Pharmacology II

waveurflag's version from 2018-03-01 02:51


Question Answer
Stable Atherosclerotic PlaqueRich in smooth muscle cells and ECM, has thick fibrous cap
Vulnerable Atherosclerotic PlaqueRich in macrophages and foam cells, has fatty core & thin fibrous cap
CholesterolEssential structural component of cell membranes Precursor for biosynthesis of steroid hormones, bile and vitamin D Synthesized in numerous cells (mainly liver) It is recycled Excreted by the liver (via bile) into the digestive tract Re-absorbed by the small intestine
Triglyceride (TG)Consists of a glycerol and 3 fatty acids (FAs) Saturated fats (no double C=C bonds, e.g. animal fats) Unsaturated fats (some double C=C bonds, e.g. vegetable oil). They cannot be absorbed by the intestine (need to be cleaved into monoacylglycerol + 2 FAs by pancreatic lipase). They provide FAs to tissues (muscles, adipocytes)
LipoproteinsParticles that enable fats to be carried in the bloodstream. Consist of an hydrophobic core containing triglycerides (TGs) and cholesteryl esters (CEs) surrounded by unesterified cholesterol, phospholipids and apoproteins
ApolipoproteinsProteins that bind lipids and help the transport of lipoproteins in blood Function as: structural components of lipoprotein particles cofactors for enzymes ligands for cell-surface receptors
Apo-AFound on chylomicrons (apo-A4) and HDL (apo-A1) Cofactor for LCAT (lecithin cholesterol acyltransferase)
Apo-B48Formed in the intestine Found on chylomicrons and chylomicron remnants Binds the remnant receptors and involved in return of chylomicron remnants to the liver
Apo-B100Formed in liver Found on VLDLs, IDLs and LDLs Binds the LDL receptor
Apo-CIIFound on chylomicrons, VLDLs and HDLs Cofactor for lipoprotein lipase (LPL)
Apo-E Primarily formed in liver Found on all lipoproteins except LDLs Involved in reuptake by liver Interact with different receptors
ChylomicronsProduced in enterocytes (intestine) High in TGs, low in cholesterol Carry fats from the intestine to peripheral tissues in need of fatty acids for energy or fat production (muscles, adipocytes) Associated with apo-B48, apo-A4, apo-CII and apo-E Get into the bloodstream through the thoracic duct where they are cleaved by lipoprotein lipase (LPL) into chylomicron remnants (richer in cholesterol)
VLDLs (very low density lipoproteins):Produced in hepatocytes (liver) High in TG, low in cholesterol Carry fats from liver to peripheral tissues (adipocytes, muscles) Associated with apo-B100, apo-CII and apo-E Released from liver into the bloodstream Hydrolyzed by LPL into IDL (aka VLDL remnants)
IDLs (intermediate density lipoprotein):Produced from VLDL breakdown Associated with apo-B100 and apo-E Some IDLs interact with the liver remnant receptors, are endocytosed and hydrolyzed Some IDLs are further hydrolyzed by the hepatic lipase and LPL into LDLs
LDLs (low density lipoproteins):Produced from hydrolysis of IDLs High in cholesterol, low in TGs Deliver cholesterol to tissue (adipocytes, muscles) Associated with apo-B100 Via apo-B100, LDLs bind the LDL receptor on liver or peripheral tissues, are endocytosed, incorporated into lysosomes and hydrolyzed by the lysosomal acid lipase
HDLs (high density lipoproteins):Produced by liver Smallest and densest lipoprotein Collect fats (mostly cholesterol) from tissues and deliver to: the liver for excretion or re-utilization (aka reverse cholesterol transport) the adrenals, testes and ovary for synthesis of steroid hormones Associated with apo-A1, apo-CII and apo-E Incorporate cholesterol from tissues via interaction of apo-A1 with the ATP-binding cassette transporter A1 (ABCA1). Free cholesterol are then transformed into CEs by the lecithin-cholesterol acyltransferase (LCAT)
LCAT (lecithin-cholesterol acyltransferase):Converts free cholesterol into CEs
CETP (cholesterylester transfer protein):Exchanges CEs of HDLs for TGs of VLDLs