Snake Venoms and Cardiotoxins Lecture Notes

Flashcards covering the definitions, mechanisms, and specific examples from the lecture on veterinary cellular biology regarding snake venoms and cardiotoxins.

Poisons

Toxic substances produced by animals that cause toxicity when they are ingested, inhaled, or absorbed.

Venoms

Toxic substances produced by animals that cause toxicity when they are injected via a bite or sting.

3-Finger toxins ($3FTx$)

Non-enzymatic proteins with a highly conserved secondary structure that act as potent neurotoxins or cardiotoxins; specifically, they perforate cardiac myocytes to allow rapid entry of $Ca^{2+}$.

Phospholipase-A2 ($PLA2$)

An enzyme in snake venom that hydrolyzes cell membrane phospholipids, effectively chewing holes in the myocyte membrane and leading to cell death.

Neurotoxic

A type of toxic property in snake venom that affects the neuronal system.

Myotoxic

A type of toxic property in snake venom that affects cardiac and/or skeletal muscle.

Hemotoxic

A type of toxic property in snake venom that affects red blood cells.

Cardiotoxin

A chemical or protein that can disrupt the electrical and/or contractile function of the heart, potentially causing arrhythmias or heart failure.

Monensin

An antibiotic ionophore originally isolated from $\text{Streptomyces cinnamonensis}$ used as a feed additive (Rumensin®) and anti-coccidiosis agent.

Ionophore

A chemical that binds and transports ions across membranes; monensin specifically transports monovalent cations, especially $Na^+$.

Na+/Ca2+ Exchanger ($NCX$)

A transport mechanism that the cell uses to remove excess $Na^+$ in exchange for $Ca^{2+}$; it is the pathway by which monensin causes toxic $Ca^{2+}$ overload.

Horse $LD_{50}$ for Monensin

The lethal dose for horses, which is highly sensitive to monensin at $2-3\,mg/kg$, whereas cattle can tolerate higher doses.

$$Crotalus\,viridis$$

The scientific name for the rattlesnake species involved in the case study of horse envenomation.

Eimeria

The family of coccidial protozoans targeted and killed by monensin when used as an anti-parasite agent in livestock.