Lipoproteins Flashcards
ApoB-100 Abnormality
High blood levels of LDL
Apo E Deficiency or Less Activity
accumulation of IDL and Chylomicron remnants in the blood
ApoC-II Deficiency
elevated levels of chylomicrons and VLDL in the blood
Where is HDL filled with cholesteryl esters?
in the blood
CETP
Connects HDL and VLDL and allows for interchange of totally non polar lipids in the blood. Protein that provides a blood bridge between VLDL and HDL and forms a hydrophobic channel. Allows for movement of cholesterol esters from HDL into VLDL in exchange for TAGs.
Hypoalphalipoproteineimia (low HDL)
Hypolipidemia
characterized by very low HDL-C levels below 35 mg/dl and low Apo A-1 levels. Hereditary: Tangier disease. May be acquired and related to obesity, smoking, and some medical drug treatment
Abetalipoproteinemia (now or low LDL)
Hypolipidemia
rare hereditary disease caused by an abnormal MTP (microsomal TAG transfer protein)
Tangier Disease
rare hereditary disease. Indicated by orange colored tonsils, common symptoms are peripheral neuropathy and premature MI. There is an accumulation of cholesteryl esters found in the tonsils, liver, spleen, and sometimes the corneal opacities
How does a defective ABC-transporter lead to Tangier Disease?
It leads to less substrate for LCAT and to early degradation of the lipid poor apoA-1 in the blood. This results in very low HDL levels
Clinical Features of Abetalipoproteinemia
Fat malabsorption with severe neonatal steatorrhea, failure to thrive, TAG accumulation in liver and intestine. retinitis pigmentosa, progressive blindness, and peripheral neuropathy
What are the two types of hyperlipidemias?
Hypertriacyglycerolemia (high TAGs) and hypercholesterolemia (high cholesterol)
Friedwald Equation
[LDL-C]=[total C]-([HDL-C]+[TAG:5])
What values are measured and used to calculate LDL-C in the Friedewald equation?
HDL-C and VLDL-TAGS are measured
Fredericton Classification
Way to classify hyperlipidemia which described their abnormal pattern of blood lipoproteins
Type I: Familial Hyperchylomicronemia
Rare disease characterized by high chylomicron levels after an overnight fast. Can be grouped into Type Ia (deficiency of LPL), type Ib (deficiency of apoC-II), and Type Ic (inhibitor protein for LPL). Onset in childhood, often abdominal cholic.
Eruptive Xanthomas
Occur in clusters on the skin of the trunk, buttock, or extremities. Result of familiar hyperchylomicronemia.
Type IIa: Familiar Hypercholesterolemia
Common disease characterized by high LDL levels and normal VLDL levels. Autosomal dominant disease with a defective LDL receptor. Adult onset with risk of coronary heart disease. Treated with statins and other drugs.
Type IIb: Familiar Combined Hyperlipidemia
Common diseased characterized by high LDL levels and also high VLDL levels. Overproduction of apoB-100 and VLDL, and defective clearance of LDL. Puberty onset, risk of coronary heart disease.
Type III: Dysbetalipoproteinemia
rare disease characterized by high remnant levels and abnormal beta-VLDL. High blood cholesterol levels mainly from IDL. Results from app E deficiency. Homozygous for the inefficient apoE-2 and lack the normal apoE-3. Xanthomas on the palms, elbows, and knees. Adult onset with accelerated atherosclerosis.
Type IV: Familial Hyperprebetalipoproteinemia
High VLDL due to a specific LPL deficiency or from overproduction of VLDL. High serum TAGs increases the risk of pancreatitis.
Type V: Familial Mixed Hypertriacylglycerolemia
High chylomicron microbe and high VLDL levels. Leads to elevated levels of both TAG-rich lipoproteins. Patients blood is characterized by a creamy layer on top and in addition to a turbid lower part due to high VLDL
What do statins competitively inhibit?
HMG CoA reductase
Treatments of Hyperlipidemia
Reception of free hepatic cholesterol or reduction of VLDL in the serum
Ezetimbie
Reduction of dietary uptake of cholesterol
