Methyl eicosatetraenoate (all cis-5,8,11,14)

This high purity, polyunsaturated fatty acid is the methyl ester of arachidonic acid and is ideal as a standard. Arachidonic acid, an ω-6 fatty acid, is an essential fatty acid for most mammals and has many important biological functions in signaling, inflammation, nervous system functions and other processes. It is usually most abundant as a membrane lipid where it is esterified mainly at the sn2 position of phospholipids. It mediates numerous actions that range from induction of cell death to promotion of cell survival and enhancement of neurite extension. Some functions of arachidonic acid include modulation of the activities of protein kinases and ion channels, inhibition of neurotransmitter uptake, enhancement of synaptic transmission, and induction of cellular adhesion.{50607} Arachidonic acid has been suggested to be a critical mediator in amyloidbeta induced pathogenesis, leading to learning, memory, and behavioral impairments in Alzheimer's disease.{50608} In the CNS it plays a fast messenger role in synaptic modulation. An imbalance in n-6 fatty acid and n-3 fatty acid dietary intake has been suggested as the reason for several diseases, including inflammatory and autoimmune diseases, and has recently been blamed predominantly on arachidonic acid because it is a precursor for eicosanoids which have pro-inflammatory and immuno-regulatory activity.{50609} Arachidonic acid is also a precursor for autacoids and prostaglandins in mammals. It has been shown to trigger calcium signals in endothelial cells derived from human breast carcinoma but not from healthy cells. This has caused it to be considered a component of the tumor microenvironment although some results suggest that release of arachidonic acid from membrane lipids may help to prevent tumors.{13553}