Liver with brownish pigment – lipofuscin (seen on gross pic; can also be hemosiderin, bilirubin, etc;
therefore need to have a case with the gross pic); end products of free radical damage are lipofuscin
b/c certain things are not digestible (include lipids).
A. Definition of free radical – compound with unpaired electron that is out of orbit, therefore it’s
very unstable and it will damage things.
B. Types of Free Radicals:
1. Oxygen: We are breathing O , and O can give free radicals. If give a person 50% O for a
2 2 2
period of time, will get superoxide free radicals, which lead to reperfusion injury, esp after giving
tPA when trying to rid a damaged thrombus. Oxygentated blood goes back into the damaged
cardiac muscle=reperfusion injury. Kids with resp distress syndrome can get free radical injury
and go blind b/c they destroy the retina – called retinopathy prematurity; also leads to
bronchopulmonary dysplasia, which leads to damage in the lungs and a crippling lung disease.
2. Water in tissues converted to hydroxyl free radicals, leading to mutations in tissues.
Complication of radiation therapy is CANCER (MC cancer from radiation is leukemia, due to
hydroxyl free radicals). Fe2+ produces hydroxyl free radicals b/c of the fenton rxn. This is what
makes Fe overload diseases so dangerous, b/c wherever Fe is overloaded, leads to hydroxyl free
radicals which will damage that tissue (therefore, in liver leads to cirrhosis, in heart leads to
restrictive cardiomyopathy, in pancreas leads to failure, and malabsorption, along with
3. Tylenol (aka acetaminophen):
MCC drug induced fulminant hepatitis b/c free radicals (esp targets the liver, but also targets