"48"^^ . . . . "NMDA"@cs . "glutam\u00E1tov\u00E9ho receptoru NMDA"@cs . . . . . . . . "NMDA receptory"@cs . . . . . . . . "698786"^^ . . . . . . . . . "Na N-metyl-D-aspart\u00E1t receptor (tak\u00E9 zn\u00E1m\u00FD jako NMDA receptor nebo NMDAR), je glutam\u00E1tov\u00FD receptor a iproteinov\u00FD iontov\u00FD kan\u00E1l v nervov\u00E9 bu\u0148ce. NMDA receptor je jedn\u00EDm ze t\u0159\u00ED typ\u016F ionotropn\u00EDch glutam\u00E1tov\u00FDch receptor\u016F vedle AMPA a kain\u00E1tov\u00FDch receptor\u016F. Aktivuje se, kdy\u017E glutam\u00E1t a glycin (nebo D-serin) se nav\u00E1\u017Ee a umo\u017En\u00ED pozitivn\u011B nabit\u00FDm iont\u016Fm proudit skrz bun\u011B\u010Dnou membr\u00E1nu. NMDA receptor je d\u016Fle\u017Eit\u00FD pro regulaci synaptick\u00E9 plasticity a pam\u011B\u0165ov\u00E9 funkce.NMDAR je specifick\u00FD typ ionotropn\u00EDho glutam\u00E1tov\u00E9ho receptoru. N\u00E1zev NMDA receptoru poch\u00E1z\u00ED od zkatky n\u00E1zvu jeho agonisty N-methyl-D-aspart\u00E1tu (NMDA), kter\u00FD se selektivn\u011B v\u00E1\u017Ee na NMDA receptor a nikoli na jin\u00E9 glutam\u00E1tov\u00E9 receptory. Aktivace NMDA receptor\u016F vede k otev\u0159en\u00ED iontov\u00E9ho kan\u00E1lu, kter\u00FD je neselektivn\u00ED pro kationty s kombinovan\u00FDm reverzn\u00EDm potenci\u00E1lem okolo 0 mV. P\u0159i otev\u00EDr\u00E1n\u00ED a zav\u00EDr\u00E1n\u00ED iontov\u00E9ho kan\u00E1lu je p\u0159edev\u0161\u00EDm \u0159\u00EDzen nav\u00E1z\u00E1n\u00EDm ligandu, aktu\u00E1ln\u00ED pr\u016Ftok p\u0159es iontov\u00FD kan\u00E1l je nap\u011Btov\u011B \u0159\u00EDzen\u00FD. Extracelul\u00E1rn\u00ED ionty ho\u0159\u010D\u00EDku (Mg2+) a zinku (Zn2+) se mohou v\u00E1zat na konkr\u00E9tn\u00ED m\u00EDsta na receptoru, a t\u00EDm blokovat pr\u016Fchod ostatn\u00EDch kationt\u016F p\u0159es otev\u0159en\u00FD iontov\u00FD kan\u00E1l. Depolarizace bu\u0148ky uvol\u0148uje a vypuzuje ionty Mg2+ a Zn2+ z p\u00F3r\u016F, co\u017E umo\u017E\u0148uje nap\u011B\u0165ov\u011B \u0159\u00EDzen\u00FD tok iont\u016F sod\u00EDku (Na+) a mal\u00E9ho mno\u017Estv\u00ED v\u00E1pn\u00EDku (Ca2+) do bu\u0148ky a drasl\u00EDku (K+) ven z bu\u0148ky.Ca2+ tok p\u0159es NMDARs je pova\u017Eov\u00E1n za rozhoduj\u00EDc\u00ED v synaptick\u00E9 plasticit\u011B, bun\u011B\u010Dn\u00E9ho mechanismus pro u\u010Den\u00ED a pam\u011B\u0165. Otev\u00EDr\u00E1n\u00ED a zav\u00EDr\u00E1n\u00ED (gating) NMDA receptoru je komplexn\u00ED. I p\u0159esto, \u017Ee je to v prvn\u00ED \u0159ad\u011B ligandem \u0159\u00EDzen\u00FD kan\u00E1l, vykazuje i slab\u0161\u00ED nap\u011Btov\u011B z\u00E1vislou modulaci. Ligandov\u00E9 \u0159\u00EDzen\u00ED vy\u017Eaduje spoluaktivaci dvou ligand\u016F: glutam\u00E1tu a d\u00E1le bu\u010F D-serinu nebo glycinu. Nap\u011Btov\u011B