days post-heating and blood flow per testis was normal by 56 days following heat treatment, although testicular weight was still slightly reduced at that time. Heating one or both testes to 42 degrees C produced similar but smaller responses 21 days later, whereas temperatures of 41 degrees C or lower were without effect on the parameters measured, except for some rises in serum LH and FSH. With slight reductions in blood flow, there were corresponding increases in testicular venous testosterone concentration so that testosterone secretion was unaffected. Further reductions in blood flow at 14 and 21 days after heating to 43 degrees C were not fully compensated by an increase in the concentration of testosterone in testicular venous blood, with the result that testosterone secretion fell.     

Feeding hydroalcoholic extract powder of Lepidium meyenii (maca) increases serum testosterone concentration and enhances steroidogenic ability of Leydig cells in male rats

Although Lepidium meyenii (maca), a plant growing in Peru's central Andes, has been traditionally used for enhancing fertility and reproductive performance in domestic animals and human beings, effects of maca on reproductive organs are still unclear. This study examined whether feeding the hydroalcoholic extract powder of maca for 6 weeks affects weight of the reproductive organs, serum concentrations of testosterone and luteinising hormone (LH), number and cytoplasmic area of immunohistochemically stained Leydig cells, and steroidogenesis of cultured Leydig cells in 8‐week‐old male rats. Feeding the extract powder increased weight of seminal vesicles, serum testosterone level and cytoplasmic area of Leydig cells when compared with controls. Weight of prostate gland, serum LH concentration and number of Leydig cells were not affected by the maca treatment. The testosterone production by Leydig cells significantly increased when cultured with 22R‐hydroxycholesterol or pregnenolone and tended to increase when cultured with hCG by feeding the extract powder. The results show that feeding the hydroalcoholic extract powder of maca for 6 weeks increases serum testosterone concentration associated with seminal vesicle stimulation in male rats, and this increase in testosterone level may be related to the enhanced ability of testosterone production by Leydig cells especially in the metabolic process following cholesterol.     

Effects of a chronic treatment with testosterone on the morphology of the interstitial cells of the rat testis: an ultrastructural stereologic study

The suppressive effects of chronic testosterone administration on the rat testicular interstitial cells (Leydig cells) were investigated by stereological methods. The volume of cells, nuclei, mitochondrial compartment and smooth endoplasmic reticulum (SER), as well as the surface area of SER and mitochondrial cristae decreased significantly as a function of the duration of treatment. The decrease in the SER volume accounted for about 75–80% of that in the cell volume. These findings lend support to the view that SER is the subcellular organelle more responsive to the changes in the functional activity of rat Leydig cells.     

Serum testosterone response to single injection of hCG ovine-LH and LHRH in male rats

A biphasic pattern of testosterone secretion in response to a single injection of 100 IU hCG has been observed in the rat. Serum testosterone increased from basal levels of 8.7 pL 3.1 ng/ml (mean pL SEM) to 23.0 pL 1.4 ng/ml within 2 h of hCG-stimulation and returned to control levels by 2 days. A second, delayed, but significant increase in serum testosterone occurred, reaching a peak of 24.6 pL 4.0 ng/ml at 3 days and declining to basal values at 5 days. To study this response further, lower doses of hCG were tried. Administration of 10 IU hCG produced a single peak of testosterone, which did not occur until 24 h. Differences in the serum testosterone response were related to the concentration of hCG measured in the serum after injection, as injection of 1 IU, which failed to increase serum hCG levels above detection, was also inadequate to increase serum testosterone. The response after stimulatin with 500 μg ovine-LH or 0.1–10.0 μg LHRH was also evaluated. Injection of 500 μg ovine-LH produced a significant rise in serum testosterone reaching a peak at 2 h of 25.2 pL 2.6 ng/ml and subsequently declining over the next 48 h to control levels where it remained for 5 days. Stimulation with doses of 0.1–10.0 μg LHRH produced rapid and short increases in serum LH concentration which induced peaks of testosterone up to 48.8 pL 14.1 ng/ml 1 h post injection. No secondary peak of testosterone followed. Failure of ovine-LH and LHRH to produce a second testosterone peak suggests that this response may be due to a re-stimulation of the Leydig cell by elevated levels of hCG which persist until the fourth day after injection.     

