Nitric oxide synthase in the human pituitary gland.
Nitric oxide synthase in the human pituitary gland.
复制标题
DOI：
--
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
R. Lloyd;L. Jin;X. Qian;Shuya Zhang;B. Scheithauer
中科院分区：
文献类型：
--
作者：
R. Lloyd;L. Jin;X. Qian;Shuya Zhang;B. Scheithauer
一氧化氮（NO）是由一氧化氮合酶家族的同工酶产生的，它存在于许多哺乳动物细胞中。组成型NO合酶同工酶产生NO，其通过信号转导机制在包括血管张力和血压的许多功能的调节中起作用，并且诱导型同工酶通过细胞毒性和细胞抑制作用介导免疫机制。为了确定NO是否在垂体前叶细胞功能中发挥作用，我们采用免疫组织化学和原位杂交分析来研究正常和肿瘤人垂体组织中NO合酶的表达。脑内NO合酶定位于分泌期垂体前叶、滤泡星状细胞和垂体后叶。垂体腺瘤与正常垂体相比，脑NO合酶蛋白和mRNA水平较高。内皮型NO合酶也存在于垂体前叶和垂体后叶细胞以及垂体内皮细胞中。用脑NO合酶抗体进行的免疫印迹研究检测到缓慢迁移的约155-kd条带和更快速迁移的约90-kd和约60-kd条带。内皮NO合酶，但不是巨噬细胞NO合酶，也检测到垂体免疫印迹研究，证实了免疫组化观察。这些研究结果表明，NO合酶在正常和肿瘤的人垂体组织中表达，与非肿瘤垂体细胞相比，腺瘤中脑NO合酶蛋白和mRNA的水平增加，并表明NO可能在垂体前叶细胞的激素分泌中起调节作用。
Nitric oxide (NO) is generated by the NO synthase family of isozymes, which is present in many mammalian cells. The constitutive NO synthase isozymes generate NO, which acts via signal transduction mechanisms in the regulation of many functions including vascular tone and blood pressure, and the inducible isozymes mediate immunological mechanisms by cytotoxic and cytostatic effects. To determine whether NO has a role in anterior pituitary cell function, immunohistochemistry and in situ hybridization analyses were used to study NO synthase expression in normal and neoplastic human pituitary tissues. Brain NO synthase was localized in the anterior pituitary in secretory and in folliculo-stellate cells and in the posterior pituitary. Pituitary adenomas had higher levels of brain NO synthase protein and mRNA compared with normal pituitaries. Endothelial NO synthase was also present in anterior and posterior pituitary cells and in endothelial cells of the pituitary. Immunoblotting studies with brain NO synthase antibodies detected a slowly migrating approximately 155-kd band and more rapidly migrating approximately 90-kd and approximately 60-kd bands. Endothelial NO synthase, but not macrophage NO synthase, was also detected in the pituitary by immunoblotting studies, confirming the immunohistochemical observations. These findings indicate that NO synthase is expressed in normal and neoplastic human pituitary tissues with increased levels of brain NO synthase protein and mRNA in adenomas compared with non-neoplastic pituitary cells and suggest that NO may play a regulatory role in hormone secretion in anterior pituitary cells.