Yingfeng Wan1,2, Feng Gao1,3, Fenghui Ye1, Weiming Yang1, Ya Hua1, Richard F Keep4, Guohua Xi5. 1. Department of Neurosurgery, University of Michigan, R5018 Biomedical Science Research Building, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA. 2. Department of Neurosurgery, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China. 3. Department of Neurology, 2nd Affiliated Hospital, Zhejiang University, Hangzhou, China. 4. Department of Neurosurgery, University of Michigan, R5018 Biomedical Science Research Building, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA. rkeep@umich.edu. 5. Department of Neurosurgery, University of Michigan, R5018 Biomedical Science Research Building, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA. guohuaxi@umich.edu.
Abstract
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.
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.
Authors: Chaoyi Bian; Yingfeng Wan; Sravanthi Koduri; Ya Hua; Richard F Keep; Guohua Xi Journal: Transl Stroke Res Date: 2022-05-11 Impact factor: 6.829
Authors: Jingwei Zhang; Kang Peng; Fenghui Ye; Sravanthi Koduri; Ya Hua; Richard F Keep; Guohua Xi Journal: Transl Stroke Res Date: 2021-06-02 Impact factor: 6.829