Pigment! Flashcards
True or false? Pigments can be both incidental or pathological findings.
True
What are pigments?
Substances the accumulate in cells that cause discoloration to the tissue
Name 4 examples of endogenous pigments that arise from normal body compounds
- lipofuscin
- melanin
- hemosiderin
- bilirubin
Name 2 examples exogenous pigments that arise from materials not natural to the body
- tattoo ink
- carbon
What pigment is known as the “wear and tear” pigment?
Lipofuscin
What is lipofuscin the result of?
Long-term, excessive peroxidation of unsaturated FA by oxygen free radicals.
What is lipofuscin?
Yellow-brown pigmented, cytoplasmic granules composed of lipid residues.
True or false? Lipofuscin is usually pathogenic in aged animals.
False, usually incidental and non-pathogenic in aged animals.
What is “brown dog gut” an example of?
Lipofuscinosis
-rare incidental finding in aged dogs, often associated with Vitamin E/Se deficiency.
What is Melanosis?
Condition where melanin is found naturally in abnormal locations (incidental findings)
What pigment is located in what location in black-faced animals?
Gray/black melanosis of the forebrain meninges.
What are iron storage proteins composed of apoferritin molecules (protein) plus iron (III)?
Ferritins
What is an iron storage complex (ferritin aggregate) within cells, especially macrophages, hepatocytes, renal tubular epithelium, bone marrow and spleen red pulp.
Hemosiderin
What is hemosiderosis?
Accumulation of hemosiderin in tissue causes yellow (golden)/brown discoloration. Hemosiderin in generally non-toxic. Can be a diagnostic “stepping stone”
What can hemosiderin accumulate in?
-macrophages and hepatocytes
