425 KB48 KB199420252006Gartner, UrškaKočevar, Urškaštevilka:3letnik:45str. 237-252ISSN:0025-8121COBISSID:22677209URN:URN:NBN:SI:doc-PMHHDZDDslMedicinski razglediMedicinski razglediAutopsybiokemijaencimiEnzymologyheartHistocitokemijaHistocytochemistryMiokardni infarktMyocardial InfarctionObdukcijaPathologypatološka histologijaProstaglandin-endoperoksidna sintazaProstaglandin-Endoperoxide Synthaseprostaglandinisrcesrčni infarktIzražanje encimov ciklooksgenaza-1 in cikloksigenaza-2 v zdravem srcu in v srčnem infarktu pri človeku| Expression of cyclooxygenase-1 and cyclooxygenase-2 enzymes in normal heart and in myocardial infarction|Cyclooxygenase (COX) is a key enzyme in prostanoid synthesis which plays an important role in many cell functions. COX exists in two isoforms: COX-1 and COX-2. Our aim was to analyse the expression of both COX isoforms in the normal human heart and in myocardial infarction, with a hypothesis that COX-1 is expressed mostly or exclusively in the normal heart and COX-2 in myocardialinfarction. Our study included autopsy samples of heart tissue divided into 2 groups: one consisted of heart tissue samples from 10 healthy persons who died in car accidents, and the other of heart tissue samples from 35 patients with myocardial infarction. Tissue samples were stained with hematoxylline and eosin and immunohistochemistry was used for detection of COX-1 and COX-2. In the normal heart, COX-1 is expressed in blood vessels and endocardium, but not in cardiomyocytes. COX-2 is not expressed in the normal heart or very rarely in occasional myocytes. In contrast, COX-2, but not COX-1is induced in cardiomyocytes in myocardial infarction. Both isoforms are present in components of granulation tissue and fibrous tissue. COX-1-positivity was intense and almost diffuse, while COX-2 positivity was focal. Our results indicate that COX-1 maintains normal homeostasis in the heart and that inflammatory reaction in myocardial infarction is probably mediated by COX-2. It appears that both COX-1 and COX-2 contribute to the healing processes and scar formation after myocardial infarctionCiklooksigenaza (COX) je ključni encim pri nastajanju prostanoidov, ki vplivajo na številne celične funkcije. Poznamo dve izoformi COX, to sta COX-1 in COX-2. V naši nalogi smo določili izražanje obeh izoform COX v zdravem srcuin v srčnem infarktu pri človeku. Predvidevali smo, da je COX-1 prisotna predvsem ali izključno v zdravem srcu, COX-2 pa v srčnem infarktu. Raziskava je bila narejena na obdukcijskih vzorcih srca, ki smo jih razdelili v dve skupini: v prvi so bili vzorci srca 10 zdravih oseb, ki so umrle v prometnih nesrečah, v drugi pa obdukcijski vzorci srca 35 bolnikov, ki so umrli za posledicami srčnega infarkta. Vse vzorce smo obarvali s hematoksilinom in eozinom, COX-1 in COX-2 smo prikazali z imunohistokemično metodo. V zdravem srcu je COX-1 izražena v žilah in endokardu, v miocitih pa ne; COX-2 v zdravemsrcu večinoma ni prisotna ali pa le v redkih miocitih. V srčnem infarktu se v miocitih sproži sinteza COX-2, ne pa tudi COX-1. Obe izoformi sta prisotni v sestavinah granulacijskega tkiva in veziva; reakcija na COX-1 je intenzivna in skoraj razpršena, reakcija na COX-2 pa žariščna. Na podlagi teh rezultatov sklepamo, da je za uravnavanje homeostaze v srcu v celoti odgovorna COX-1. Vnetno reakcijo ob srčnem infarktu verjetno posreduje predvsem COX-2, pri celjenju in nastanku brazgotine po SI pa sodelujeta obe izoformi, vendar je verjetno vloga COX-1 pomembnejša kot vloga COX-2TEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaDruštvo Medicinski razgledi