LFTs and cases Flashcards
Enzyme-catalysed processes within cells that extract energy from nutrient molecules and use that energy to construct cellular components is ___?
intermediary metabolism
which are the most abundant proteins syntheissed in the liver?
- enzymes
- protein binding
- nucleic acid binding
- transporters
- signal transduction
- structural
what are some reactions and components involved in xenobiotic metabolism?
- Chemical Modification:
P450 Enzyme System
Acetylation / de-acetylation
Oxidation / Reduction - Conjugation
glucuronate
sulphate - Excretion
what components due we look at to assess ACUTE LIFVER DYSFUNCTION?
INR
PT
Which hormones are metabolised in liver?
give details of the reaction?
Vitamin D:
hydroxylation - 25OHD3 -> 1,25OHD3
Steroid Hormone :
conjugation
excretion
Peptide Hormone:
catabolism
List some constituents of bile.
list some functions of bile?
constituents: Water Bile salts/acids Bilirubin Phospholipids Cholesterol Proteins Drugs and Metabolites
functions:
Excretion - of waste products eg bilirubin into faeces
Micelle formation
Digestion - of fats and fat soluble vitamins
how is bilirubin created?
how is it transported around the body?
- Red cells are broken down releasing heme, iron and globin
- The heme then goes on to form bilirubin
- Bilirubin is then bound to albumin in the plasma
- This unconjugated bilirubin goes to the liver and becomes glucuronidated
- The conjugated bilirubin is released into the bile
describe the Reticuloendothelial (immune) Function of the liver?
1.Erythropoesis
- Kupffer Cells:
a phagocytic cell
which forms the lining of the sinusoids of the liver and is involved in the breakdown of red blood cells.
are adhesive to their endothelial cells which make up the blood vessel walls.
Clearance of infection and LPS
Antigen presentation
Immune modulation
-cytokines etc.
list some Serum markers of liver cell damage?
ALT
AST
ALP
GGT
list some markers of Synthetic function?
Albumin
Pro-thrombin time (PT)
Bilirubin
describe the hepatic archictecture?
made of subunits called lobules - hexagonal structure
- central vein in middle
- hepatic artery, portal vein and bile duct in corners of hexagon (portal triad)
- sinusoids flowing from central vein to portal arteriole/vein
interlobular veins connected to hepatic vein
nutmeg appearance
describe heaptic sinusoids
fenestrated endothelial lining
also lined by kupffer cells
what are the functoins of AST and ALT
where are they found?
enzymes contained within cytoplasm of hepatocytes
“catalyzes the transfer of the alpha-amino groups of alanine and aspartate, respectively, to the alpha-keto group of ketoglutarate, which results in the formation of pyruvate and oxaloacetate…..”
AST: ALT ratio >2.0, suggestive of —-? why?
alcoholic liver disease
because AST rises more
In absence of alcohol AST:ALT ratio >0.8 suggest ___?
? advanced fibrosis or cirrhosis
which hormone :
catalyzes the transfer of the gamma-glutamyl group from gamma-glutamyl peptides such as glutathione to other peptides and to L-amino acids…”
GGT
Where is ggt found?
found in liver, kidney, pancreas, spleen, heart, brain, seminal vesicles
in liver found in hepatocytes and epithelium of small bile ducts
when is GGT elevated?
elevated in chronic alcohol use
also raised in bile duct disease and hepatic metastasis
which hormone :
a group of enzymes that catalyze the hydrolysis of a large number of organic phosphate esters at an alkaline pH
ALP
where is ALP located ?
liver version - located in sinusoidal and canalicular membranes
other sources bone, small intestine, kidney, WBC’s, placenta etc