In the article I am presenting tomorrow in class, prostaglandins are frequently mentioned. However, the article does not provide a good explanation for the role of prostaglandins in inflammation. They also focus solely on its negative effects. Hopefully, some of you have the chance to read this post before tomorrow, so that you can come in with a better understanding of the action of prostaglandins.
Prostaglandins are derived from arachidonic acid. They play a role in sustaining homeostatic functions and they also help to mediate pathogenic mechanisms (inflammation for example). They are made from arachidonate with the help of cyclooxygenase enzymes (COX-1 and COX-2). Their synthesis is blocked by non-steroidal anti-inflammatory drugs. Prostaglandins promote inflammation and also help to resolve it.
PGE2 is one of the most abundant prostaglandins in the body. It helps to mediate "immune responses, blood pressure, gastrointestinal integrity, and fertility", among other things. The dysregulation of PGE2 can actually cause certain types of pathology.
PGE2 leads to the classical signs of inflammation: redness, pain, and swelling. Redness and swelling are caused by increased blood flow, which is mediated by vasodilation caused in part by PGE2. Pain is caused by PGE2 acting on peripheral sensory neurons and on other sites in the brain and spinal cord.
PGE2 can have pro-inflammatory as well as anti-inflammatory effects, depending on the receptor type that it is bound to. It can regulate the function of many cells including macrophages, dendritic cells, T cells, and B cells. As a pro-inflammatory mediator, it can act on T cells to bias a Th1 or Th2 response. As an anti-inflammatory mediator, it can act on neutrophils, natural killer cells, and monocytes.
Ricciotti, Emanuela, and Garret A. FitzGerald. "Prostaglandins and Inflammation."Prostaglandins and Inflammation. American Heart Association, 2011. Web. 08 Dec. 2013.
Very interesting topic. I hear about prostaglandins over and over in many physio classes, but never understood/was taught the mechanism of how it would respond to stimuli and causes pain. Additionally, it was new for me that prostaglandins can also have affect on gastrointestinal integrity and fertility. Nicely done post. Thank you.
ReplyDeleteThanks for well informing us Diana. So this prostaglandins can do both, either induce inflammation or inhibit inflammation, and in that have two effects. So which receptor is best for it? Is it better if it's a pro inflammatory or at an anti-inflamatory? Just some questions that came to my mind. Thanks
ReplyDeleteI never thought about NSAIDs and their link to fertility with prostaglandins that is really interesting, found this article saying "Its inhibition is thought to cause luteinised unruptured follicle (LUF) syndrome, an anovulatory condition characterised by clinical signs of ovulation but in the absence of follicular rupture and ovum release. The evidence linking regular NSAID use to reversible LUF syndrome comes from animal studies and three clinical studies."
ReplyDeletehttp://www.ncbi.nlm.nih.gov/pubmed/12113640