低频超声微泡增强紫杉醇诱导三阴性乳腺癌细胞自噬的作用及机制

目的 探讨低频超声微泡增强紫杉醇诱导三阴性乳腺癌细胞自噬的作用及机制。方法 将MDA-MB-468细胞分为对照组(不进行处理)、紫杉醇组(6μg/ml紫杉醇)、低频超声组(低频超声+6μg/ml紫杉醇)和低频超声微泡组(低频超声+6μg/ml紫杉醇+微泡),检测各组MDA-MB-468细胞增殖情况,凋亡情况,自噬情况,Bcl-2、Bax、Beclin1、LC3Ⅰ、LC3Ⅱ蛋白表达情况。结果 与0μg/ml相比,1、3、6、12、24μg/ml紫杉醇处理下MDA-MB-468细胞增殖抑制率均升高(P 0. 05)。与对照组相比,紫杉醇组MDA-MB-468细胞增殖抑制率、凋亡率、细胞中Bax、Beclin1、LC3Ⅱ蛋白表达水平升高(P 0. 05),细胞中绿色点状物明显增多,细胞中Bcl-2、LC3Ⅰ蛋白表达水平降低(P 0. 05);与紫杉醇组相比,低频超声组MDA-MB-468细胞增殖抑制率、凋亡率、细胞中Bax、Beclin1、LC3Ⅱ蛋白表达水平升高(P 0. 05),细胞中绿色点状物明显增多,细胞中Bcl-2、LC3Ⅰ蛋白表达水平降低(P 0. 05);与低频超声组相比,低频超声微泡组MDA-MB-468细胞增殖抑制率、凋亡率、细胞中Bax、Beclin1、LC3Ⅱ蛋白表达水平升高(P 0. 05),细胞中绿色点状物明显增多,Bcl-2、LC3Ⅰ蛋白表达水平降低(P 0. 05)。结论 低频超声微泡可通过上调Bax、Beclin1、LC3Ⅱ蛋白表达及下调Bcl-2、LC3Ⅰ蛋白表达增强紫杉醇诱导三阴性乳腺癌细胞的凋亡、自噬反应。     

金钱草总黄酮对草酸钙结晶肾损伤的作用机制

目的:探讨金钱草总黄酮对一水合草酸钙(COM)诱导肾小管上皮细胞凋亡所致肾损伤的影响及其机制。方法:应用不同浓度COM处理肾小管上皮细胞(HK-2)建立体外泌尿系结石细胞模型,将肾小管上皮细胞分为对照组、金钱草总黄酮处理组(TF组)、P38丝裂原活化蛋白激酶(p_38/MAPK)抑制组(SB组)、COM处理组(COM组)、COM和金钱草总黄酮处理组(CTF组)、COM和p_38/MAPK抑制组(CSB组)6组,WST-1法检测细胞存活率,Western blot检测人肾损伤分子(KIM-1)、(p-p)_38、p_38、自噬相关蛋白LC3-Ⅱ的表达,流式细胞术检测不同处理组的细胞凋亡数。结果:COM浓度为0.5、1、2、5 mmol/L时,细胞存活率分别为(85.02±5.50)%、(70.27±3.78)%、(58.09±3.23)%、(42.56±4.13)%,较对照组(99.83±3.65)%降低(P0.05)。在COM处理的肾小管上皮细胞中,随着时间的增加,KIM-1、(p-p)_38及LC3-Ⅱ表达增加。COM可诱导HK-2细胞过度自噬和凋亡,CSB组细胞凋亡率较COM组降低[(7.91±0.70)%vs(29.90±1.07)%,P0.05]。CSB组LC3-Ⅱ表达较COM组降低[(0.52±0.04)vs(1.17±0.04),P0.05]。CTF组(p-p)_38蛋白水平较COM组降低[(0.66±0.06)vs(1.01±0.06),P0.05]。随着金钱草总黄酮浓度的增加,HK-2细胞存活率也逐渐增加。CTF组细胞凋亡率较COM组降低[(10.54±1.07)%vs(29.90±1.07)%,P0.05]。CTF组LC3-Ⅱ表达较COM组降低[(0.82±0.10)vs(1.17±0.04),P0.05]。结论:金钱草总黄酮可通过阻断p_38/MAPK通路抑制肾小管上皮细胞的过度自噬和凋亡,减少肾小管上皮细胞的损伤,从而抑制泌尿系结石的形成。     

