For people who are allergic to cats, wherever they are can become a toxic area. Studies of the cute mammal show that this might not be a fluke of nature – cats are really trying to scare us away
A study of the world's only known example of a venomous primate found surprising similarities between a key protein in its axillary glands and an allergen found in cats, suggesting that if one of them evolved into a defensive weapon, then the other might as well.
This discovery not only places feline allergy in a new context, but could lead to treatment for those suffering from unpleasant contact with any animal.
Slow lorises (Nycticebus sp.) Are several primate species commonly found in the wild in South and Southeast Asia. Looking at them, it seems that it was invented in a toy workshop for toddlers.
But don't let looks fool you. The lorises have rows of tiny, razor-sharp teeth in their mouths, which are used both to tear small prey apart and keep predators and competitors alike at bay.
As if a bite wasn't enough, when threatened, the furry monsters raise their arms and lick the glands hidden in their armpits, filling their saliva with a rich array of compounds, fine-tuned to turn the tiny cut into dead flesh.
“Usually slow lorises use their venom in intraspecific competition, causing very dangerous wounds,” says biologist Brian Fry of the University of Queensland in Australia.
“But when people are bitten, the person has symptoms like they are going into an allergic shock.”
These symptoms can include shortness of breath, severe pain, and, in worse cases, anaphylactic shock.
The secretions responsible for the toxic effects of an animal bite are known to include more than two hundred aromatic compounds, many of which have already been characterized.
But there are a bunch of proteins among them that still present some kind of mystery, and it is these chemical compounds that Fry and his team sequenced to learn more about their origin and toxicity.
Surprisingly, proteins weren't entirely new to science. In fact, many of us are painfully familiar with them.
“We analyzed the DNA sequence of the protein in loris venom and found that it was almost identical to the allergenic protein in cats,” says Fry.
“Cats excrete and coat themselves with this protein, and that's what you react to if you're allergic to them.”
Depending on where you live in the world, one in ten people will experience a runny nose, itching, or potentially life-threatening airway edema that occurs when allergenic proteins are inhaled in a cat's saliva.
These statistics are not entirely trivial, suggesting that there might be something less random about how these proteins evolved in cats and slow lorises to ward off potential threats.
“Human cat allergy is so common that it would be a wonderful coincidence if it weren't for an advanced defensive weapon like the same protein that slow lorises use,” says Fry.
“Your pet cat doesn't know about this, but he may have developed toxic defenses to keep predators as far away from him as possible.”
The discovery is rather speculative and requires further study. In any case, it is essential for mapping the immunological processes that interfere with the healing of loris bites, which could lead to better allergy treatments or even new drugs.
“Slow lorises are the only known venomous primates, and they are largely unexplored,” says Fry.
This research was published in Toxins.
Sources: Photo: Freder / E + / Getty Images
