Arachidonic acid Metabolism at a glance

              We know cell membrane phospholipids with the help of phospholipase give birth of Arachidonic Acid.

            This Arachidonic Acid causes synthesis of Prostaglandin with the help of Cyclooxygenase enzyme and also causes synthesis of Leukotrine with the help of Lipooxygenase enzyme.

            When we give Steroid as a painkiller or any other purpose it blocks the cell membrane phospholipid to Arachidonic Acid synthesis by inhabiting Phospholipase enzyme .So no gain & no pain.

            But if we give Aspirin, Indomethacin or any other NSAID, it blocks Prostaglandin synthesis by inhabiting Cyclooxygenase pathway. So no pain but some gain.

            On the other hands meclofenamate sodium, Hypericuns perforatum, Zileuton block synthesis of Leukotrine by Lipooxygenase enzyme.( there are also some Leukotrine receptor blocker used in Br.Asthma,COPD ;Such as Montelukast , Zafirlukast ,Pranlukast )

Now

·         All the Prostaglandin derivatives are Vasodilator except Thromboxan-A_2.

·         All the Prostaglandin derivatives Causes Palatelet aggregation Except Prostaglandin-I_2.

·         All the leucotrines are vasoconstrictor except Leucotrine-B₄ is potent Chemotactic agent

·         All the leucotrines are Bronchoconstrictor except Leucotrine-B_4.

·         All the leucotrines increase vascular permeability.





Collected & Concise only for postgraduate student,pictures are collected from Google.