通过共培养观察被马兜铃酸活化后的肾小管上皮细胞对肾间质成纤维细胞的作用

目的通过共培养观察被马兜铃酸钠盐(AA-Na)活化后的肾小管上皮细胞株(HK-2)对肾间质成纤维细胞(hRIFs)的作用。方法用AA-Na刺激HK-2,16h后用此活化的HK-2与hRIFs共培养(培养液中加或不加抗TGF-β1抗体),48h后检测hRIFs细胞层中Ⅰ型胶原(ColⅠ)含量。结果(1)AA-Na(20μg/ml)对HK-2无刺激增殖、转分化及细胞毒作用。(2)用此浓度AA-Na刺激HK-216h,能使HK-2分泌TGF-β1显著增加(P<0.05)。(3)用此活化后的HK-2与hRIFs共培养48h,能使后者合成ColⅠ显著增多(P<0.05);而抗TGF-β1抗体(1.0或2.0μg/ml)能部分抑制此反应(P<0.05)。结论被AA-Na刺激活化的HK-2能分泌TGF-β1促进hRIFs合成ColⅠ。     

阿帕替尼治疗晚期胃癌中介导肾脏损伤的作用及机制研究

目的:阿帕替尼在治疗晚期胃癌期间会引起患者肾脏损伤,但这其中的机制尚不清楚。因此本研究旨在探讨阿帕替尼在治疗癌症期间介导肾脏损伤的可能机制。方法:选取2017年6月—2019年6月我院收治的100例给予阿帕替尼化疗的晚期胃癌患者,评价化疗前后患者尿糖和尿β_2微球蛋白(β_2-Microglobulin,β_2-M)的变化。用0μmol/L、5μmol/L、10μmol/L、20μmol/L、40μmol/L、80μmol/L阿帕替尼处理肾小管上皮细胞(HK-2),CCK-8检测细胞存活,western blot检测自噬相关蛋白,使用自噬诱导剂雷帕霉素诱导自噬,CCK-8检测自噬对HK-2细胞的影响,使用自噬抑制剂3-MA联合阿帕替尼处理HK-2细胞,检测抑制自噬对细胞的影响。结果:与化疗前比较,化疗后尿糖和尿β_2-M显著增加(P0.05)。使用不同浓度(0μmol/L、5μmol/L、10μmol/L、20μmol/L、40μmol/L、80μmol/L)的阿帕替尼处理肾小管上皮HK-2细胞,阿帕替尼浓度≥20μmol/L的细胞毒性显著增加(P0.05),HK-2细胞存活显著降低(P0.05)。使用80μmol/L阿帕替尼处理HK-2细胞6 h、12 h、24 h、48 h后,HK-2细胞中自噬标志蛋白LC3B-Ⅱ在12 h、24 h、48 h后表达显著增加(P0.001)。使用自噬诱导剂雷帕霉素(10μmol/L)处理HK-2细胞6 h、12 h、24 h、48 h后,HK-2细胞在12 h、24 h、48 h后显著降低(P0.05)。使用阿帕替尼处理HK-2细胞48 h后,HK-2细胞存活显著降低(P0.001),使用自噬抑制剂3-MA处理,细胞存活显著增加(P0.001)。结论:阿帕替尼治疗胃癌期间会激活肾脏细胞自噬而增加肾脏损伤。     

