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8 Eicosanoids by heheheehheheehheegeg.pptx
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- 2. Contents of theLecture Definition of Eicosanoids Types of Eicosanoids Importance of Eicosanoids Biosynthesis of Eicosanoids Structure & Functions of Prostaglandin Effects of Thromboxanes Leukotrienes & their role
- 3. History • Prostaglandins werediscovered in the 1930's. • Ulf von Euler found that seminal fluid and seminal vesicles from most animals including man contain a substance which causes contraction of the smooth muscle of the uterus. • He named this new substance prostaglandin sincethey were originally thought to be secreted bytheprostrategland.
- 4. EICOSANOIDS - Definition Anyof a class of compounds that are derived from polyunsaturated fatty acids as arachidonic acid and are involved in cellular activities. Example: Prostaglandins, Leukotrienes, and Thromboxanes
- 5. EICOSANOIDS - Types PROSTAGLANDINS THROMBOXANESLEUKOTRIENES LIPOXINS
- 6. They are Physiologicallyand Pharmacologically active compounds Act as local hormones functioning through G-Proteins EICOSANOIDS –Importance
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- 9. Prostaglandins Any of agroup of potent hormone like substances that are produced in various mammalian tissues, derived from Arachidonic acid, and mediate a wide range of physiological functions, such as control of blood pressure, contraction of uterine, smooth muscle, and modulation of inflammation
- 10. CHEMICAL STRUCTURE All prostaglandinsare considered to be derived from the 20 C cyclic saturated fatty acid, Prostanoic Acid. The five carbon ring is saturated. All naturally occurring PGs have an alpha- oriented OH group at C15.
- 11. Prostaglandins PGs are notstored; precursor fatty acids are stored in membrane as phospholipids. Arachidonic acid is released by the action of Phospholipase A2 on phospholipids Synthesis is catalysed by prostaglandins H synthase(PGHS). It contains two separate enzymes (cyclo-oxygenase & peroxidase). PGG2 and PGH2 are formed as intermediates during synthesis of other PGs.
- 12. Functions of Prostaglandins Effects onGIT Effects on Inflamm ation Effects on Resp tract Effects on uterus Effects on CVS
- 13. Functions of Prostaglandins PGI2 Vasodilatation Inhibitsplatelet aggregation PGA and PGE class prostaglandins lower blood pressure. Effects on CVS
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- 15. PGF2 Stimulates uterine muscles Inducinglabor Effects on uterus Functions of Prostaglandins
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- 17. PGF-Bronchoconstriction PGE-Bronchodilator PGE- series areused in aerosols for relieving vasospasm Effects on Respiratory tract Functions of Prostaglandins
- 18. Effects on Respiratorytract • Effects on uterus
- 19. PGE2 Involved in inflammatory responseby increasing capillary permeability. Effects on Inflammation Functions of Prostaglandins
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- 21. PGE2 suppress gastric acid secretionand intestinal motility and used in treatment of acid peptic disease Effects on GIT Functions of Prostaglandins
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- 23. THROMBOXANE EFFECTS Increase plateletaggregation Vasoconstriction Mobilize intracellular calcium Smooth muscle contraction Bronchoconstriction
- 24. EICOSANOIDS FUNCTIONS Summary ofuses Use Preparation Abortion PgE1 Cervical ripening PgE1 / E2 Peptic ulcer PgE1 Glaucoma PgE1-Latanoprost PPH PgI2 PDA PgE1
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- 29. LEUKOTRIENES Increase chemotaxis Facilitate inflammation& allergic reactions Contraction of smooth muscle Bronchoconstriction Vasoconstriction
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