Izražanje 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

slovenian

2006

volume 45, issue 3

Myocardial Infarction    Enzymology    Pathology    Prostaglandin-Endoperoxide Synthase   heart    Autopsy    Histocytochemistry

Društvo Medicinski razgledi
(Obvezni izvod spletne publikacije)

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 infarction.

24.06.2015