Chapter 18- Lipid III Plasma Lipoproteins

Question 1

Principle TG carriers are

Answer 1

Chylomicrons and VLDL

Question 2

List the least dense lipoprotein to most dense

Answer 2

Chylomicron -> VLDL -> IDL -> LDL -> HDL2 -> HDL3 -> Lp(a)

Question 3

regulation of hepatic lipase

Answer 3

+ to androgens, - to increase level of estrogens

Question 4

Cholesteryl esters are transferred to VLDL and LDL via?

Answer 4

Apo D and cholesteryl ester transfer protein (CETP)

Question 5

a defect in the ABC1 transporter is associated with what diseases?

Answer 5

Tangier’s disease, CF, early onset macular degeneration, adrenoleuko dystrophy, zellweger syndrome, progressive familial intrahepatic cholestasis

Question 6

Apo A-II on larger HDL particles does what?

Answer 6

inhibits hydrolysis of HDL-TG and PL by hepatic lipase

Question 7

Lipoproteins present in excess for hyperlipoproteinemia phenotype I?

Answer 7

Chylomicrons

Question 8

Lipoproteins present in excess for hyperlipoproteinemia phenotype IIa?

Answer 8

LDL

Question 9

Lipoproteins present in excess for hyperlipoproteinemia phenotype IIb?

Answer 9

LDL + VLDL

Question 10

Lipoproteins present in excess for hyperlipoproteinemia phenotype III?

Answer 10

beta-VLDL

Question 11

Lipoproteins present in excess for hyperlipoproteinemia phenotype IV?

Answer 11

VLDL

Question 12

Lipoproteins present in excess for hyperlipoproteinemia phenotype V

Answer 12

Chylomicrons + VLDL

Question 13

Abetalipoproteinemia characterized by a defect in

Answer 13

no chylomicrons, VLDL, or LDL formed d/t defect in the loading of Apo B with lipid

Question 14

Familial alpha-lipoprotein deficiency includes

Answer 14

Tangier’s disease, Fish-eye disease, Apo AI deficiencies

Question 15

Familial alpha-lipoprotein deficiency characterized by

Answer 15

low or near absent HDL

Question 16

Familial lipoprotein lipase deficiency type 1 characterized by

Answer 16

hypertriacylglycerolemia d/t deficient LPL or Apo C-II deficiency causing inactive LPL

Question 17

Familial hypercholesterolemia type IIa characterized by

Answer 17

defective LDL receptors or mutation in ligand region of Apo B-100

Question 18

Familial hyperlipoproteinemia type III characterized by

Answer 18

deficiency of remnant clearance by liver d/t abnormal Apo E. its lack isoform E3 and E4 and only have E2 which does not react with receptor

Question 19

Familial hyperalphalipoproteinemia characterized by

Answer 19

increased concentrations of HDL

Question 20

Familial hypertriacylglycerolemia (type IV) characterized by

Answer 20

overproduction of VLDL also. with glucose intolerance

Question 21

Hepatic lipase deficiency characterized by

Answer 21

deficiency of the enzyme leads to accum. of large TAG rich HDL and VLDL remnants

Question 22

Familial LCAT deficiency characterized by

Answer 22

absence of LCAT results in block of reverse cholesterol transport. HDL remains nascent disks unable to take up cholesterol

Question 23

Familial lipoprotein(a) excess characterized by

Answer 23

Lp(a) consists of 1 mol of LDL attached to 1 mol apo(a). Apo(a) shows structural homologies to plasminogen

Question 24

plasma LDL cholesterol level can be calculated by

Answer 24

total cholesterol - (VLDL cholest. + HDL cholest.)
or
total cholesterol - (TG/5 + HDL cholest.)

after 12-24 hour fast

Question 25

Cholestyramine & colestipol mechanism:

Answer 25

bile acid sequestant - nonabsorbable resins, interrupt enterohepatic circulation of bile acids

Question 26

Nicotinic acid mechanism:

Answer 26

reduce VLDL & LDL by inhibiting hepatic secretion of VLDL & by suppressing mobilization of FA

Question 27

Clofibrate & gemfibrozil mechanism:

Answer 27

fibric acid derivatives - promote rapid turnover of VLDL by activating lipoprotein lipase, gemfibrozil inhibit VLDL secretion

Question 28

Probucol mechanism:

Answer 28

reduce plasma cholesterol level but no effect on TG, act via blockage of intestinal cholesterol transport, HDL cholesterol levels are reduced by this drug

Question 29

Statins mechanism:

Answer 29

competitive inhibitor of HMG-CoA reductase - inhibit the regulatory step in biosynthesis of cholesterol, lower serum cholesterol & LDL cholesterol by inhibition of hepatic cholesterol synthesis, by up-regulating LDL receptor activity