Researchers have found that they could borrow a dose of poison by eating toxic toads, then recycling the toxins. 

    That's exactly the interesting relationship between an Asian snake and a species of toad, according to a team of researchers from Old Dominion University in Norfolk, Va. They published results of research in online issue of the journal Proceedings of the National Academy of Sciences on Tuesday.

    Herpetologists Deborah Hutchinson and her colleagues made their case by testing the Asian snake Rhabdophis tigrinus on several Japanese islands, one with a large population of the toxic toads and another with none, and compared them with snakes from the Japanese island of Honshu, where toads are few.

    In the PNAS paper, they describe dietary sequestration of toxins by the snakes. The process allows the snakes to store toxins from the toads in their neck glands. The presence of toxins in the snakes' neck glands depended upon their access to the toads.

    Snakes without the borrowed toxins were more likely to turn and flee from danger than to hold their ground and perform a toxin-releasing defensive maneuver.

    Many invertebrates sequester dietary toxins for use in defense, including milkweed insects and sea slugs. But vertebrate examples of toxin sequestration, especially from vertebrate prey, are rare. "A snake that's dependent on a diet of toads for chemical defense is highly unusual," said Hutchinson.

    Hutchinson said the research had identified six compounds in the snakes that may hold promise in medical treatments for people suffering from hypertension and related blood pressure disorders.