Previous studies have determined mice having high levels of the hormone live 30 percent longer than normal mice and are more resistant to cellular changes associated with aging, researchers said.

Klotho, discovered by Japanese scientists in 1997, is found in the membranes of certain cells, as well as in blood and cerebrospinal fluid.

Professor Carmela Abraham and colleagues at Boston University School of Medicine said they initially thought enzymes were responsible for the release of Klotho from cell membranes. They said they were surprised when their study determined insulin, a hormone usually associated with diabetes, significantly increases levels of Klotho.

Abraham is now studying ways to increase levels of Klotho to those found in young individuals -- a process that might lead to new research designed to regulate the aging process.

"In other words, compounds that would increase Klotho could become the next 'fountain of youth'," said Abraham.

The study appears in the Proceedings of the National Academy of Sciences.