Shimakura A, Kamanaka Y, Ikeda Y, Kondo K, Suzuki Y, Umemura K
Department of Pharmacology, Hamamatsu University School of Medicine, 3600 Handa-cho, Hamamatsu, Japan.
Brain Res. 2000 Mar 6;858(1):55-60. doi: 10.1016/s0006-8993(99)02431-2.
It has been reported that activated neutrophils are involved in the development of cerebral damage induced by ischemia. Activated neutrophils release a lot of mediators including toxic oxygen metabolites, elastase and cytokines which damage brain tissue. Therefore, we investigated roles of neutrophil elastase in the development of cerebral damage using an elastase inhibitor, ONO-5046. The rat middle cerebral artery (MCA) was occluded by a thrombus induced by photochemical reaction between green light and the photosensitizer dye, Rose Bengal. Photochemical reaction causes endothelial injury followed by formation of a platelet and fibrin-rich thrombus at the site of the irradiation. Photochemical reaction is routinely used in our laboratory to produce arterial occlusion in experimental animals. Twenty-four hours after the MCA occlusion, the size of cerebral damage was measured by histochemical technique. Water content in the brain was measured and neuronal deficits were examined 24 h after the MCA occlusion. ONO-5046 was administered at various doses as continuous infusion for 24 h, starting just after the MCA occlusion or from 3 h after. ONO-5046 at doses of 10 and 30 mg/kg/h significantly (p<0.05 and p<0.01, respectively) reduced the size of cerebral damage and water content (p<0.05, p<0.01, respectively) in different eight rats. Further, ONO-5046 at a dose of 30 mg/kg/h significantly (p=0.01) improved neuronal deficits. ONO-5046 which was administered starting from 3 h after the MCA occlusion, also reduced the size of cerebral damage. Neutropenia by anti-neutrophil antibody injection significantly (p<0. 01) reduced the size of cerebral damage. Elastase released from activated neutrophils may play a key role in the development of cerebral damage.
据报道，活化的中性粒细胞参与缺血诱导的脑损伤的发展。活化的中性粒细胞释放许多介质，包括有毒的氧代谢产物、弹性蛋白酶和细胞因子，这些物质会损害脑组织。因此，我们使用弹性蛋白酶抑制剂ONO - 5046研究了中性粒细胞弹性蛋白酶在脑损伤发展中的作用。大鼠大脑中动脉（MCA）通过绿光与光敏染料孟加拉玫瑰红之间的光化学反应诱导的血栓进行闭塞。光化学反应导致内皮损伤，随后在照射部位形成富含血小板和纤维蛋白的血栓。在我们实验室中，光化学反应常用于在实验动物中产生动脉闭塞。MCA闭塞24小时后，通过组织化学技术测量脑损伤的大小。测量脑内含水量，并在MCA闭塞24小时后检查神经功能缺损。ONO - 5046以不同剂量连续输注24小时，在MCA闭塞后立即开始或从3小时后开始。在不同的8只大鼠中，剂量为10和30mg/kg/h的ONO - 5046分别显著（p<0.05和p<0.01）减小了脑损伤的大小和含水量（分别为p<0.05，p<0.01）。此外，剂量为30mg/kg/h的ONO - 5046显著（p = 0.01）改善了神经功能缺损。从MCA闭塞3小时后开始给药的ONO - 5046也减小了脑损伤的大小。注射抗中性粒细胞抗体导致的中性粒细胞减少显著（p<0.01）减小了脑损伤的大小。活化的中性粒细胞释放的弹性蛋白酶可能在脑损伤的发展中起关键作用。
