Exam 4: Mycotoxins

Question 1

Why is aflatoxin toxicosis primarily hepatic?

Answer 1

Toxicity due to metabolism of reactive metabolites that react with cellular macromolecules, DNA, RNA, and proteins leading to disruption of organ function

Question 2

Why is ochraotixn toxicosis is primarily renal?

Answer 2

Substrate for organic anion transporters in the kidney contribute to relatively high renal concentrations

Question 3

Why are ruminants relatively immune to ochratoxin-induced toxicosis?

Answer 3

Cleaved by rumen microbes to a non-toxic form

Question 4

What toxicities are associated with ergot toxicosis?

Answer 4

Cutaneous and gangrenous lesions of the tail and extremities
Hyperthermia and production loss
Reproductive failure
Convulsive or nervous form

Question 5

What is the mechanism of action of ergot toxicosis?

Answer 5

Complex pharmacological action that involves agonist and antagonist activity at tryptaminergic, dopaminergic, and alpha-adrenergic receptors
Serotonin, dopamine, norepinephirne
Vasoconstriction produced by agonist activities

Question 6

Why are trichothecenes also referred to as vomitoxin?

Answer 6

Clinical signs = vomiting at higher doses

Question 7

Toxicities of zearalenone are primarily associated with its activity as a weak ______?

Answer 7

estrogen

Question 8

What are the primary toxicoses associated with fumonisin?

Answer 8

Equine leukoencephalomalacia = neurotoxic, hepatic disease
Porcine pulmonary edema = dypnea, increased RR, cyanosis

Question 9

What is the name of the toxin associated with “slobber syndrome” and why does it cause slobbering?

Answer 9

Slaframine
Acts as a parasympathomimetic agent to stimulate exocrine and endocrine glands

Question 10

Why are dogs more likely to have toxicoses associated with penitrm A and roquefortine exposure?

Answer 10

Dogs more likely to scavenge in trash + be exposed to mold cheese, bread, walnuts, blue cheese

Question 11

What is another name for trichothecenes toxin?

Answer 11

Vomitoxin