Toxicology

Question 1

How is Lathyrus hirsutus, the “flat pea,” toxic to horses? What clinical signs are seen?

Answer 1

In ruminants, the toxin 2,4-diaminobutyric acid was shown to inhibit ornithine transcarbamylase, which is needed for urea detoxification.

In horses, it is likely that the toxin targets central pattern generators located in cervical and lumbar intumescens. CPGs control locomotion and coordination of gait is maintained by rhythmic cyclical excitation and inhibition of flexor and extensor muscles within and between limbs.

The horses in this study showed neurologic deficits and gait abnormalities, i.e. stilted gait

10.1111/jvim.12515

Question 2

What portion of the the common European sycamore maple tree contains the most hypoglycin A?

A. Bark
B. Leaves
C. Seeds
D. Sprouts

Answer 2

The seeds contained the most hypoglycin A. The specific tree, Acer pseudoplatanus was the species that contained the most.

10.1111/jvim.13927

Question 3

How does toxicity of hypoglycin A cause its clinical affects?

Answer 3

Hypoglycin A is metabolized in the liver and irreversibly binds to multiple acyl CoA. These are needed for metabolism of short and medium chain FAs and branched chain AAs. Accumulation of fat esters can damage muscle cell membranes and energy deficiency from an inability to metabolize fats.

10.1111/jvim.13927