Tnf¦Á, Aii And Mmldl Induced Endothelial Cell Membrane Abnormalities, Calcium Activated Potassium Channel

Introductionratherosclerosis and hypertensin are associated with adherence of blood cell, thrombosis, vasoconstriction and proliferation of vascular smooth muscle. A lot of cardiovascular risk factors act on vascular endothelium leading to endothelial cells dysfunction which induced the above pathological changes through different mechanisms.Stimulation of endothelial cells with tumor necrosis factor-a(TNFa), generates two types of signals rone that initiates programmed cell death, and the other one leads to activation of the transcription factor NF-kB and subsequently to the inflammatory response. Endothelial cells are exposed to angiontensinII(AII), which also induces apoptosis. In addition,AII activates NOS and increases the synthesis of NO. The interaction between NO and superoxide generates peroxynitrite. The latter is well known as a mediator of NO toxicity. Minimally modified low density lipoprotein(mmLDL)plays a significant role in early stage of atherogenesis. It promots adherence of monocyte to endothelial and produce foma cells.The increasing of cytoplasmic calcium concentration is companied by endothelial cell dysfunction. Cytoplamic calcium elavation depends on calcium influx from extracellular space and intracellular calcium releasing from calcium store. Electrochemical gradient for calcium influx is affected by membrane potential. So the postassium channel, forming and regulating the membrane potential, especially maxi-conductance calcium activated potassium channel is very important in the regulation of...