prostaglandin

1. (biochemistry) Any of a group of naturally occurring lipids derived from the C₂₀ acid prostanoic acid; they have a number of physiological functions and may be considered to be hormones.Examples: "This enzyme generates an inflammatory mediator known as prostaglandin, which triggers pain and other aspects of inflammation."; "Indeed, it’s possible to create the full storm of cold symptoms with no cold virus at all, but only a potent cocktail of the so-called inflammatory mediators that the body makes itself[,] among them, cytokines, kinins, prostaglandins and interleukins, powerful little chemical messengers that cause the blood vessels in the nose to dilate and leak, stimulate the secretion of mucus, activate sneeze and cough reflexes and set off pain in our nerve fibers."