CC: HMPS, RBC Oxidation and Anemia Flashcards
What happens to RBCs in the lungs with respect to oxidation?
RBCs are exposed to high amounts of Free Radical in the lungs as well as the arterial system.
What two parts of the RBC are affected by oxidative damage?
Membrane and Hemoglobin (pretty much all that they’re made up of)
What happens when oxygen is exposed to fatty acids (fats in general)?
Hydrogen Peroxide formation.
What happens to oxygen when it receives an extra electron?
Superoxide anion
What happens when H2O2 is combined with Superoxide anion?
Hydroxyl Radical - really bad ass
What happens when Fe++ (normal hemoglobin iron) is exposed to H2O2?
Fe+++ (methemoglobin) and hydroxyl radical formation.
Methemoglobin tends to precipitate too ==> Heinz Bodies
What are Heinz Bodies?
precipitated Methemoglobin in RBCs
How can you reverse some of the damage from methemoglobin (Fe+++) damage?
Methemoglobin (Fe+++) reductase use NADH to get back to Hemoglobin (Fe++)
What is the typical result of damage to RBCs?
Hemolytic Anemia
What causes Heinz Body formation specifically in Horses? (other things do too)
Red Maple Leaves
What do onions and garlic do to an animal?
Heinz Body formation in Horses, Cows, Cats, Dogs and Primates (yes us too!)
Why should you not give acetaminophen to cats? (with respect to this topic)
Heinz Body formation –> hemolytic anemia
What does propylene glycol do to cats? Why would this be an issue in their diet?
Heinz Body formation –> hemolytic anemia
It was used as a humectant to keep food moist but was banned from cat foods by the FDA in 1996.
What does superoxide dismutase do?
It takes the oxygen radical and makes H2O2 and Oxygen.
How does the body protect against H2O2?
CATALASE takes H2O2 and makes oxygen and water.
How does Glutathione Peroxidase protect the body against oxidative damage?
It can perform 2 reactions:
H2O2 + Glutathione –> Water and GSSG
Lipid-OOH (oxidative damage to lipid) + Glutathione –> Lipid-OH (not perfect, but less damaged) + GSSG + Water
How does Glutathione Reductase protect the body against oxidative damage?
using NADPH it will break GSSG back to GSH/Glutathione so it (Glutahione) can continue to protect against oxidative damage via Glutathione Peroxidase.
This uses a cofactor FAD which is different from the FAD we know and love in TCA Cycle/ETC.
How is Glutathione (GSH) made? Where does it come from?
Glutamate + Cysteine + ATP –> gamma-Glutamylcysteine + Glycine + ATP –> Glutathione.
It now has a free sulfhydryl group which is used in antioxidant defense system.
What would you expect from a Glucose-6-Phosphate Dehydrogenase deficiency?
It is the first enzyme in HMPS: can’t make NADPH!!!
Cannot restore Glutathione back to its original reduced state –> messes up antioxidant defense system ==> HEMOLYTIC ANEMIA
What seemingly harmless drugs cause G-6-PDH deficiency? (Eng question)
antimalarials, antipyretics, sulfa antibiotics
These drugs work on sulfhydryl/disulfide bonds.
What’s up with rabbits and this enzyme G-6-PDH?
They have LOW levels to begin with.
Acetylphenylhydrazine and Primaquine Phosphate are BAD for rabbits
What inhibits G-6-PDH in sheep liver?
Penicillin, Cefazolin, Sulbactam, amikacine
How come Fava Beans are bad?
Animals deficient in G-6-PDH are prone to fava bean poisoning
What is the potential effect on PCV hematocrit with a thiamine/B1 deficiency?
Lowers it –> Hemolytic anemia = less RBCs = lower PCV
