Department of Neurosurgery, University of Michigan, R5018 Biomedical Science Research Building, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA.
Department of Neurosurgery, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China.
Fluids Barriers CNS. 2020 Feb 28;17(1):8. doi: 10.1186/s12987-020-0169-y.
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.
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.
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.
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.
脑积水是脑室出血（IVH）后常见且严重的并发症，会影响预后。虽然老龄化会影响 IVH 患者脑积水的发生，但这一现象及其潜在机制尚未得到充分关注。因此，本研究在大鼠模型中探讨了老龄化对 IVH 后脑积水的影响。
年轻（3 月龄）和老年（18 月龄）雄性 Fischer 344 大鼠分别向侧脑室注射 200μl 自体血或生理盐水。采用磁共振成像（MRI）评估脑室容积，通过组织学染色和 Western blot 定量评估室管膜损伤、血红素加氧酶-1（HO-1）和脉络丛表皮细胞激活。此外，还研究了向年轻和老年大鼠脑室内注射铁对脑积水的影响。
向年轻和老年大鼠侧脑室内注射自体血均可诱发脑积水，但 IVH 后第 3 天至第 14 天，老年大鼠的脑室容积明显大于年轻大鼠。此外，IVH 后第 1 天，老年大鼠的室管膜损伤和室周 HO-1 上调更为明显。IVH 后第 14 天，老年大鼠的脉络丛表皮细胞也更多。此外，IVH 后 23%（3/13）的老年大鼠出现了有组织的血肿，而年轻大鼠则没有。与 IVH 引起的血肿相似，向老年大鼠脑室内注射铁也会导致更多的表皮细胞激活和更严重的脑积水。
与年轻大鼠相比，IVH 会引起老年大鼠更严重的脑积水。增强的室管膜损伤、表皮细胞激活和铁过载可能导致老年动物脑积水加重。
