{"id":1523,"date":"2018-05-17T18:42:18","date_gmt":"2018-05-17T17:42:18","guid":{"rendered":"https:\/\/ellipse.3ip.eu\/?p=1523"},"modified":"2024-06-03T12:53:22","modified_gmt":"2024-06-03T10:53:22","slug":"el-mur-protector-del-cervell-la-barrera-hematoencefalica","status":"publish","type":"post","link":"https:\/\/ellipse.prbb.org\/ca\/el-mur-protector-del-cervell-la-barrera-hematoencefalica\/","title":{"rendered":"El mur protector del cervell: la barrera hematoencef\u00e0lica"},"content":{"rendered":"<p>El <strong>cervell<\/strong> \u00e9s un dels \u00f2rgans m\u00e9s importants i delicats. Per aquest motiu, la naturalesa l\u2019ha dotat d&#8217;un sistema defensiu especial, la <strong>barrera hematoencef\u00e0lica (BHE)<\/strong>, una barrera semipermeable que separa el torrent sanguini que arriba al <strong>sistema nervi\u00f3s central<\/strong> (cervell i medul\u00b7la espinal) del l\u00edquid cerebral extracel\u00b7lular.<\/p>\n<figure id=\"attachment_1569\" aria-describedby=\"caption-attachment-1569\" style=\"width: 400px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-1569 size-medium\" src=\"https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2018\/12\/Ellipse-113-Blood_Brain_Barrier-400x220.jpg\" alt=\"Il\u00b7lustraci\u00f3 de la barrera hematoencef\u00e0lica\" width=\"400\" height=\"220\" srcset=\"https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2018\/12\/Ellipse-113-Blood_Brain_Barrier-400x220.jpg 400w, https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2018\/12\/Ellipse-113-Blood_Brain_Barrier-768x423.jpg 768w, https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2018\/12\/Ellipse-113-Blood_Brain_Barrier-1090x600.jpg 1090w, https:\/\/ellipse.prbb.org\/wp-content\/uploads\/2018\/12\/Ellipse-113-Blood_Brain_Barrier.jpg 2044w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><figcaption id=\"caption-attachment-1569\" class=\"wp-caption-text\">Il\u00b7lustraci\u00f3 de la barrera hematoencef\u00e0lica. De Sykepleiepluss CC BY-SA 3.0<\/figcaption><\/figure>\n<p>La BHE est\u00e0 feta per <strong>c\u00e8l\u00b7lules endotelials<\/strong>. Aquestes es troben a la superf\u00edcie interna de tots els vasos sanguinis del cos per\u00f2, quan arriben al cervell, la seva distribuci\u00f3 espacial es torna m\u00e9s densa: estan m\u00e9s a prop, formant una mena de xarxa estreta. D&#8217;aquesta manera restringeixen el pas de subst\u00e0ncies del torrent sanguini molt m\u00e9s que les c\u00e8l\u00b7lules endotelials a la resta dels capil\u00b7lars del cos.<\/p>\n<p>A m\u00e9s d&#8217;aquesta primera barrera de \u00abcontenci\u00f3\u00bb, envoltant la superf\u00edcie exterior dels capil\u00b7lars hi ha els <strong>astr\u00f2cits<\/strong>. D&#8217;una banda, aquestes c\u00e8l\u00b7lules proporcionen suport bioqu\u00edmic a les c\u00e8l\u00b7lules endotelials i, d&#8217;altra banda, s\u00f3n el cam\u00ed que uneix els vasos sanguinis i les neurones, ja que tamb\u00e9 s\u2019entrellacen al voltant de la neurona. S\u00f3n les c\u00e8l\u00b7lules responsables de permetre l&#8217;intercanvi d&#8217;alguns gasos, mol\u00e8cules liposolubles, glucosa i amino\u00e0cids entre neurones i vasos sanguinis.<\/p>\n<p>El principal avantatge de la BHE \u00e9s que impedeix el pas al cervell de subst\u00e0ncies lipof\u00edliques, com ara <strong>subst\u00e0ncies<\/strong> potencialment <strong>neurot\u00f2xiques<\/strong>, virus i bacteris. Aix\u00ed, podem dir que el cervell t\u00e9 una protecci\u00f3 molt efectiva que li permet treballar correctament. Per\u00f2, quan hi ha problemes \u2014 <strong>malalties neurodegeneratives<\/strong> com el <strong>Parkinson <\/strong>o<strong> l&#8217;Alzheimer<\/strong>, o un <strong>accident cerebrovascular<\/strong> o un tumor cerebral\u2014 i el cervell necessita ajuda des de fora, els f\u00e0rmacs no hi poden arribar o ho fan de manera ineficient. Aix\u00f2 \u00e9s degut al fet que la BHE reconeix m\u00e9s del 97 % dels f\u00e0rmacs actuals com a subst\u00e0ncies potencialment t\u00f2xiques i en bloqueja pas.<\/p>\n<p>Aquesta \u00e9s una de les raons principals per les quals el tractament a llarg termini contra la malaltia de Parkinson o l&#8217;Alzheimer no funciona i explica per qu\u00e8 el <strong>glioblastoma<\/strong>, el tumor m\u00e9s com\u00fa del cervell, \u00e9s un dels c\u00e0ncers m\u00e9s mortals. Hi ha diverses l\u00ednies de recerca en curs per tractar de desenvolupar nous f\u00e0rmacs que poden travessar la BHE, i t\u00e8cniques que obren petites \u00abfinestres\u00bb a la BHE i permeten que els f\u00e0rmacs arribin a la regi\u00f3 cerebral on se\u2019n necessiten. Per\u00f2 cap d&#8217;elles ha funcionat fins ara en humans; els \u00fanics resultats reeixits han estat a la fase precl\u00ednica en diferents animals. Encara necessitem molts anys i molta recerca per traduir-los en una realitat cl\u00ednica.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>La barrera hematoencef\u00e0lica (BHE) protegeix el cervell, per\u00f2 tamb\u00e9 hi dificulta l&#8217;acc\u00e8s quan volem utilitzar f\u00e0rmacs, per exemple en casos de neurodegeneraci\u00f3. <\/p>\n","protected":false},"author":2,"featured_media":2504,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[30],"tags":[320,263,513,317,231,568],"new-type":[35],"class_list":["post-1523","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ciencia-i-societat","tag-alzheimer","tag-cervell","tag-ciencia-al-descobert","tag-neurobiologia","tag-parkinson","tag-sang","new-type-noticies"],"acf":[],"_links":{"self":[{"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/posts\/1523","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/comments?post=1523"}],"version-history":[{"count":5,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/posts\/1523\/revisions"}],"predecessor-version":[{"id":42934,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/posts\/1523\/revisions\/42934"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/media\/2504"}],"wp:attachment":[{"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/media?parent=1523"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/categories?post=1523"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/tags?post=1523"},{"taxonomy":"new-type","embeddable":true,"href":"https:\/\/ellipse.prbb.org\/ca\/wp-json\/wp\/v2\/new-type?post=1523"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}