Chen, SH

Cheung, RTF

HKU Scholars Hub

Title In vivo study of neuropeptide Y in focal cerebral ischaemiaAuthor(s) Chen, SH; Cheung, RTFCitation The 5th Medical Research Conference, Hong Kong, China,January 2000, v. 22 n. Supp 2, p. 53Issued Date 2000URL http://hdl.handle.net/10722/46813Rights Creative Commons: Attribution 3.0 Hong Kong LicenseS-N-4CLONING AND EXPRESSION OF MP13, A NEW FACTOR RELATED TO GTP REGULATION# # t AZhehui Feng , Shu Leong Ho , Jau-Shyong Hong , Qiping Qi, and Guoying Bing*#Division of Neurology, University Department of Medicine, University of Hong Kong, Queen Mary Hospital,Pokfulam Road, Hong Kong; ' Neuropharmacology Section, Laboratory of Pharmacology and Chemistry,NIEHS/NIH, Research Triangle Park, NC 27709; ^Institute of Environmental Health Monitoring, ChineseAcademy of Preventive Medicine, Beijing 100021, P.R. China; *Department of Free Radical Biology andAging, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104.Epilepsy is one of the most common forms of nervous disease. It is caused by genetic and environment factors,such as genetic defect, damage in brain and nervousness by stress or scare. Kainic acid (KA) induces seizuresand has been widely used as an animal model for human temporal lobe epilepsy. Our preliminary studyshowed that long-term induced genes in hippocampus play an important role in the regulation of recurrentseizures induced by KA treatment. In order to identify this long-term FRA, we have constructed a cDNAlibrary derived from the hippocampus 6 weeks after KA treatment and screened it with an antibody raisedagainst the highly conserved M-peptide region of c-Fos and the other FRA. A gene, MP13, was cloned and itcontained a 1662 bp open reading frame which coded for a 554-amino-acid protein. The expressed MP13protein was specifically recognized by the M-peptide antibody but not by c-Fos, Fos B, Fra1, and Fra2 antibodies.Sequence analysis revealed that MP13 has a leucine zipper region, a glutamine repeat region, and has highsequence similarity to the activator of the small GTPase Rab5. Gel retardation analysis for the translatedMP13 protein in vitro revealed that the binding of the MP13 protein to other proteins was GTP related. Theseresults suggested that MP13 functions as a GTP related factor.S-N-5IN VIVO STUDY OF NEUROPEPTIDE Y IN FOCAL CEREBRAL ISCHAEMIAS.H. CHEN. R.T.F. CHEUNGDepartment of Medicine, Faculty of Medicine, The University of Hong Kong, Hong KongBackground and Purpose: Neuropeptide Y (NPY), an endogenous peptide neurotransmitter, has been implicatedin the regulation of many physiological functions and in the pathogenesis of many human diseases. Previousmiddle cerebral artery occlusion (MCAO) experiments have shown an increase in NPY within the peri-infarctcortex. We studied the effects of exogenous NPY on infarction volume.Methods: Adult male Sprague-Dawley rats were anaesthetised with sodium pentobarbital to undergo reversibleright-sided endovascular MCAO for 2 hours. NPY or vehicle was given via one of three ways: intracarotidinjection (10 ug/kg) at the beginning of reperfusion; intracisternal injection (10 or 30 ug/kg) at 30 minutes ofischaemia; intra-cerebroventricular (ICV) injection (10 ug/kg) at 30 min of ischaemia. Body temperature wasmaintained constant, and haemodynamic parameters were monitored during anaesthesia. Laser dopplerflowmetry (LDF) was used to record cerebral blood flow (CBF) during ischaemia and reperfusion. The ratswere decapitated on day 3, and their brains were cut into 2-mm thick coronal slices before staining with 2%triphenyltetrazolium chloride for determination of infarction volume.Results: The relative infarction volumes in the NPY-treated rats were 40.0±4.7% (mean± SEM; 10 rats) afterintracarotid injection, and 30.3± 5.1% (9 rats) after ICV injection, whereas the infarction volumes were smallerin the control rats (24.0± 3.1% [7 rats] in intracarotid controls and 15.7± 3.6% [7 rats] in ICV controls; P < 0.05,2-tailed student's t test). Following intra-cisternal injection of NPY, the relative infarction volumes were27.8±3.4% (10 ug/kg; 11 rats) and 29.5±3.7% (30 ug/kg; 12 rats), which were not significantly different fromthat of control group (21.6± 3.1%; 8 rats). A major reduction in CBF during reperfusion was observed, especiallyafter intra-carotid or ICV injection.Conclusions: Exogenous NPY administered by intra-carotid or ICV injection increases the infarction volume.Data from laser Doppler flowmetry indicates that NPY injection produces a significant reduction in CBFduring reperfusion.- 53 -

In vivo study of neuropeptide Y in focal cerebral ischaemia

http://hub.hku.hk/bitstream/10722/46813/1/52685.pdf

In vivo study of neuropeptide Y in focal cerebral ischaemia

Abstract

Similar works

Full text

Available Versions

HKU Scholars Hub