超极化激活环核苷酸门控离子通道2在内脏高敏感性大鼠视上核的表达及作用  

Expression and effect of supraoptic HCN2 on visceral hypersensitive rats

作　　者：毛广通 苗蓓 王德广 MAO Guangtong;MIAO Bei;WANG Deguang(Department of Human Anatomy,School of Basic Medical Sciences,Xuzhou Medical University,Xuzhou 221004,China)

机构地区：[1]徐州医科大学基础医学院人体解剖学教研室,江苏徐州221004 [2]徐州医科大学附属医院消化科,江苏徐州221006 [3]徐州医科大学影像学院,江苏徐州221004

出　　处：《实用医学杂志》2021年第4期434-440,共7页The Journal of Practical Medicine

基　　金：国家自然科学基金(编号:81872847)。

摘　　要：目的研究超极化激活环核苷酸门控阳离子通道2(HCN2)在慢性内脏高敏感性(CVH)大鼠下丘脑视上核的表达及作用。方法新生雄性Sprague⁃Dawley大鼠随机分为假手术(Sham)、结直肠扩张(CRD)、溶剂(Vehicle)、ZD72881 ng、ZD728810 ng和ZD7288100 ng组,每组6只。新生大鼠CRD法制备CVH模型。大鼠8周龄时,采用腹壁撤退反射(AWR)评分、内脏痛阈和腹外斜肌放电肌电图(EMG)等方法评估HCN2通道抑制剂ZD7288视上核立体定位注射对大鼠内脏感知的影响,之后处死大鼠。应用HE法对大鼠结肠进行病理染色,免疫组织化学、免疫荧光和Western blot检测视上核HCN2、c⁃Fos的表达。结果光镜下,大鼠结肠组织HE染色未见显著病理性改变。与Sham组相比,CRD组大鼠视上核HCN2表达显著上调(P<0.05);c⁃Fos阳性细胞显著增多(P<0.05);HCN2和c⁃Fos共表达细胞显著增多(P<0.05)。ZD7288视上核立体定位注射可剂量依赖性地升高CVH大鼠的AWR评分和EMG曲线下面积,降低内脏痛阈(P<0.05)。结论下丘脑视上核通过上调HCN2通道蛋白参与抑制大鼠的内脏高敏感性。Objective To investigate the expression and impact of the supraoptic hyperpolarization⁃activated cyclic nucleotide gated 2(HCN2)on chronic visceral hypersensitive(CVH)rats.Methods Neonatal male Sprague⁃Dawley rats were randomly divided into sham operated(Sham)group,colorectal distention(CRD)group,Vehicle group,ZD72881 ng group,ZD728810 ng group and ZD7288100 ng group.Neonatal CRD was enrolled to establish the rat models of CVH.ZD7288,the inhibitor HCN2,was stereotactically injected in supraoptic nuclei(SON)at the 8th postnatal week,and the effects of ZD7288 on visceral sensation were assessed via procedures of abdominal withdrawal reflex(AWR)score,visceral pain threshold and the electromyograph(EMG)of external oblique muscle discharge.All rats were sacrificed by 4%⁃paraformaldehyde perfusion or decapitation,and the brains and colons(between left curvature of colon and the pelvis)were collected for further detections.The hematoxylin⁃eosin(HE)staining of colon tissue was performed to avoid subjects with organic conditions.The supraoptic expression of HCN2 and c⁃Fos were detected by immunohistochemistry,immunofluorescence and Western blot.Results Morphological detection showed that there were no obvious morphological changes in rats with the use of colonic HE staining.Compared with Sham group,the expression of supraoptic HCN2 was significantly upregulated in CRD group by immunohistochemistry and Western Blot(P<0.05);the c⁃Fos positive cells in SON were significantly increased in CRD group by immunohistochemistry(P<0.05);the number of HCN2 and c⁃Fos co⁃labeled cells in SON were significantly increased by immunofluorescent(P<0.05).Behavioral and electrophysiological tests showed that the stereotactic injection of ZD7288 in SON dose⁃dependently increased the AWR scores and AUC,and decreased the visceral pain threshold compared with the Vehicle group(P<0.05).Conclusions SON inhibits the chronic visceral hypersensitivity via the upregulation of HCN2 in rats.

关 键 词：内脏高敏感性 HCN2 结直肠扩张 

分 类 号：R574.4[医药卫生—消化系统]