Abstract
We have examined whether interleukin (IL)-1beta modulates phospholipase A2 (PLA2) activity in ventricular myocytes. PLA2 activity was measured in isolated membrane and cytosol fractions with (16:0,[3H]18:1) plasmenylcholine and (16:0,[3H]18:1) phosphatidylcholine in the absence and presence of Ca2+. When measured in the absence of Ca2+ with plasmenylcholine, exposure to 5 ng/ml IL-1beta caused an increase in membrane-associated PLA2 activity for 10 min that returned to basal levels by 20 min. In the presence of Ca2+ with phosphatidylcholine, IL-1beta had no effect on membrane-associated PLA2 but decreased cytosolic PLA2 activity. Additionally, IL-1beta caused an increase in arachidonic acid release in 20 min. Pretreatment with E-6-(bromomethylene)tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one, a selective Ca2+-independent PLA2 inhibitor, blocked IL-1beta-induced increases in both PLA2 activity and arachidonic acid release. Exposure to IL-1 receptor antagonist (IL-1RA) alone had no effect on membrane-associated PLA2 activity. When incubated with IL-1beta, IL-1RA inhibited the IL-1beta-enhanced PLA2 activity. These results show that, via activation of its receptors, IL-1beta stimulates specifically membrane-associated Ca2+-independent plasmalogen-selective PLA2 in rat ventricular myocytes.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
