Bear Bones and Hormones a Key to Reversing Osteoporosis?

Newswise — Michigan Technological University researcher Seth Donahue has synthesized a hormone that may be giving bears immunity from osteoporosis.

Bears typically emerge from hibernation with bones as strong as two-by-fours; in humans, such behavior would turn our bones to the relative equivalent of peppermint sticks. Why bears are able to dodge the osteoporosis bullet despite snoozing away so many months of the year has been a puzzle. Now, Donahue, an associate professor of biomedical engineering, may have solved the mystery.

In people and bears, staying active promotes strong bones. So does parathyroid hormone, but when people are sedentary, parathyroid hormone production doesn't increase. In hibernating bears, it does.

"We can't say for sure at this point that parathyroid hormone is what protects bear bones from osteoporosis during hibernation, but the results are very provocative at this point," said Donahue.

He has identified the bear gene responsible for making parathyroid hormone and has synthesized the hormone in the lab. "Our next step is to sprinkle it on bone cells and see if we get activity related to bone formation," he said.

The work holds promise for developing a new drug to reverse osteoporosis, prompting the university to enter into an agreement with Apjohn Group LLC. The Kalamazoo, Mich.-based business development advisory firm specializes in commercializing life sciences technology.

Donahue's work was first published online on April 18, 2006, in the Journal of Experimental Biology. An abstract is available at http://jeb.biologists.org/cgi/content/abstract/209/9/1630