Activation changes of oligodendrocyte progenitor cells during chronic cerebral hypoperfusion in young and aged rats

Objective To observe the reactive changes of oligodendrocyte progenitor cells(OPC)in chronic cerebral hypoperfusion in rats and the effect of ageing on this process.Methods The changes of morphology number and distribution of OPC were detected by using neuron-glia antigen 2(NG2)immunohistochemistry at 2 weeks,1 month,and 3 months after cerebral hypoperfusion in the young and aged rat models.Results The rat chronic cerebral hypoperfusion models existed obvious reactive proliferation in NG2 immunohistochemistry stained OPC positive cells,as compared with the normal!young and aged control groups,the differences were significant(P0.01).The cells distributed in cortex,subcortex,hippocampus,callosum,etc.,particularly in subcortex near the area of white matter and the hippocampus dentate gyrus,and most obviously at 2 weeks and 1 month.However,the intensity and numbers of NG2 immunohistochemistry stained OPC positive cells after cerebral hypoperfusion in the young rats were still higher than those in the aged rats(P0.05).Conclusion OPC in the brains of rats proliferate and activate obviously during the process of chronic cerebral hypoperfusion,their reactivity is affected by age factor,and may become a compensatory adaptation or repair mechanism after chronic cerebral hypoperfusion.