Objective    To study the protective effect of catalpol on white matter injury due to chronic cerebral ischemia in rats and its mechanism.     Methods    Twenty-four adult male Wistar rats were randomly divided into sham-operation group

ischemia group

vehicle group and catalpol group

6 rats in each group. A chronic cerebral ischemia model was established by ligating bilateral common carotid arteries. Ischemic rats were treated by intraperitoneal injection with catalpol or vehicle (normal saline) at 5 mg/kg per day for 10 days and killed 30 d after operation. Luxol fast blue (LFB) staining and immunohistochemical staining were used to observe the effects of catalpol on expressions of myelin sheath

myelin basic protein (MBP)

adenomatus polyposis coli [APC (CC-1)]

and glial fibrillary acidity protein (GFAP) in white matter of rats.     Results    The LFB staining was weaker

the expression level of MBP and the number of CC-1 -positive oligodendrocytes (OLs) were lower

and the number of GFAP-positive astrocytes was higher both in ischemia group and in vehicle group (37 259.6±6 626.6 vs 36 554.4±7 865.7

24 016.5±3 794.8 vs  23 923.6±4 605.1

33.0±9.6 vs 32.0±9.8

52.0±7.4 vs 50.0±9.4) than in sham-operation group (P0.01). The damage to white matter was more significantly alleviated in catalpol group than in vehicle group (P0.01). The LFB staining was stronger（86 687.6±6 619.1）

the expression level of MBP （61 604.5±6 319.9）and the number of positice CC- cells（91.±8.4）were higher

and the number of GFAP positive cells was lower (17.0±7.8) in catalpol group than in vehicle group（P0.01）.     Conclusion    Catalpol protects against white matter injury due to chronic cerebral ischemia in rats by inhibiting the proliferation of astrocytes and inflammatory reactions.