Résumé
<p><b>OBJECTIVE</b>To study the effect of CACNA1H gene mutation G773D on calcium channel function.</p><p><b>METHODS</b>By the overlap extension PCR we introduced G773D mutation into a human Cav3.2acDNA for constructing the mutant. And then using whole cell clamp technique, we studied the alterations of channel behavior in transfected HEK-293 cells.</p><p><b>RESULTS</b>There were no difference in kinetics of activation and inactivation of calcium channel between wild type and mutant. However comparing with the wild-type Cav3.2 channel, G773D mutant could increase the calcium current density significantly.</p><p><b>CONCLUSION</b>CACNA1H gene G773D mutation is able to increase calcium current and neuronal excitability.</p>
Sujets)
Enfant , Enfant d'âge préscolaire , Femelle , Humains , Mâle , Séquence nucléotidique , Canaux calciques de type T , Génétique , Physiologie , Lignée cellulaire , Analyse de mutations d'ADN , Petit mal épileptique , Génétique , Anatomopathologie , Santé de la famille , Données de séquences moléculaires , Mutation , Techniques de patch-clamp , Polymorphisme de nucléotide simpleRésumé
<p><b>AIM</b>To explore the effects of M3 receptor on myocyte apoptosis induced by acute myocardial infarction in rats.</p><p><b>METHODS</b>Rat model was induced by ligation of the anterior branch of the left coronary artery. All animals were divided into four groups: sham-operated group, occlusion group, choline group (10 mg x kg(-1), iv), and 4DAMP (4-diphenylacetoxy-N-methylpiperidine-methiodide) group (0.12 mg x kg(-1), iv). The serum malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were determined. The infarct size areas on the myocardium were identified by TTC staining. The apoptosis in cardiomyocyte was detected by TUNEL assay and apoptosis-related proteins in Bcl-2 and Fas expression were measured by immunohistochemistry assay.</p><p><b>RESULTS</b>M3 receptor agonist choline reduced serum MDA content and increased SOD activity. The myocardial expression of Bcl-2 was increased, whereas the expression of Fas was decreased by choline. However, blockade of M3 receptor by 4DAMP completely inhibited these effects of choline on cardiac myocytes.</p><p><b>CONCLUSION</b>Activation of M3 receptor has protective effect on myocyte apoptosis induced by acute myocardial infarction in rat, and this effect might be related to modulating the expression of some immediateearly genes including Bcl-2 and Fas.</p>