POLAR BEARS -A Unique Physiology

Polar Bears feed for only about four months out of the year and fast for the other eight. Today, we’ll find out why scientists are taking a closer look at the mechanics of polar bear hibernation. I’m Jim Metzner and this is the Pulse of the Planet, presented by The American Museum of Natural History.

We’re listening to the sounds of polar bears. Dr. Malcolm Ramsay is a professor of Biology at the University of Saskatchewan in Canada.

“There are two major aspects of their physiology that allows them to have such a funny feeding regimen. One is that they can pack on vast amounts of fat very, very quickly. They’re using that body fat to supply the energy that keeps them going for the rest of the year. The other thing is they don’t lose body protein when they*re fasting. Proteins are constantly being broken down every day as part of the wear and tear of the body. And normally we would eliminate these breakdown products from our body in the urine and we*d eat more protein to replace them. What the Polar bears are doing when they’re fasting is recycling those waste products. Rather than eliminating them from the body, they rebuild them back into protein again. Even after a six or eight month fast, there’s very little loss in body protein. And that*s really quite remarkable.”

Studying Polar Bear hibernation could lead to some breakthroughs in medical science.

“Our working hypothesis is that the Polar bears, when they*re fasting and recycling proteins, they’re using the same biochemical pathways that would exist in any other mammal, including humans, but perhaps augmenting them in very special ways. And, if that hypothesis proves to be true, then it is within the realm of possibility that we could use pharmaceutical means to induce the same processes in humans. For example, if we could induce the same recycling of proteins in the bodies of these people with damaged kidneys, then it would greatly reduce the need for having to use an artificial kidney, and therefore it should improve dramatically the quality of their life.”

Additional funding for Pulse of the Panet comes from the National Science Foundation.

POLAR BEARS -A Unique Physiology

How can Polar bears fast for eight months? The answer may provide clues to new treatments for some human diseases.
Air Date:12/14/1998
Scientist:
Transcript:

Polar Bears feed for only about four months out of the year and fast for the other eight. Today, we'll find out why scientists are taking a closer look at the mechanics of polar bear hibernation. I'm Jim Metzner and this is the Pulse of the Planet, presented by The American Museum of Natural History.

We're listening to the sounds of polar bears. Dr. Malcolm Ramsay is a professor of Biology at the University of Saskatchewan in Canada.

"There are two major aspects of their physiology that allows them to have such a funny feeding regimen. One is that they can pack on vast amounts of fat very, very quickly. They're using that body fat to supply the energy that keeps them going for the rest of the year. The other thing is they don't lose body protein when they*re fasting. Proteins are constantly being broken down every day as part of the wear and tear of the body. And normally we would eliminate these breakdown products from our body in the urine and we*d eat more protein to replace them. What the Polar bears are doing when they're fasting is recycling those waste products. Rather than eliminating them from the body, they rebuild them back into protein again. Even after a six or eight month fast, there's very little loss in body protein. And that*s really quite remarkable."

Studying Polar Bear hibernation could lead to some breakthroughs in medical science.

"Our working hypothesis is that the Polar bears, when they*re fasting and recycling proteins, they're using the same biochemical pathways that would exist in any other mammal, including humans, but perhaps augmenting them in very special ways. And, if that hypothesis proves to be true, then it is within the realm of possibility that we could use pharmaceutical means to induce the same processes in humans. For example, if we could induce the same recycling of proteins in the bodies of these people with damaged kidneys, then it would greatly reduce the need for having to use an artificial kidney, and therefore it should improve dramatically the quality of their life."

Additional funding for Pulse of the Panet comes from the National Science Foundation.