tailieunhanh - Ebook Medical pharmacology at a glance (7th edition): Part 2

(BQ) Part 2 book "Medical pharmacology at a glance" presents the following contents: Lipid-lowering drugs, general anaesthetics, agents used in anaemias, anxiolytics and hypnotics, antiepileptic drugs, antipsychotic drugs, opioid analgesics, drugs used in nausea and vertigo, antidiabetic agents,. and other contents. | 20 Lipid-lowering drugs Endocytosis HMG CoA inhibitors Lysis Anionic exchange resins CE colestyramine colestipol LDL atorvastatin simvastatin pravastatin others Cholesterol LDL-R nicotinic acid Increase A Fibrates Inhibit A VLDL BA Bile duct A BA BA HMG CoA HMG CoA reductase mevalonate – CE Cholesterol + TG Portal vein BA TG HDL A BA LDL receptor bezafibrate fenofibrate others Activate Lipoprotein lipase (in muscle and adipose tissue capillaries) chol CE A BA Bile acid excretion INHIBITOR of cholesterol absorption ezetimibe Lipids, such as triglycerides and cholesterylesters, are insoluble in water and are transported in plasma in the core of particles (lipoproteins) that have a hydrophilic shell of phospholipids and free cholesterol. This surface layer is stabilized by one or more apolipoproteins, which also act as ligands for cell surface receptors. About two-thirds of plasma lipoproteins are synthesized in the liver (middle, shaded (yellow)). Triglycerides (TG) are secreted into the blood as very-low). In muscle and adipose tissue, the density lipoproteins (VLDL, capillaries (right) possess an enzyme, lipoprotein lipase ( ), that hydrolyses the triglycerides to fatty acids; these then enter the muscle cells (for energy) and adipocytes (for storage). The residual particles containing a core rich in cholesterylester (CE) are called low-density lipoprotein (LDL) particles. The liver and other cells possess LDL ) that remove LDL from the plasma by endocytosis receptors ( (top figure shaded orange). The hepatic receptor-mediated removal of LDL is the main mechanism for controlling plasma LDL levels. Fatty acids and cholesterol from ingested dietary fat are re-esterified in mucosal cells of the intestine and form the core of chylomicrons, which enter the plasma via the thoracic duct. Fatty acids are Fatty acids LDL hydrolysed from the chylomicrons by lipoprotein lipase, and the residual triglyceride-depleted remnants are removed by .