内皮素对大鼠睾丸间质细胞睾酮生成的影响

本研究采用大鼠睾丸间质细胞体外培养的技术 ,观察了内皮素 1对离体间质细胞睾酮分泌的影响。研究发现 ,10 -9mol/L的ET 1可显著抑制间质细胞睾酮的基础分泌 (P <0 .0 5 ) ,并且ET 1对人绒毛膜促性腺激素 (hCG)刺激睾丸间质细胞睾酮分泌也有抑制作用 ,其有效抑制浓度为 10 -10 mol/L(P <0 .0 5 )。本实验结果提示 ,ET 1呈剂量依赖性抑制睾丸间质细胞睾酮的基础分泌和hCG诱导的分泌 ,ET 1可能为睾丸内的一种局部调节多肽     

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.     

Morphometric analysis of the components of the neonatal and the adult rat testis interstitium

Leydig cells in the foetal rat testis are still present at birth and it has been hypothesized that they commence to degenerate immediately after birth, based on the decrease in their volume density (v/v%) with age. In this study the interstitium of the rat testis was studied quantitatively at 1, 5, 10, 15, 20 and 90 days after birth: the latter are considered to be adults. The absolute volumes of connective tissue cells and blood vessels increased with age. The absolute volumes of macrophages and lymphatic spaces were greater at 90 days than at any other age. The absolute volume of foetal Leydig cells per testis was unchanged from 1 to 15 days, despite a decrease in the % volume occupied per testis. The number of foetal Leydig cells per testis did not decline from days 1-20 although on day 20 an average foetal Leydig cell was smaller in volume than at earlier ages (days 1-15). Adult Leydig cells were recognized at day 10 and their absolute volume and number per testis increased from 15 to 90 days. Adult Leydig cells were similar in morphology to foetal Leydig cells at 20 days except for a reduced volume of cytoplasmic lipid.     

c-jun对离体睾丸间质细胞睾酮分泌作用的机理研究

目的本研究拟通过c-jun反义寡脱氧核苷酸(ASODNs)观察c-jun在调节hCG促进睾丸间质细胞(leydigcells,LC)睾酮分泌中的作用机制。方法用c-junASODNs拮抗c-jun,再加用cAMP观察其对睾酮分泌的影响,用放射免疫方法检测睾酮水平。结果hCG可刺激LC睾酮分泌,是LC功能研究的有用模型。c-junASODNs呈剂量依赖性地抑制hCG诱导下的离体LC的睾酮分泌(P<0.01)。加用cAMP后睾酮分泌增加。结论c-jun促进hCG诱导的大鼠LC的睾酮分泌,c-jun表达可能与cAMP相关。     

Is testosterone essential for maintenance of normal morphology in immature rat Leydig cells?

Selective deprivation of gonadotrophins in prepubertal rats by administration of a GnRH antagonist (Ac-D2Nal¹, D4ClPhe², DTrp³, DArg⁶, DA1a¹⁰-GnRH; GnRH code: 103–289–10, National Institutes of Health, USA) for 3 weeks, initiated at 20–22 days of age, induced morphological changes in the Leydig cells, including thickening and indentation of the nuclear margin, pyknosis and elongation of the nuclei. Mean nuclear diameter was reduced to 22% of that in the controls. Under the electron microscope the cells exhibited reduced volume of the nucleus and cytoplasm and the plasma membrane was irregular. This abnormal appearance of the Leydig cells improved marginally in 20–30% of the Leydig cells and their mean nuclear diameter increased to 39% of the control level after FSH supplementation (20 μg ovine FSH/day). Normal morphological integrity of the Leydig cells consisting of round or oval nuclei, a smooth nuclear and cellular margin and the original mean nuclear diameter was restored completely when testosterone (30 μg/day) was administered to GnRH antagonist-treated rats, with or without simultaneous administration of FSH; in these rats testosterone levels in blood were also restored to normal. These findings indicate that testosterone may be important for the maintenance of normal Leydig cell morphology in the rat.     

Effects of local heating of the testes on the concentration of testosterone in jugular and testicular venous blood of rats and on testosterone production in vitro

Heating both testes of rats to between 39 degrees C and 41 degrees C for 30 min was apparently without effect 21 days later, but heating to between 41.5 degrees C and 43 degrees C for 30 min resulted in a significant drop in testis weight accompanied by significant rises in the serum levels of LH and FSH. There were no changes in serum testosterone concentration in the peripheral circulation although there were increases in the concentration in testicular venous blood. The ability of the heated testis to secrete testosterone in vivo in response to maximal stimulation by hCG was reduced, as judged by testosterone levels in peripheral blood, while there was a supranormal increase in testosterone levels in testicular venous blood. Maximally stimulated testosterone production in vitro by the heated testis was supranormal whereas the basal production of testosterone per testis was not different from control values. Therefore, it appears that the testosterone produced by Leydig cells from heated testes may not be secreted as effectively as in normal testes.