结缔组织生长因子介导血管紧张素Ⅱ诱导的人肾近端小管细胞肥大机制

目的探讨结缔组织生长因子(CTGF)介导血管紧张素(Ang)Ⅱ致肾小管上皮细胞肥大的可能作用机制。方法用AngⅡ刺激体外培养的人肾近端小管上皮细胞株(HK-2),以流式细胞仪观察抗CTGF抗体(0.5μg/ml)对AngⅡ(10-7mol/L)诱导的细胞周期分布改变的影响。用RT-PCR观察不同浓度AngⅡ(0、10-9、10-7、10-5mol/L)刺激细胞48h,和AngⅡ(10-7mol/L)在不同时间点(0、24、48、72h)时HK-2细胞p27kip1mRNA表达情况;同时观察抗CTGF抗体(0.5μg/ml)对AngⅡ(10-7mol/L)诱导p27kip1mRNA表达变化的影响。用免疫细胞化学法观察抗CTGF抗体(0.5μg/ml)对AngⅡ(10-7mol/L)诱导的细胞p27kip1蛋白表达的影响。结果AngⅡ使G0～G1期细胞百分比明显增加(P<0.01),抗CTGF抗体可显著抑制AngⅡ诱导的细胞周期阻滞(P<0.05)。AngⅡ呈时间和浓度依赖性刺激p27kip1mRNA表达上调(P均<0.05),抗CTGF抗体可以显著抑制AngⅡ诱导的p27kip1mRNA表达的增加(P<0.05),免疫细胞化学显示AngⅡ可显著增加肾小管上皮细胞p27kip1蛋白表达,此作用可被抗CTGF抗体抑制。结论CTGF在AngⅡ诱导HK2细胞肥大中可能发挥重要的作用,其机制可能与抑制细胞表达p27kip1,并逆转细胞增殖周期阻滞有关。     

地塞米松对马兜铃酸诱导的肾小管上皮细胞凋亡的影响

目的：探讨地塞米松（DXT）对马兜铃酸（aristolochic acid,AA）诱导的人近端肾小管上皮细胞凋亡的影响及其可能机制。方法：应用不同浓度DXT处理经AA诱导的近端肾小管上皮细胞株（HK-2细胞）48h;应用Hoechst33258染色法和流式细胞技术检测HK-2细胞凋亡百分率;应用RT-PCR法测细胞Caspase-3 mRNA的表达;应用分光光度法测细胞Caspase-3酶活性。结果：40μg/mlAA可显著促进HK-2细胞凋亡,DXT可显著降低AA诱导的HK-2细胞凋亡百分率,并呈剂量依赖趋势;各组细胞Caspase-3mRNA表达水平无统计学差异;40μg/mlAA可显著升高HK-2细胞Caspase-3酶活性;而100MDXT组细胞Caspase-3酶活性较单纯40μg/mlAA刺激显著降低,而其他浓度DXT组细胞Caspase-3活性与单纯AA比较无统计学差异。结论：DXT对AA所致HK-2细胞凋亡有一定的保护作用,其机制可能是抑制细胞凋亡过程中Capease-3酶的激活。     

血管内皮生长因子C减轻顺铂所致的肾小管上皮细胞毒性损伤

目的观察血管内皮生长因子C(vascular endothelial growth factor-C,VEGF-C)在顺铂诱导的人肾小管上皮细胞(HK-2)毒性损伤模型中mRNA的表达变化,探究VEGF-C对顺铂诱导人肾小管上皮细胞毒性损伤的作用和介导其作用的相关分子机制。方法体外培养人近端肾小管上皮细胞系,用不同浓度的顺铂刺激HK-2细胞24 h后,利用实时荧光定量RT-PCR法检测HK-2细胞VEGF-C mRNA的表达变化,CCK8法检测不同浓度的顺铂对HK-2细胞存活率的影响。分别用0、50、100、200 ng/rr的人重组VEGF-C因子预培养HK-2细胞4 h后,再加入50μmol/L的顺铂和一定浓度的VEGF-C继续培养HK-2细胞24 h,利用CCK8法检测细胞存活率的变化,明确VEGF-C对顺铂诱导的肾小管上皮细胞毒性损伤的作用。用不同浓度的VEGF-C刺激HK-2细胞30 min后,Western blot方法检测细胞p-Akt、Akt、p-Erk、Erk、p-p38及p38蛋白水平的变化。结果不同浓度的顺铂刺激HK-2细胞后细胞VEGF-C mRNA水平的表达呈现先上升后下降的趋势。顺铂能引起HK-2细胞存活率减低,并呈现浓度依赖性。而外源性加入VEGF-C能减轻顺铂所导致的HK-2细胞毒性损伤,提高细胞的存活率,并且VEGF-C浓度为200 ng/ml时对HK-2细胞的保护作用最明显。不同浓度的VEGF-C刺激HK-2细胞30 min,随着VEGF-C浓度的增加,HK-2细胞p-Akt、pErk的表达也逐渐增加,而Akt、Erk、p-p38及p38表达不变。结论 VEGF-C能减轻顺铂诱导的肾小管上皮细胞毒性损伤,提高细胞的存活率,其作用机制可能与激活细胞内PI3K/Akt及MAPK/Erk信号通路有关。     

