Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: Karen W. on 12/03/2007 03:26:18
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I know their bodies produce some kind of plug or blockage during hibernation, but how does having all that fecal matter and Urine build up in their bodies not kill them, or at least poison their system?
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From the new scientist:
During their hibernation, the bears neither defecate or urinate. This would normally mean that nitrogenous wastes during that time would cause poisoning to the urinal system. However this it does not do. The bear solves its nitrogenous waste problem by a form of recycling." The hibernating bears body diverts nitrogen from pathways that synthesise urea into pathways that generate amino acids and new proteins. And it does this by glycerol (produced when fats are metabolized) and recycled nitrogen as the building blocks
From www.bear.org
To remain in good physical condition for months without eating requires change in a bear’s body chemistry. Some of the physiological changes in healthy hibernating bears would be a real problem for people. How hibernating bears remain healthy in winter and how their physiological adaptations might be useful in human medicine are subjects of study at some of North America’s leading medical research centers. For example, bears living off their accumulated body fat have hibernating cholesterol levels more than twice summer levels and more than twice as high as the normal cholesterol levels of most humans. Yet bears exhibit no hardening of the arteries or formation of cholesterol gallstones. Medical studies reveal hibernating bears produce a bile juice, ursodeoxycholic acid that may help them avoid problems with gallstones. When this acid is given to people it dissolves gallstones and eliminates the need for surgery. Hibernating black bears also exhibit reduced kidney function. They do not urinate for months but still do not poison their bodies with waste products such as urea. Urea is somehow broken down and its nitrogen is reused to build protein. The ability to build protein while fasting allows black bears to maintain their muscle and organ tissue throughout the winter. They only use up fat. Evidence is accumulating that hormone-like substances control physiological changes in hibernating black bears. These substances also produce hibernation-like effects when injected into other species—both other hibernators and non-hibernators, suggesting potential human medical applications.
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OOOOH PAul doth they think someday that it might bring on sleep if one day they can use it for humans who perhaps have a sleep disorder?? Not That We want NEIL sleeping All winter.. LOL But perhaps at regular intervals, and me too!!!! I'll Volunteer..! Thanks so much for the information. I did not know there was a way for their body to break down the urea into nitrogens to build proteins for the winter. Did it say what the process was that broke that down?
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OOOOH PAul doth they think someday that it might bring on sleep if one day they can use it for humans who perhaps have a sleep disorder
One never knows. There is a lot of interesting information on www.bear.org
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It is a cool site paul. Its nice to see a kids section!
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interesting info Paul...
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http://en.wikipedia.org/wiki/Hydrogen_sulfide#Induced_hibernation
n 2005 it was shown that mice can be put into a state of suspended animation by applying a low dosage of hydrogen sulfide (80 ppm H2S) in the air. The breathing rate of the animals sank from 120 to 10 breaths per minute and their temperature fell from 37°C to 2°C above ambient temperature (in effect, they had become cold-blooded). The mice survived this procedure for 6 hours and afterwards showed no negative health consequences. [2]
Such a hibernation occurs naturally in many mammals and also in toads, but not in mice. (Mice can fall into a state called clinical torpor when food shortage occurs). If the H2S-induced hibernation can be made to work in humans, it could be useful in the emergency management of severely injured patients, and in the conservation of donated organs.
As mentioned above, hydrogen sulfide binds to cytochrome oxidase and thereby prevents oxygen from binding, which leads to the dramatic slowdown of metabolism. Animals and humans naturally produce some hydrogen sulfide in their body; researchers have proposed that the gas is used to regulate metabolic activity and body temperature, which would explain the above findings.[3]
In 2006 it was shown that the blood pressure of mice treated in this fashion with hydrogen sulfide did not significantly decrease.
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interesting info Paul...
it is, i like bears.