Cell Injury and Biomarkers Flashcards
hypertrophy
cells get larger but there are not more cells
atrophy
reversible decrease in muscle mass
can be reversed through use and exercise
can hyperplasia be reversible?
yes
hyperplasia
increase in the number of cells
proliferation
cytoplasmic eosinophilic
early cell injury due to RNA spilling into cytoplasm
necrosis
cell membrane is not intact
loss of nuclei
loss of distinguishing cell features (ex: microvilli)
blebs
irregular bulge in the plasma membrane due to membrane breaking down
can membrane blebbing be reversed?
yes
myelin figures
whirls and clumps of membrane
phospholipid dense
seen in stressed / dying cells
metaplasia
normal epithelium being replaced by different cells
example of metaplasia
Barret’s esophagous
troponin I
specific for cardiac muscle
peak 1 day after MI
lactate dehydrogenase
converts lactate to pyruvate in anaerobic glycolysis
cytoplasmic enzyme
does an increase in troponin I always indicate an MI?
no
can indicate any pathology that causes cardiac cell death
What does lactate dehydrogenase indicate?
broad cell death, found in many tissues
When does LD peak following an MI?
~3 days
AST function
convert aspartate to oxaloactate and glutamate
Where is AST found?
in many tissues including heart and liver
AST and alcohol abuse
liver makes more AST when metabolizing alcohol
leads to increased ratio of AST : ALT
When does AST peak after MI?
~ 2 days
Rank when the biomarkers for MI peak
1) CKMB
2) Troponin I and troponin T (1 day)
3) AST (2 days)
4) LDH (3 days)
troponin T
more general troponin than troponin I (specific for cardiac)
ALT
found in the liver
converts alanine to pyruvate
shows hepatocyte damage
where is ALT expressed besides the liver? when can ALT be increased in this tissue?
skeletal muscle and can be increased in response to vigorous exercise
Where is amylase found?
pancrease and salivary gland
amylase function
hydrolyze a-1,4 linkages in starch
*breaks down complex carbs
What does amylase indicate?
pancreatitis
Lipase function
hydrolyze fat (triacylglycerol)
What does lipase indicate?
presence in blood indicates pancreatitis
what does an increase in unconjugated bilirubin indicate?
pre-liver damage
what does an increase in total bilirubin indicate?
post-liver or biliary tree damage
bilirubin general pathway
produced in the tissues and conjugated in the liver
where is unconjugated bilirubin found?
the blood
AlkPhos function
breaks down pyrophosphate to 2-phosphates
What does increased AlkPhos indicate?
bile duct or bone disorders
If AlkPhos is elevated, what can we check to determine between bile duct and bone disorder?
GGT
GGT function (general)
important in biliary excretion of substances such as drugs
uses glutathione to break down drugs
What does elevated INR indicate?
increased bleeding time and lack of clotting factors
increased AST and ALT indicates
destruction of hepatocytes
parenchymal liver disease
increased conjugated bilirubin w/ alkphos and ggt increase indicates …
obstructive bile duct disease
examples of obstructive bile duct disease
gallstone, pancreatic head tumor
how can gallstones elevate liver and pancreas enzymes?
gallstones can block the ampulla of VAter
leads to backup of bile into the common hepatic duct (liver) and pancreatic duct (pancreas)
ampulla of Vater
where the common bile duct meets the duodenum
selective vulnerability of liver to acetamenophin
metabolism of drug by cytochrome P450 makes drug present in the liver to become toxic??
how is most acetaminophen eliminated?
renally
P450 oxidation of acetaminophen
oxidizes the remaining acetaminophen which creates reactive metabolite NAPQI
too much NAPQI can be toxic
