Futrell N, Garcia J H, Peterson E, Millikan C
Department of Neurology, Henry Ford Health Sciences Center, Detroit, Mich. 48202.
Stroke. 1991 Dec;22(12):1582-91. doi: 10.1161/01.str.22.12.1582.
Although stroke is a disorder associated with aging, experimental studies of stroke are conducted in young adult (2-4-month-old) animals (rat life span, 27-29 months). To determine whether histopathologic changes caused by cerebral infarction would be altered in aged animals, we produced embolic cerebral infarction in 17 aged (23-24-month-old) and 16 young (2-4-month-old) rats.
The right common carotid artery was irradiated with a laser (632 nm, 200 mW/cm2, 15-20 minutes) after the intravenous injection of the photosensitizing dye Photofrin II (12.5 mg/kg). This produces a nonocclusive platelet thrombus that spontaneously embolizes to the brain. Animals were killed 4 days later.
Analysis was done on 142 infarcts, 68 in aged rats and 74 in young rats. Hypercellularity, with infiltration of macrophages, was more common within small infarcts (less than 1 mm) in young than in aged rats (p = 0.002), and hypertrophy of astroglial fibers surrounding the infarcts was more prominent in young rats. Larger infarcts (greater than or equal to 1 mm) were often hypocellular, with a trend toward more macrophages in the periphery of the infarcts in young than in old animals (p = 0.170).
The infiltration of macrophages into cerebral infarcts and the hypertrophy of astroglial fibrils surrounding these infarcts are reduced in the aged rat. These age-related differences emphasize the importance of using appropriately aged animals in experimental models of stroke.
尽管中风是一种与衰老相关的疾病，但中风的实验研究却是在年轻成年（2 - 4个月大）动物（大鼠寿命为27 - 29个月）身上进行的。为了确定脑梗死引起的组织病理学变化在老年动物中是否会改变，我们在17只老年（23 - 24个月大）和16只年轻（2 - 4个月大）大鼠中制造了栓塞性脑梗死。
在静脉注射光敏染料卟吩姆钠（12.5毫克/千克）后，用激光（632纳米，200毫瓦/平方厘米，15 - 20分钟）照射右侧颈总动脉。这会产生一个非闭塞性血小板血栓，该血栓会自发栓塞到脑部。4天后处死动物。
对142个梗死灶进行了分析，其中老年大鼠有68个，年轻大鼠有74个。年轻大鼠小梗死灶（小于1毫米）内的细胞增多及巨噬细胞浸润比老年大鼠更常见（p = 0.002），并且年轻大鼠梗死灶周围的星形胶质纤维肥大更明显。较大梗死灶（大于或等于1毫米）通常细胞较少，年轻动物梗死灶周边的巨噬细胞数量比老年动物有增多趋势（p = 0.170）。
老年大鼠脑梗死灶内巨噬细胞的浸润以及梗死灶周围星形胶质纤维的肥大减少。这些与年龄相关的差异强调了在中风实验模型中使用年龄合适的动物的重要性。
