ABSTRACT
Objective To investigate the effect of splenectomy on infarct volume in middle cerebral artery occlusion in focal cerebral ischemia rats and its possible mechanisms.Methods Eighteen male Sprague-Dawley rats were randomly divided into spleneetomy,sham splenectomy,and control groups (n =6 in each group).A model of middle cerebral artery occlusion (MCAO) was induced by the intraluminal suture method 2 weeks after spleneetomy.The rats were decapitated and their brains were removed after 24 hours.The infarct volume was measured with Nissl body staining The number of macrophages in ischemic cortex was detected with immunofluorescence staining Results The infarct volume in the splenectomy group (34.93％ + 3.23％ )was significantly smaller than that in the sham splenectomy group (74.33％ + 2.36％ ; q =39.399,P ＜ 0.001 ) and the control group (77.30％ + 2.62％ ; q =42.369,P ＜ 0.001 ).However,there was no significant difference between the sham splenectomy group and the control group (q =2.970,P =0.082).The number of macrophages of the ischemic cortex in the splenectomy group (3.4 ± 1.07/per high power field) was significantly less than that in the sham splenectomy group (20.7±4.37/per high power field; q =17.300,P＜0.001) and the control group (18.87 ±4.17/per high power field; q =15.467,P ＜0.001).However,there was no significant difference between the sham splenectomy group and the control goup (q =1.833,P =0.384).Conclusions Splenectomy may reduce the infarct volume by reducing the number of macrophages in ischemic corticalregion.