低密度脂蛋白和氧化低密度脂蛋白诱导人肾小管上皮细胞转分化的通路研究

目的探讨低密度脂蛋白（LDL）和氧化（OX）LDL是否可诱导人肾小管上皮细胞转分化及其可能机制。方法体外培养的第2代肾小管上皮细胞随机分为（1）阴性对照组；（2）LDL（50mg／ml）组；（3）oxLDL（50mg／ml）组；（4）LDL（50mg／m1）＋PD98059（5μmol／L）组；（5）oxLDL（50mg／ml）＋PD98059（5μmol／L）组。应用形态学、免疫荧光、Western印迹观察LDL和oxLDL刺激小管细胞角蛋白（cytokerafin）、E-钙粘糖蛋白（cadhefin）、α-SMA和波形蛋白（vimenfin）表达的改变、Ⅰ型胶原产生的改变，及其与ERK1／2MAPK通路活化的关系。结果OXLDL较LDL有更强的致小管上皮细胞转分化的作用，与对照组相比。细胞中上皮细胞标记cytokeratin和E-cadherin表达减少，间充质细胞标记α-SMA和vimentin明显增加，Ⅰ型胶原产生增多（P〈0．05）。LDL和oxLDL刺激组细胞中ERK1／2MAPK和GSK-3β磷酸化活化较对照组明显增强（P〈0．05）；β-catenin发生细胞核内转移。MAPK抑制剂PD98059可抑制GSK-3β的磷酸活化，并几乎完全阻断oxLDL诱导的肾小管上皮细胞转分化，但对LDL诱导的小管上皮细胞转分化只有部分阻断作用。结论本研究首次在体外观察到（1）oxLDL可诱导肾小管细胞上皮细胞转分化和Ⅰ型胶原的产生，作用明显强于LDL；（2）ERK1／2MAPK、GSK-3β和β-catenin组成一条信号通路调节LDL和oxLDL诱导的小管上皮细胞转分化。     

基质细胞衍生因子-1对小鼠关节软骨细胞自噬水平的影响

目的：通过研究基质细胞衍生因子-1（stromal derived factor?1, SDF?1）对小鼠关节软骨细胞自噬的影响,探讨SDF?1在骨性关节炎中的作用及机制。方法分离并体外培养小鼠关节软骨细胞,分别予以0、1、10、100、1000μg/L浓度的五组重组SDF?1蛋白干预24 h。运用RT?PCR检测各组细胞的微管相关蛋白1轻链3（microtubule associated protein 1 light chain 3, LC3）和UNC?51样激酶复合物1（uncoordinated?51 like kinase 1, ULK1）mRNA表达情况,运用Western Blot方法检测LC3?Ⅱ、LC3?Ⅰ、ULK1及泛素连接蛋白62（ubiquitin?binding protein p62, p62）蛋白表达水平,通过透射电镜观察自噬溶酶体。结果 RT?PCR结果显示10、100、1000μg/L浓度条件下LC3、ULK1的mRNA水平明显高于对照组,且差异具有统计学意义（P＜0.05）。Western Blot结果显示1、10、100、1000μg/L的各组细胞的LC3?Ⅱ/LC3?Ⅰ比值、ULK?1表达水平较对照组升高,p62蛋白表达水平较对照组明显降低,差异具有统计学意义（P＜0.05）。透射电镜结果显示经SDF?1干预后,自噬溶酶体较对照组增多,差异具有统计学意义（P＜0.05）。结论 SDF?1可诱导小鼠关节软骨细胞自噬的发生,SDF?1可能通过调节软骨细胞自噬水平参与了骨性关节炎的进展。     

