05b Liver, GB, pancreas biochem

Question 0

Bilivirdin reductase

Answer 0

NADP or NADPH dependent enzyme in macrophages that changes Biliverdin to bilirubin

Question 1

Heme oxygenase

Answer 1

NADPH dependent cleaving of heme into biliverdin

Question 2

UGTA1

Answer 2

Udp glucuronyl transferase that conjugates glucuronic acid to bilirubin so that it can be secreted into aqueous environment

Question 3

MOAT

Answer 3

Multiorganic anion transporter-

ATP dependent ransporter that secretes conjugated bilirubin into the bile cannaliculi

Question 4

Neonatal Jaundice

Answer 4

• Low UGT1A1at birth leads to increased indirect bilirubin in blood stream
• Can cause Kernicterus- bilirubin encephalopathy

Tx: phototherapy to isomerize bilirubin

Question 5

Crigler - Najjar

Answer 5

UGT1A1 deficiency causing bilirubin buildup

• Absence –> Type I, causes Kernincterus and brain damage, 30 year life expectancy with need for phototherapy and perhaps liver transplant
• Low—> Type 2 called “gilberts” relatively common and benign

Question 6

Dubin Johnson syndrome

Answer 6

MOAT Defect

• Black liver due to increased conjugated bilirubinemia,
• usually benign and atosomal recessive
• can have 20mg/dl bilirubin

Question 7

Bile acids

Answer 7

• OH added to cholesterol, Terminal siddechain is carboxylated
• more water soluble than cholesterol

Question 8

Primary bile acids

Answer 8

Cholic acid, Chenodeoxycholic acid

Question 9

Secondary bile acids

Answer 9

Deoxycholic acid

Lithocolic acid

Question 10

Bile salts

Answer 10

Deoxycholic acid+ Glycine conjugation

Lithocholic acidd + Taurine