LLUAHSC SCOPE Summer 2001

Loma Linda University researcher is featured on ‘National Geographic Explorer'

[SCOPE, Summer 2001]

Hayes
William K. Hayes, PhD, professor of natural sciences, Graduate School, "milks" a rattlesnake for venom in his laboratory in Mortensen Hall.

A Loma Linda professor in the Graduate School's department of natural sciences was featured in a segment of "United Snakes of America," a "National Geographic Explorer" program which aired on CNBC January 27 at 5:00 and 8:00 p.m.

William K. Hayes, PhD, professor of natural sciences, has been studying the venom expenditure of snakes and their strike behavior since 1988.

Recently, a film crew from "National Geographic Explorer" was on campus to interview Dr. Hayes about his extensive research on snakebites.

"Using a state-of-the-art immunological technique, enzyme-linked immunosorbent assay (ELISA), my studies were the first to provide a number of fascinating insights on venom use related to the predatory behavior of venomous snakes," Dr. Hayes explains.

According to his research, rattlesnakes meter more venom into larger prey than smaller prey, apparently through deliberate, intrinsic control of venom delivery. Rattlesnakes also attempt to inject more venom into birds and lizards than into smaller animals such as mice.

Rattlesnakes are almost 90 percent effective in delivering their venom when biting a mouse, while the remaining 10 percent is spilled harmlessly on the skin.

"Wheras large snakes inject more venom than smaller snakes, as might be expected," continues Dr. Hayes, "hungry snakes inexplicably release less venom than well-fed snakes."

"We've also studied several nonvenomous snakes that produce a secretion from the Duvernoy's gland that is toxic enough to put children into the hospital," Dr. Hayes adds.

More recently, Dr. Hayes and his colleagues have begun to study defensive strikes, which are particularly important for human beings to understand.

"We've learned that the duration of fang contact during defensive bites--typically 0.07 seconds--is much briefer than that of predatory bites, which are typically 0.15 seconds," Dr. Hayes advises. "The brevity of these strikes, although probably adaptive to minimize the risk of retaliatory injury from a predator or antagonist, may limit the quantity of venom that can flow into the victim."

More exciting for Dr. Hayes and his team is the possibility that certain articles of clothing, such as blue jeans, may further interrupt venom delivery.

"Obviously, millions of Americans would be interested to learn if jeans significantly reduce the severity of envenomation--a hypothesis we are currently exploring," Dr. Hayes concludes.

[SCOPE, Summer 2001]