z\u00E1visl\u00FD proud kan\u00E1lem je zp\u016Fsoben p\u0159edev\u0161\u00EDm vazbou iont\u016F Mg2+ nebo Zn2+ na protein.Aktivita NMDA receptoru je ovlivn\u011Bna mnoha psychoaktivn\u00EDmi drogami, jako je fencyklidin (PCP), alkohol (ethanol) a dextromethorfanu (DXM). Anestetick\u00E9 a analgetick\u00E9 \u00FA\u010Dinky l\u00E9k\u016F typu ketamin a oxid dusn\u00FD jsou zp\u016Fsobeny \u010D\u00E1ste\u010Dn\u011B tak\u00E9 d\u00EDky vazb\u011B na NMDA receptory. Roku 1989 byl memantin uzn\u00E1n jako nekompetitivn\u00ED antagonista NMDA receptoru, vstupuj\u00EDc\u00ED do kan\u00E1lu receptoru po jeho aktivaci, a t\u00EDm blokuj\u00EDc\u00ED tok iont\u016F.NMDA receptorov\u00E9 kan\u00E1ly hraj\u00ED d\u016Fle\u017Eitou roli v synaptick\u00E9 plasticit\u011B a synaptick\u00E9m vytv\u00E1\u0159en\u00ED hlub\u0161\u00ED pam\u011Bti, u\u010Den\u00ED a formov\u00E1n\u00ED neuronov\u00FDch s\u00EDt\u00ED b\u011Bhem v\u00FDvoje v centr\u00E1ln\u00EDm nervov\u00E9m syst\u00E9mu (CNS). P\u0159ehnan\u00E1 aktivace receptoru zp\u016Fsobuje nadm\u011Brn\u00FD p\u0159\u00EDliv Ca2+ a m\u016F\u017Ee v\u00E9st k excitotoxicit\u011B, kter\u00E1 je zahrnuta do n\u011Bkter\u00FDch neurodegenerativn\u00EDch poruch. Zablokov\u00E1n\u00ED NMDA receptor\u016F by proto mohlo b\u00FDt teoreticky u\u017Eite\u010Dn\u00E9 v l\u00E9\u010Db\u011B t\u011Bchto onemocn\u011Bn\u00ED.Nicm\u00E9n\u011B hypofunkce NMDA receptor\u016F (kv\u016Fli nedostatku glutathionu nebo z jin\u00FDch p\u0159\u00ED\u010Din) zp\u016Fsobuje sn\u00ED\u017Een\u00ED synaptick\u00E9 plasticity a m\u016F\u017Ee m\u00EDt i dal\u0161\u00ED negativn\u00ED n\u00E1sledky. Hlavn\u00EDm probl\u00E9mem vyu\u017Eit\u00ED antagonist\u016F NMDA receptor\u016F pro \u00FA\u010Dely neuroprotekce je, \u017Ee fyziologick\u00E1 aktivita NMDAR je nezbytn\u00E1 pro norm\u00E1ln\u00ED funkci neuron\u016F. \u00DAsp\u011B\u0161n\u00E9 klinick\u00E9 pou\u017Eit\u00ED t\u011Bchto antagonist\u016F by vy\u017Eadovalo blokaci pouze nadm\u011Brn\u00E9 aktivace bez zasahov\u00E1n\u00ED do norm\u00E1ln\u00ED funkce."@cs . . . "Na N-metyl-D-aspart\u00E1t receptor (tak\u00E9 zn\u00E1m\u00FD jako NMDA receptor nebo NMDAR), je glutam\u00E1tov\u00FD receptor a iproteinov\u00FD iontov\u00FD kan\u00E1l v nervov\u00E9 bu\u0148ce. NMDA receptor je jedn\u00EDm ze t\u0159\u00ED typ\u016F ionotropn\u00EDch glutam\u00E1tov\u00FDch receptor\u016F vedle AMPA a kain\u00E1tov\u00FDch receptor\u016F. Aktivuje se, kdy\u017E glutam\u00E1t a glycin (nebo D-serin) se nav\u00E1\u017Ee a umo\u017En\u00ED pozitivn\u011B nabit\u00FDm iont\u016Fm proudit skrz bun\u011B\u010Dnou membr\u00E1nu."@cs . "NMDA receptor"@cs . . . . . . "NMDA receptor"@cs . . . "16549794"^^ . . . "NMDA receptor\u016F"@cs . . "13449"^^ . .