Metabolism XIV

Question 1

What is the function of IDL?

Answer 1

To deliver triglycerides and cholesterol to the liver (p.116)

Question 2

What is the function of LDL?

Answer 2

To deliver hepatic cholesterol to peripheral tissues (p.116)

Question 3

What is the function of HDL?

Answer 3

To mediate the reverse transport of cholesterol from the periphery to the liver. It acts as a repository for ApoC and apoE (which are needed for chylomicron and VLDL metabolism)

Question 4

What secretes VLDL?

Answer 4

The liver (p.116)

Question 5

How is IDL cholesterol formed?

Answer 5

Through the degradation of VLDL (p.116)

Question 6

How is LDL cholesterol formed?

Answer 6

By hepatic lipase modification of IDL in the peripheral tissue (p.116)

Question 7

How is LDL taken up in target tissues?

Answer 7

By receptor mediated endocytosis (p.116)

Question 8

What secretes HDL?

Answer 8

Both the liver and the intestines (p.116)

Question 9

What lipids are elevated in Type-I-Hyper-chylomicronemia?

Answer 9

Chylomicrons, TG, cholesterol (p116)

Question 10

What lipids are elevated in Type-IIa familial hyper-cholesterolemia?

Answer 10

LDL, cholesterol (p.116)

Question 11

What lipids are elevated in Type-IV-Hyper-triglyceridemia?

Answer 11

VLDL, TG (p.116)

Question 12

Name the three familial dyslipidemias.

Answer 12

Type I- hyper-chylomicronemia; type IIa- familial hyper-cholesterolemia; type IV- hyper-triglyceridemia (p.116)

Question 13

What is the pathophysiology of Type-I-Hyper-chylomicronemia?

Answer 13

Lipoprotein lipase deficiency or altered apolipoprotein C-II (p.116)

Question 14

What is the pathophysiology of Type-IIa familial hyper-cholesterolemia?

Answer 14

Absent of decreased LDL receptors (p.116)

Question 15

What is the pathophysiology of Type-IV-Hyper-triglyceridemia?

Answer 15

Hepatic overproduction of VLDL (p.116)

Question 16

What is the genetic inheritance of Type-I-Hyper-chylomicronemia?

Answer 16

Autosomal recessive (p.116)

Question 17

What is the genetic inheritance of Type-IIa familial hyper-cholesterolemia?

Answer 17

Autosomal dominant (p.116)

Question 18

What is the genetic inheritance of Type-IV-Hyper-triglyceridemia?

Answer 18

Autosomal dominant (p.116)

Question 19

What are the symptoms of Type-I-Hyper-chylomicronemia?

Answer 19

Pancreatitis, hepatosplenomeagly, eruptive/pruritic xanthomas. No increased risk for atherosclerosis (p.116)

Question 20

What are the symptoms of Type-IIa familial hyper-cholesterolemia?

Answer 20

Accelerated atherosclerosis, tendon (Achilles) xanthomas, corneal arcus (p.116)

Question 21

What are the symptoms of Type-IV-Hyper-triglyceridemia?

Answer 21

Pancreatitis (p.116)

Question 22

Describe the genetic mutation and inheritance of Abetalipoproteinemia.

Answer 22

An autosomal recessive mutation in microsomal triglyceride transfer protein (MTP gene) (p.116)

Question 23

What is the pathophysiology of abetalipoproteinemia?

Answer 23

Decreased B-48 and B-100 due to genetic mutatation of the microsomal triglyceride transfer protein (MTP gene). This causes decreased chylomicron and VLDL synthesis and secretion (p.116)

Question 24

What does an intestinal biopsy show in a patient with abetalipoproteinemia?

Answer 24

Lipid accumulation within erythrocytes due to inability to export absorbed lipids as chylomicrons (p.116)

Question 25

What are the clinical findings in a patient with abetalipoproteinemia?

Answer 25

Symptoms usually detected within the first few months of life. Findings include failure to thrive, steatorrhea, acanthocytosis, ataxia, night blindness (p.116)