Nitrate Flashcards
What factors favor plant nitrate accumulation?
Plant species Content and form of nitrogen in soil Soil conditions Decreased light Phenoxy acetic acid herbicides
What plant species have more nitrate accumulation?
Sweet clover
Alfalfa
Wheat
Corn
What soil conditions enhance nitrate uptake?
Rain/moisture Acid said (low pH) Low soil molybdenum low Sulfur low Phosphorus Low soil temp soil aeration and drought
What does decrease light cause to increase nitrate accumulation in plants?
decreases nitrate reductase
What part of the plant has more nitrate accumulation?
Stalk > Leaves > seeds/flower
Do younger or older plants contain more nitrate?
Young plants
What other plants accumulate nitrate?
Pigweed Oats Beets johnson grass, sudan grass, milo Corn, maize Lambs quarters Sweet clover Alfalfa Wheat Sunflower
What is sodium nitrite IV used for?
vasodilator
T/F. Nitrates are insoluble in water
False - they are soluble in water
T/F. Nitrate fertilizers are salty
True - makes them yummy!
How is nitrate converted to nitrite?
by nitrate reductase (microflora)
What is the LD50 for ruminants of nitrate?
0.5-1 g/kg
What species are most susceptible to nitrate poisoning?
Ruminants (rumen microflora)
What are horses very sensitive when it comes to nitrates?
IV nitrite
What species are resistant to nitrate?
Pigs
T/F. nitrate is more toxic than nitrite?
False - nitrite is 10x more toxic than nitrate
T/F. Adult animals are more susceptible to nitrate toxicity
False - young animals are
What disease state increases nitrate toxicity?
Anemia and methemoglobinemia
Nitrate is reduced by the rumen microflora to nitrite, which is converted to _______, which is converted to amino acids and microbial proteins
ammonia
The rate of conversion of nitrite to ammonia is _____ than the rate of conversion of nitrate to nitrite in ruminants
slower
What does the slower conversion of nitrate to ammonia in ruminants lead to?
rapid absorption and conversion of hemoglobin to methemoglobin
Death from anoxia (due to nitrate toxicity) occurs when methemoglobin reaches _____
80-90%
T/F. nitrate toxicity leads to direct vasoconstriction and hypertension
False, vasodilation and hypotension
What clinical signs will you see with nitrate toxicity?
Sudden death
Rapid breathing, restlessness, apprehension, dyspnea, weaknees, ataxia, sternal recumbency, cyanosis, terminal convulsions, abortion
What is the specimen of choice to diagnose for nitrate in animals that have died for several hours?
Ocular fluid
What test could you do to see if animals have been intoxicated with nitrate?
Diphenylamine test
How would you treat nitrate toxicity?
Methylene blue 1% IV for ruminants and monogastrics except cats as a reducing agent
Activated charcoal
Ruminal lavage with cold water, antibiotics to inhibit rumen microflora and nitrate reductase
