Effect of dl-3-n-butylphthalide (NBP) on life span and neurological deficit in SHRsp rats

Effects of NBP on liability of stroke, life span and neurological deficits following stroke were studied in stroke prone spontaneously hypertensive rats (SHRsp). The SHRsp rat was kept on 1% NaCl solution as drinking water and was fed 15 g soft food containing 0.6-0.8 g NaCl per day. Total NaCl intake for one rat was 1.1-1.3 g per day. After the onset of stroke, tap water and normal food was given instead of that containing NaCl. The neurological deficits were evaluated by a specially designed scoring system. These symptoms were divided into 4 degrees (1-4). Grade 1. stress (mild). Grade 2. forelimb or head twitch or with stress (severe). Grade 3. hemiparalysis, body inclined or disabled. Grade 4. paralysis, tremor or convulsion. Blood pressure, heart rate and body weight were measured once every 2 weeks. The weights of heart, brain and kidneys were also measured. The results show that NBP pre-treatment at the dose of 100 mg.kg-1.d-1 po delayed the onset of stroke. So, like nimodipine, NBP showed a stroke preventive action in SHRsp rats. In addition, treatment with NBP 100 mg.kg-1.d-1 po after the onset of stroke, the life span was prolonged and the score of neurological deficit decreased significantly. Because high blood pressure can not be lowered by NBP treatment, therefore, the protective effect against stroke can not be explained by the effect of hypotension. No change was found in BP, HR and the organ weight. The results indicate that NBP is expected to be useful in the treatment of stroke.