Biomaterial Database

Effect of thyroid dysfunction on high-density lipoprotein subfraction metabolism: roles of hepatic lipase and cholesteryl ester transfer protein. 1998

K C Tan, and S W Shiu, and A W Kung

Department of Medicine, University of Hong Kong, Hong Kong.

To investigate the effect of thyroid dysfunction on high-density lipoprotein (HDL) metabolism, we measured HDL subfractions, apolipoprotein A-I containing particles (LpA-I and LpA-I:A-II), and the activities of enzymes involved in the remodeling and metabolism of HDL [namely hepatic lipase (HL), lipoprotein lipase, and cholesteryl ester transfer protein (CETP)] in 18 hyperthyroid and 17 hypothyroid patients before and after treatment. HDL was subfractionated by density gradient ultracentrifugation, and LpA-I was analyzed by electroimmunodiffusion. The major changes were found in the HDL2 subfraction and in LpA-I particles. HDL2-C and LpA-I were reduced in hyperthyroidism (P < 0.01, P < 0.05, respectively) and increased in hypothyroidism (both P < 0.05) compared with their respective euthyroid matched controls. Changes in HDL2-cholesterol were reversed after treatment in both hyper- and hypothyroid patients, and LpA-I also decreased in the hypothyroid patients after treatment. HL (P < 0.05) and CETP activities (P < 0.05) were elevated in hyperthyroidism and reduced in hypothyroidism (P < 0.05, P < 0.01 respectively) and both were related to free T4 levels. The changes in HDL2-C and LpA-I correlated significantly with changes in HL after treatment but not with CETP or lipoprotein lipase. In summary, HDL metabolism was altered in thyroid dysfunction, and the effect of thyroid hormone on HDL was mediated mainly via its effect on HL activity.

UI	MeSH Term	Description	Entries
D007037	Hypothyroidism	A syndrome that results from abnormally low secretion of THYROID HORMONES from the THYROID GLAND, leading to a decrease in BASAL METABOLIC RATE. In its most severe form, there is accumulation of MUCOPOLYSACCHARIDES in the SKIN and EDEMA, known as MYXEDEMA. It may be primary or secondary due to other pituitary disease, or hypothalamic dysfunction.	Central Hypothyroidism,Primary Hypothyroidism,Secondary Hypothyroidism,TSH Deficiency,Thyroid-Stimulating Hormone Deficiency,Central Hypothyroidisms,Deficiency, TSH,Deficiency, Thyroid-Stimulating Hormone,Hormone Deficiency, Thyroid-Stimulating,Hypothyroidism, Central,Hypothyroidism, Primary,Hypothyroidism, Secondary,Hypothyroidisms,Primary Hypothyroidisms,Secondary Hypothyroidisms,TSH Deficiencies,Thyroid Stimulating Hormone Deficiency,Thyroid-Stimulating Hormone Deficiencies
D008049	Lipase	An enzyme of the hydrolase class that catalyzes the reaction of triacylglycerol and water to yield diacylglycerol and a fatty acid anion. It is produced by glands on the tongue and by the pancreas and initiates the digestion of dietary fats. (From Dorland, 27th ed) EC 3.1.1.3.	Triacylglycerol Lipase,Tributyrinase,Triglyceride Lipase,Acid Lipase,Acid Lipase A,Acid Lipase B,Acid Lipase I,Acid Lipase II,Exolipase,Monoester Lipase,Triacylglycerol Hydrolase,Triglyceridase,Triolean Hydrolase,Hydrolase, Triacylglycerol,Hydrolase, Triolean,Lipase A, Acid,Lipase B, Acid,Lipase I, Acid,Lipase II, Acid,Lipase, Acid,Lipase, Monoester,Lipase, Triglyceride
D008075	Lipoproteins, HDL	A class of lipoproteins of small size (4-13 nm) and dense (greater than 1.063 g/ml) particles. HDL lipoproteins, synthesized in the liver without a lipid core, accumulate cholesterol esters from peripheral tissues and transport them to the liver for re-utilization or elimination from the body (the reverse cholesterol transport). Their major protein component is APOLIPOPROTEIN A-I. HDL also shuttle APOLIPOPROTEINS C and APOLIPOPROTEINS E to and from triglyceride-rich lipoproteins during their catabolism. HDL plasma level has been inversely correlated with the risk of cardiovascular diseases.	High Density Lipoprotein,High-Density Lipoprotein,High-Density Lipoproteins,alpha-Lipoprotein,alpha-Lipoproteins,Heavy Lipoproteins,alpha-1 Lipoprotein,Density Lipoprotein, High,HDL Lipoproteins,High Density Lipoproteins,Lipoprotein, High Density,Lipoprotein, High-Density,Lipoproteins, Heavy,Lipoproteins, High-Density,alpha Lipoprotein,alpha Lipoproteins
D008076	Cholesterol, HDL	Cholesterol which is contained in or bound to high-density lipoproteins (HDL), including CHOLESTEROL ESTERS and free cholesterol.	High Density Lipoprotein Cholesterol,Cholesterol, HDL2,Cholesterol, HDL3,HDL Cholesterol,HDL(2) Cholesterol,HDL(3) Cholesterol,HDL2 Cholesterol,HDL3 Cholesterol,alpha-Lipoprotein Cholesterol,Cholesterol, alpha-Lipoprotein,alpha Lipoprotein Cholesterol
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008297	Male		Males
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D002499	Centrifugation, Density Gradient	Separation of particles according to density by employing a gradient of varying densities. At equilibrium each particle settles in the gradient at a point equal to its density. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Centrifugations, Density Gradient,Density Gradient Centrifugation,Density Gradient Centrifugations,Gradient Centrifugation, Density,Gradient Centrifugations, Density
D005260	Female		Females
D006023	Glycoproteins	Conjugated protein-carbohydrate compounds including MUCINS; mucoid, and AMYLOID glycoproteins.	C-Glycosylated Proteins,Glycosylated Protein,Glycosylated Proteins,N-Glycosylated Proteins,O-Glycosylated Proteins,Glycoprotein,Neoglycoproteins,Protein, Glycosylated,Proteins, C-Glycosylated,Proteins, Glycosylated,Proteins, N-Glycosylated,Proteins, O-Glycosylated