Avtor/Urednik     Zidar, Nina; Odar, Katarina; Glavač, Damjan; Jerše, Maja; Zupanc, Tomaž; Štajer, Dušan
Naslov     Cyclooxygenase in normal human tissues - is COX-1 really a constitutive isoform, and COX-2 an inducible isoform?
Tip     članek
Vir     J Cell Mol Med
Leto izdaje     2008
Jezik     eng
Abstrakt     Cyclooxygenase (COX) is a key enzyme in prostanoid synthesis. It exists in two isoforms, COX-1 and COX-2. COX-1 is referred to as a "constitutive isoform", and is considered to be expressed in most tissues under basal conditions. In contrast, COX-2 is referred to as an "inducible isoform", which is believed to be undetectable in most normal tissues, but can be upregulated during various conditions, many of them pathologic. Even though the role of COX in homeostasis and disease in now well appreciated, controversial information is available concerning the distribution of COX isoforms in normal human tissues. There is mounting evidence that it is much more complex than generally believed. Our aim was therefore to analyse the expression and distribution of COX isoforms in normal human tissues, using immunohistochemistry, western blotting and real-time reverse transcriptase polymerase chain reaction. Autopsy samples from 20 healthy trauma victims and samples from 48 biopsy surgical specimens were included. COX-1 was found in blood vessels, interstitial cells, smooth muscle cells, platelets and mesothelial cells. In contrast, COX-2 was found predominantly in the parenchymal cells of many tissues, with few exceptions, for example the heart. Our results confirm the hypothesis that the distribution of COX isoforms in healthy tissues is much more complex than generally believed. This and previous studies indicate that both isoforms, not only COX-1, are present in many normal human tissues, and that both isoforms, not only COX-2, are upregulated in various pathologic conditions. We may have to revise the concept of "constitutive" and "inducible" COX isoforms.
Deskriptorji     PROSTAGLANDIN-ENDOPEROXIDE SYNTHASE
IMMUNOHISTOCHEMISTRY
POLYMERASE CHAIN REACTION
BLOTTING, WESTERN
AUTOPSY
BIOPSY