Background Hydrocephalus is a common and major complication that affects outcome after intraventricular hemorrhage (IVH). While aging impacts the occurrence of hydrocephalus in patients with IVH this and the underlying mechanisms have received little attention. The present investigation, therefore, studied the impact of aging on hydrocephalus after IVH in a rat model. Methods Young and aged (3 and 18 months old, respectively) male Fischer 344 rats had an intraventricular injection of 200 μl autologous blood or saline. Ventricular volume was estimated using magnetic resonance imaging (MRI), while ventricular wall damage, heme oxygenase-1 (HO-1) and epiplexus cell activation were quantified by histological staining and Western blot. Additionally, the impact of intraventricular iron injection was examined in young and aged rats. Results Intraventricular injection of autologous blood induced hydrocephalus in both young and aged rats but ventricular volumes were larger in aged rats compared to young rats from day 3 to day 14 followed IVH. In addition, ventricular wall damage and periventricular HO-1 upregulation were greater in aged versus young rats on day 1 after IVH. Aged rats also had more choroid plexus epiplexus cells on day 14 after IVH. Additionally, organized hematomas were observed in 23% (3/13) of aged rats but not in young rats after IVH. Organized hematomas in aged rats showed larger T2* lesions on MRI compared to rats with non-organized hematomas. Similar to the effects of IVH, intraventricular injection of iron resulted in more epiplexus cells activation and more severe hydrocephalus in aged compared to young rats. Conclusions IVH causes more severe hydrocephalus in aged compared to young rats. Enhanced ventricular wall damage, epiplexus cell activation and iron overload may contribute to this aggravated hydrocephalus development in aged animals.

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衰老对脑室内出血后脑积水的影响

背景脑积水是一种常见的主要并发症，会影响脑室内出血 (IVH) 后的预后。虽然衰老会影响 IVH 患者脑积水的发生，但其潜在机制很少受到关注。因此，本研究在大鼠模型中研究了衰老对 IVH 后脑积水的影响。方法 年轻和年老（分别为 3 个月和 18 个月大）雄性 Fischer 344 大鼠脑室内注射 200 μl 自体血或生理盐水。使用磁共振成像 (MRI) 估计心室容积，而通过组织学染色和蛋白质印迹量化心室壁损伤、血红素加氧酶-1 (HO-1) 和外丛细胞活化。此外，在年轻和老年大鼠中检查了脑室内铁注射的影响。结果 脑室内注射自体血在年轻和老年大鼠中均引起脑积水，但与 IVH 后第 3 天至第 14 天的年轻大鼠相比，老年大鼠的脑室容积更大。此外，在 IVH 后第 1 天，老年大鼠与年轻大鼠的心室壁损伤和脑室周围 HO-1 上调更大。老年大鼠在 IVH 后第 14 天也有更多的脉络丛上丛细胞。此外，在 23% (3/13) 的老年大鼠中观察到有组织的血肿，但在 IVH 后的年轻大鼠中未观察到。与具有无组织血肿的大鼠相比，老年大鼠的有组织血肿在 MRI 上显示出更大的 T2* 病变。与 IVH 的影响类似，与年轻大鼠相比，脑室内注射铁导致老年大鼠更多的外神经丛细胞活化和更严重的脑积水。结论 与年轻大鼠相比，IVH 在老年大鼠中引起更严重的脑积水。增强的心室壁损伤、外神经丛细胞活化和铁过载可能导致老年动物脑积水加重。