One milligram is enough to kill 10 people. Why don't poisonous animals die with their toxins?

Poison may be a means for some animals to defend themselves, but the success of this defensive plan is conditional on the poison cooks not tasting from these organisms their poison.

How does that happen?

For example, poison frogs and some birds are filled with a toxin called batrachotoxin, which kills prey by disrupting proteins in the membranes of neurons that control their nervous activity;

The toxin inhibits nerve impulses by binding to the sodium channels that control these impulses.

The team studied sodium channels isolated from venomous 'pathoey' birds (Yurik Alert).

A dangerous neurotoxin

The poison "patrachotoxin" is one of the most dangerous neurotoxins, and this alkaline toxic substance is found in some species of beetles, as well as in frogs that inhabit the tropical forests of Colombia, and in the birds of "Pitohui" in Papua New Guinea in northern Australia.

The golden poisonous frog Phyllobates terribilis contains approximately one milligram of batrachotoxin in the skin glands.

This small amount is enough to kill about 10 people or more.

But how does this extreme toxicity not affect the sodium channels found in poisonous frogs?

Scientists have long believed that organisms containing the toxins "patrachotoxin" introduced some mutations to the proteins of their nerve membranes, which in turn prevents these toxins from binding to them.

The golden poisonous frog contains membrane proteins that are sensitive and non-resistant to batrachotoxin (Pixabay).

different mechanism

However, a recent study was published in the Journal of General Physiology on August 5, and was carried out by scientists from the University of California, San Francisco, and Stanford University. University), from the California Academy of Sciences;

She did not find a trace of such membranous mutations in the golden poisonous frog.

According to the press release published by the "Eurek Alert" website;

Daniel Minor, a professor at the University of California, San Francisco, says that his team "studyed sodium channels in two types of poisonous frogs, one containing batrachotoxin, the other a similar poison, and in another type of "pathoey".

The team isolated sodium channels from golden frogs and "pathoe" birds, and the study found no role for mutations that are resistant to the batrachotoxin toxin.

Contrary to what was indicated by a previous study, this study showed that the golden poisonous frog contains membrane proteins sensitive and non-resistant to "batrachotoxin".

For example, sodium channels isolated from the golden poison frog showed 10 times more sensitivity to batrachotoxin than their wild counterparts.

Thus, intrinsic resistance to toxins is not a matter of sodium channel mutations in these organisms.

How do these organisms avoid their own toxins?

The transport and concentration of toxins within the skin is critical in poisonous frogs (pixabay).

Absorbent Sponge Proteins

Here, the team thought that there was some mechanism in the way of batrachotoxin being able to target sodium channels.

The team found that a protein known as Saxiphilin acts as a sponge absorbent that can absorb saxitoxin, another neurotoxin similar to batrachotoxin.

However, the study has not yet identified any spongy proteins that can absorb the batrachotoxin poison and prevent its binding to sodium channels in poisonous golden frogs and in "pathoei" birds, which is what Minor and his team intend to study in the future.

Minor concludes that this study "not only provides a framework of knowledge about how to combat toxins, but may also help in understanding the pathways that help transport toxins and their concentration in key defensive organs such as the skin."