Relationgship between expression of RGS5 and delayed ischemic neurological deficit after experimental subarachnoid hemorrhage in rats

Abstract

Objective To explore relationship between expression of regulators of G protein signaling 5 (RGS5) and delayed ischemic neurological deficit (DIND) after experimental subarachnoid hemorrhage(SAH) in rats.Methods 90 Sprague-Dawley rats were randomly divided into SAH group (n =42),saline-control group (n =42) and normal control group (n =6).SAH was developed with twice injections of 0.3 ml arterial blood into cisterna magna,and 0.3 ml saline injected for saline-control group.For SAH group and saline-control group,brains were harvested on 1 d,3 d,5 d,7 d,9 d,11 d and 13 d after second injection of blood.6 brains were harvested at each time for each group.Hematoxylin-eosin staining was used to observe pathomorphological changes of brain tissue.Proteins of RGS5 in brain tissue were evaluated by immunohistochemically staining.Expression changes of RGS5 mRNA were identified by insitu hybridization.Same methods were used for normal control group.Results For SAH group,ischemic pathomorphological changes including disordered tissue construction,edema of interstitial substance,degeneration and necrosis of neurons in brain tissue were identified from 3 d to 11 d.For salinecontrol and normal control group,there were no ischemic pathomorphological changes in brains at different time points.Compared with saline-control group and normal,the expression of RGS5 protein and mRNA increased at different time poiuts of SAH group group (P ＜ 0.05),and significantly increased on 5 d than other times (P ＜ 0.05).Conclusions The high expression of RGS5 in the rat brain may be associated with the delayed ischemic neurological deficit after subarachnoid hemorrhage. Key words: Rats ; Delayed ischemic neurological deficit ; Regulators 5 of G protein signaling