Andonian S, Adamali H, Hermo L
Department of Anatomy and Cell Biology, McGill University, Montréal, Québec, Canada.
Mol Reprod Dev. 2001 Apr;58(4):398-410. doi: 10.1002/1098-2795(20010401)58:4<398::AID-MRD7>3.0.CO;2-4.
Endocytosis is an important event in the epididymis as it contributes to a luminal environment conducive for sperm maturation. Principal and clear cells contain numerous lysosomes which degrade many substances internalized by endocytosis from the epididymal lumen. The interior of the lysosomes depends on low pH to activate the release of their enzymes and to activate their acid hydrolases. In the present study, H+K+ATPase was localized by light microscopy in the adult rat epididymis of intact and of orchidectomized animals supplemented with testosterone or not. In normal animals, numerous lysosomes of nonciliated cells of the efferent ducts were intensely reactive for anti-H+K+ATPase antibody. In the initial segment, only a few lysosomes of principal cells were reactive. In the intermediate zone of the epididymis, numerous lysosomes of principal cells were intensely reactive, while the number of intensely reactive lysosomes decreased progressively from the proximal caput to the distal caput with none being seen in the proximal corpus region. In the distal corpus and cauda regions, only a few lysosomes of some principal cells were reactive. In contrast, clear cells of all regions showed intense reactivity. Orchidectomy resulted in the abolishion of H+K+ATPase in lysosomes of principal cells of all regions except the initial segment. However, while clear cells of the caput and corpus regions also became unreactive, those of the cauda region remained as reactive as in controls. Orchidectomized animals supplemented with testosterone maintained a staining pattern similar to controls for both cell types. These observations demonstrate the presence in principal and clear cells of H+K+ ATPase which may have an important role in acidifying the interior of their lysosomes. However, there is a region-specific expression of H+K+ATPase in lysosomes of principal cells, unlike that for clear cells. In addition, H+K+ATPase expression in lysosomes of principal cells depends on testosterone in all regions except the initial segment. However, in the case of clear cells, only those of the caput and the corpus regions are dependent on testosterone, while those of the cauda region appear to be regulated by some other factor.
内吞作用是附睾中的一个重要事件，因为它有助于营造一个有利于精子成熟的管腔环境。主细胞和透明细胞含有大量溶酶体，这些溶酶体可降解从附睾管腔通过内吞作用内化的许多物质。溶酶体内部依赖低pH值来激活其酶的释放并激活其酸性水解酶。在本研究中，通过光学显微镜对完整成年大鼠附睾以及补充或未补充睾酮的去势成年大鼠附睾中的H⁺K⁺ATP酶进行了定位。在正常动物中，输出小管非纤毛细胞的大量溶酶体对抗H⁺K⁺ATP酶抗体呈强反应性。在起始段，主细胞中只有少数溶酶体有反应。在附睾的中间区，主细胞的大量溶酶体呈强反应性，而强反应性溶酶体的数量从近端头部到远端头部逐渐减少，在近端体部区域未见。在远端体部和尾部区域，只有一些主细胞的少数溶酶体有反应。相比之下，所有区域的透明细胞都显示出强反应性。去势导致除起始段外所有区域主细胞溶酶体中的H⁺K⁺ATP酶消失。然而，虽然头部和体部区域的透明细胞也变得无反应，但尾部区域的透明细胞仍与对照组一样有反应。补充睾酮的去势动物两种细胞类型的染色模式均维持与对照组相似。这些观察结果表明主细胞和透明细胞中存在H⁺K⁺ATP酶，其可能在酸化其溶酶体内部方面发挥重要作用。然而，主细胞溶酶体中H⁺K⁺ATP酶存在区域特异性表达，与透明细胞不同。此外，除起始段外，所有区域主细胞溶酶体中H⁺K⁺ATP酶的表达都依赖睾酮。然而，就透明细胞而言，只有头部和体部区域的透明细胞依赖睾酮，而尾部区域的透明细胞似乎受其他一些因素调节。