汉防己甲素对马兜铃酸A致肾小管上皮细胞Bcl-2/Bax的表达及细胞内钙离子的影响

目的：观察汉防己甲素（Tet）对马兜铃酸AⅠ（AAⅠ）诱导的肾小管上皮细胞Bcl-2/Bax表达及细胞内钙离子影响。方法：将人近端肾小管上皮细胞株（HK-2）,随机分为正常组、模型组、汉防己甲素高、中、低浓度组和泼尼松龙组共6组。除正常组外,余5组用AAⅠ（10μg/ml）刺激体外培养的HK-2;Tet高、中、低浓度组和泼尼松龙组分别加入500ng/ml、100ng/ml、20ng/ml的Tet及500ng/ml的泼尼松龙。细胞培养36h后,观察其形态;用RT-PCR法检测各组Bcl-2、BaxmRNA表达水平;用Western-blotting法检测各组Bcl-2、Bax蛋白表达水平;激光共聚焦显微镜检测各组细胞内钙离子浓度变化。结果：经AAⅠ刺激后,模型组的细胞形态、排列、数目与正常组比较均有明显的变化,表现为HK-2明显拉长梭形变,细胞间排列明显松散,细胞数目明显减少,Tet及泼尼松龙干预组细胞的改变明显轻于模型组,尤其是Tet各组;与模型组相比,Tet高、中浓度组及泼尼松龙组均能显著升高Bcl-2mRNA表达（1.20±0.18、1.03±0.14和1.01±0.13比0.59±0.04,均P〈0.05）,Bcl-2蛋白表达（1.00±0.01、0.86±0.07和0.93±0.07比0.28±0.19,均P〈0.05）;降低BaxmRNA表达（0.74±0.19、0.88±0.11和0.82±0.03比1.15±0.10,均P〈0.05）和Bax蛋白表达（0.80±0.07、0.81±0.03和0.82±0.03比0.97±0.05,均P〈0.05）;Tet各组呈现浓度相关性,即高浓度Tet组疗效好于中、低浓度Tet组,且P〈0.05。激光共聚焦显微镜检测显示：细胞内平均钙离子荧光强度与模型组对照,Tet高、中浓度组及泼尼松龙显著降低,差异有统计学意义（12.301±0.858、20.159±0.725和11.983±0.460比33.082±1.006,均P〈0.05）。结论：Tet对AAⅠ诱导的肾小管上皮细胞有保护作用,其机制可能与调控Bcl-2、Bax的mRNA和蛋白,阻滞细胞内钙离子浓度的升高有关。     

2015年乳腺癌辅助化疗进展

【摘要】〓乳腺癌是危害我国女性健康的头号杀手,尽管近年来辅助化疗的研究进展突飞猛进,但临床中仍有不少问题未能明确,如辅助化疗的合适人群、化疗的开始时间、蒽环及紫杉类的地位和用法、强化维持治疗的作用、疗效及预后的生物标志物等。本文结合乳腺癌辅助化疗在临床上的常见问题和2015年各大乳腺癌会议阐述乳腺癌辅助化疗的最新进展。     

Alterations in T-Cell Subset Frequency in Peripheral Blood in Obesity

Background: Obesity affects the regulation of immune and inflammatory responses. This study characterizes differences in peripheral blood lymphocyte phenotype in obese humans. Methods: Frequencies of lymphocyte subsets among peripheral blood mononuclear cells were compared between 10 obese (BMI ≥35) and 10 lean subjects, as determined by antibodies directed against cluster differentiation (CD) markers. Results: Obese patients demonstrated an increased frequency of CD3+CD4+ T-cells (mean difference 12%, P=0.004), a decreased frequency of CD3+CD8+ T-cells (mean difference 9.4%, P=0.016) and an increased frequency of CD3+CD8+CD95+ T-cells (mean difference 13.3%, P=0.032). No other differences among T-cell or monocyte subsets were noted. Conclusions: Obesity is associated with alterations in frequencies of peripheral CD4+ and CD8+ T-cells and aberrations in the expression of CD95 among CD8+ T-cells. These data suggest both CD4+ and CD8+ T-cell compartments, as well as the regulation of CD95 expression on CD8+ T-cells, as targets for further study into obesity's effects on the immune system.     

西宁地区烧伤病人动脉血气分析观察

对高海拔地区的27例烧伤病人动脉血气变化进行了分析和观察。结果证明:无论是存活病人还是死亡病人伤后均存在有低氧血症问题。并且在死亡病人和烧伤合并吸入性损伤病人其低氧血症的发生早于单纯烧伤病人。提示:吸入性损伤病人应立即行气管切开术以保障氧气供给,单纯烧伤病人可常规吸氧以维持正常血 PaO_2,ARDS 均发生在合并吸入性损伤的病人,高频喷射通气技术对纠正低氧血症有一定效果。     

Controversies in Fistula in Ano

Managing a complex fistula in ano can be a daunting task for most surgeons; largely due to the two major dreaded complications—recurrence & fecal incontinence. It is important to understand the anatomy of the anal sphincters & the aetiopathological process of the disease to provide better patient care. There are quite a few controversies associated with fistula in ano & its management, which compound the difficulty in treating fistula in ano. This article attempts to clear some of those major controversies.     

