Prostacyclin is mainly produced by-

Ans. is 'b' i.e., Vascular endotheliumArachidonic acid metabolites During inflammation, various biologically active lipid mediators are derived from membrane phospholipid. o Arachidonic acid is derived from dietry sources or by conversion from the essential fatty acid (linoleic acid).It does not occur free in cell but is normally esterified in membrane phospholipid.When phosphilipase A2 is activated, it releases arachidonic acid from membrane phospholipids.From arachidonic acid, mediators of inflammation are synthesized by two different pathway.