Inducible nitric oxide synthase expression in cerebrovascular smooth muscle and neutrophils after traumatic brain injury in immature rats
Inducible nitric oxide synthase expression in cerebrovascular smooth muscle and neutrophils after traumatic brain injury in immature rats
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DOI：
10.1203/00006450-199605000-00007
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发表时间：
1996-05-01
影响因子：
3.6
通讯作者：
Watkins, SC
中科院分区：
文献类型：
--
作者：
Clark, RSB;Kochanek, PM;Watkins, SC
创伤性脑损伤（TBI）后的炎症反应包括细胞因子的产生、白细胞浸润和小胶质细胞激活。诱导型一氧化氮合酶 (iNOS) 会在中枢神经系统外的急性炎症期间和脑缺血模型中产生一氧化氮，因此可能会导致 TBI 后的炎症反应。本研究的目的是定位和定义未成熟大鼠 TBI 后 iNOS 表达的时间过程。将未成熟的 Wistar 大鼠（3.5-4.5 周）麻醉，并对右侧顶叶皮层进行撞击创伤。未受创伤的大鼠用作对照（n = 7）。在2、24、48或168小时（n = 3/组）创伤后大鼠通过灌注固定处死。取出大脑、冷冻、切片、用针对 iNOS 和胶质纤维酸性蛋白（GFAP，星形胶质细胞特异性标记物）的抗体进行免疫染色，并使用荧光检测系统进行成像。在对照大脑中没有检测到 iNOS 表达。 2小时时，在创伤周围区域观察到极少量的脑血管iNOS表达。 24 小时和 48 小时，创伤周围脑血管 INOS 表达明显，似乎仅限于血管平滑肌细胞和浸润白细胞。进一步的双重免疫标记表明表达iNOS的白细胞主要是中性粒细胞。 168 小时时，不再检测到 iNOS 表达。在 GFAP 阳性细胞中未检测到 iNOS。 TBI后脑血管平滑肌细胞和浸润的中性粒细胞中iNOS蛋白的显着表达表明iNOS可能在脑血管障碍和创伤后继发性脑损伤中发挥作用。
The inflammatory response after traumatic brain injury (TBI) includes cytokine production, leukocyte infiltration, and microglial activation. Production of nitric oxide by inducible nitric oxide synthase (iNOS) occurs during acute inflammation outside of the CNS and in models of cerebral ischemia, and therefore may contribute to the inflammatory response after TBI. The purpose of this study was to localize and define the time course of iNOS expression after TBI in the immature rat. Immature Wistar rats (age 3.5-4.5 wk) were anesthetized and subjected to percussive trauma to the right parietal cortex. Nontraumatized rats were used as controls (n = 7). At 2, 24, 48, or 168 h (n = 3/group) posttrauma rats were killed by perfusion fixation. Brains were removed, frozen, sectioned, immunostained with antibodies against iNOS and glial fibrillary acidic protein (GFAP, a marker specific for astrocytes), and imaged using fluorescent detection systems. There was no detectable expression of iNOS in control brains. At 2 h, minimal cerebrovascular iNOS expression was seen in the peritrauma area. At 24 and 48 h, there was marked peritrauma cerebrovascular INOS expression that appeared to be restricted to vascular smooth muscle cells and infiltrated leukocytes. Further dual-immunolabeling showed that the leukocytes expressing iNOS were predominantly neutrophils. At 168 h, iNOS expression was no longer detectable. iNOS was not detectable in GFAP-positive cells. The prominent expression of iNOS protein after TBI in cerebrovascular smooth muscle cells and infiltrated neutrophils suggests that iNOS may play a role in cerebrovascular disturbances and secondary brain injury after trauma.