β-半乳糖苷酶在体内外成骨细胞中的表达

目的 研究β—半乳糖苷酶(β—gal)在成骨细胞中的表达状况，为阐明MorquioB综合征的发病机制提供依据。方法 裸鼠各器官和骨组织标本行X-gal染色检测。抽取羊和人骨髓行骨髓基质细胞(BMSCs)培养，分为4组：I：Adv-hBMP-2转染组；Ⅱ：Adv—β—gal转染组；Ⅲ：未转染组；Ⅳ：地塞米松诱导组。分别行X-gal染色和RT-PCR检测β—gal的表达。结果 裸鼠骺板两侧、骨膜内面及松质骨的成骨细胞和破骨细胞可见多量β—gal的表达。未转染BMSCs组有少量β—gal的表达，其他3组细胞的β—gal表达增高。结论成骨细胞和破骨细胞可表达多量β—gal，该两种细胞的β—gal缺乏可能是MorquioB综合征骨骼异常的直接原因。     

Smoking-Attributable mortality in Spain in 2016

IntroductionSmoking-attributable mortality (SAM) is a valuable indicator that can be used to characterize the course and health burden of the smoking epidemic. The aim of this paper was to estimate SAM in Spain in 2016 in the population aged 35 and over, using the best available evidence.MethodsA smoking prevalence-dependent analysis based on the estimation of population-attributable fractions was performed. Smoking prevalence (never, former, and current smokers) was calculated from a combination of the Spanish Health Survey (2016) and the European Health Survey (2014); the relative risk of death among current and former smokers was taken from the follow-up of various cohorts; and mortality rates were obtained from National Center for Statistics data. SAM estimates are presented globally, and by sex, age groups, and major disease categories: cancer, cardiometabolic diseases and respiratory diseases.ResultsIn 2016, 56,124 deaths were attributed to tobacco consumption, 84% in men (47,000), and 50% in the population aged over 74 (27,795). Overall, 50% of SAM was due to cancer (28,281), 65% of which was lung cancer. One in 4 attributable deaths (13,849) occurred before the age of 65.ConclusionsOne in 7 deaths in Spain in 2016 were attributable to smoking. This estimation of SAM clearly highlights the great impact of smoking on mortality in Spain, mainly due to lung cancer and chronic obstructive pulmonary disease.     

MicroRNAs in hepatic pathophysiology in diabetes

MicroRNAs(miRNAs or miRs) are small approximately 22 nucleotide RNA species that are believed to regulate diverse metabolic and physiological processes.In the recent past,several reports have surfaced that demonstrate the role of miRNAs in various biological processes and numerous disease states.For a disease as complex as diabetes,the emergence of miRNAs as key regulators leading to the disease phenotype has added a novel dimension to the area of diabetes research.On the other hand,the liver,a metabolic hub,contributes in a major way towards maintaining normal glucose levels in the body as it can both stimulate and inhibit hepatic glucose output.This equilibrium is frequently disturbed in diabetes and hence,the liver assumes special significance considering the correlation between altered hepatic physiology and diabetes.While the understanding of the mechanisms behind this altered hepatic behavior is not yet completely understood,recent reports on the status and role of miRNAs in the diabetic liver have further added to the complexities of the knowledge of hepatic pathophysiology in diabetes.Here,we bring together the various miRNAs that play a role in the altered hepatic behavior during diabetes.     

Fluid-phase transcytosis in the primate epididymis in vitro and in vivo

Ligated tubules from the corpus epididymidis of men and monkeys were incubated in medium containing horseradish peroxidase (HRP) as a marker for fluid-phase endocytosis. HRP was localized by light and electron microscopy after 0, 15, 30 and 60 min of incubation. Movement between the cells was prevented by tight junctions, but bypass of this barrier was apparently achieved by an intracellular vesicular mechanism leading to a time-dependent appearance of HRP in the lumen. Uptake of HRP into basal cells and capture by the lysosomal apparatus of principal cells were also observed. HRP-filled vesicles also appeared in the basal, mid and apical cytoplasm of epithelial cells in the caput 1 h after injection of the tracer into the epididymal circulation of the monkey, suggesting that this pathway also operates in vivo.