Instituto de Investigaciones Biomédicas, Facultad de Medicina, Universidad de Buenos Aires. Paraguay 2155, Piso 10, C1121 ABG, Buenos Aires, Argentina.
Immunobiology. 2012 Aug;217(8):778-87. doi: 10.1016/j.imbio.2012.04.007. Epub 2012 May 17.
Male reproductive tract infection and inflammation are important aetiological factors of infertility. Experimental Autoimmune Orchitis (EAO) is a model of chronic inflammation useful to study mechanisms of inflammatory reactions leading to testicular impairment. EAO is characterised by interstitial cell infiltrate of lymphomonocytes, producers of pro-inflammatory cytokines involved in germ cell apoptosis. Nitric oxide (NO), a free radical promoting immune cell activation and apoptosis, is synthesised by conversion of l-arginine to l-citrulline catalysed by NO synthase (NOS). The NOS isoforms are: constitutively endothelial (e) and neuronal (n) NOS and inducible (i) NOS.
Although the NO-NOS system was found to be up-regulated by pro-inflammatory mediators in immune and non immune testicular cells, data on its regulation in chronic inflammatory states is lacking.
EAO was induced in rats by active immunisation with spermatic antigens and adjuvants; control (C) rats were injected with adjuvants. Untreated normal (N) rats were also studied. We demonstrated that iNOS, eNOS and nNOS was mainly expressed by interstitial cells in N and C rats and that in EAO NOS was up-regulated and also expressed by tubular cells. Constitutive and inducible NOS content (Western blot) as well as NO production and activity increased in the testis of rats with EAO. iNOS content and activity were selectively up-regulated in the testis of rats with orchitis. Flow cytometric analysis of NOS isoforms in testicular macrophages (M) showed that the percentage of ED1(+)ED2(-) and ED1(+)ED2(+) M subsets, expressing constitutive and iNOS isoforms was significantly higher in EAO, but no change in the percentage of ED1(-)ED2(+) resident M was observed compared to C rats. M from EAO rats also released more NO than C and N rats.
In testis of rats with EAO, NO-NOS system was up-regulated and both testicular M and cells from seminiferous tubules contributed to NO increase. NO over production in orchitis was generated mainly by increased iNOS content and activity.
男性生殖系统感染和炎症是导致不育的重要病因。实验性自身免疫性睾丸炎（EAO）是一种慢性炎症模型，可用于研究导致睾丸损伤的炎症反应机制。EAO 的特征是间质细胞中有淋巴细胞浸润，这些细胞产生参与生精细胞凋亡的促炎细胞因子。一氧化氮（NO）是一种促进免疫细胞激活和凋亡的自由基，可由左旋精氨酸转化为左旋瓜氨酸，由一氧化氮合酶（NOS）催化合成。NOS 同工酶有：组成型内皮（e）和神经元（n）NOS 和诱导型（i）NOS。
尽管在免疫和非免疫性睾丸细胞中发现了由促炎介质上调的 NO-NOS 系统，但缺乏关于其在慢性炎症状态下的调节的数据。
通过用精子抗原和佐剂主动免疫诱导大鼠 EAO；对照（C）大鼠注射佐剂。还研究了未经处理的正常（N）大鼠。我们证明，iNOS、eNOS 和 nNOS 主要由 N 和 C 大鼠的间质细胞表达，而在 EAO 中 NOS 上调并由管状细胞表达。EAO 大鼠睾丸中组成型和诱导型 NOS 含量（Western blot）以及 NO 产生和活性增加。在睾丸炎大鼠的睾丸中，iNOS 含量和活性被选择性地上调。睾丸巨噬细胞（M）中 NOS 同工型的流式细胞术分析表明，在 EAO 中，表达组成型和 iNOS 同工型的 ED1(+)ED2(-)和 ED1(+)ED2(+)M 亚群的百分比显著升高，但与 C 大鼠相比，ED1(-)ED2(+)驻留 M 的百分比没有变化。与 C 和 N 大鼠相比，来自 EAO 大鼠的 M 释放的 NO 也更多。
在 EAO 大鼠的睾丸中，NO-NOS 系统被上调，睾丸 M 和生精小管细胞均有助于 NO 增加。睾丸炎中 NO 的过度产生主要是由 iNOS 含量和活性的增加引起的。
