Natures wonders: Hibernating bears (Introduction)

by David Turell @, Tuesday, July 05, 2016, 15:15 (2814 days ago) @ David Turell

The hibernation process is not explained but fascinating:-http://www.nytimes.com/2016/07/05/science/learning-from-healthy-bears-you-mean-we-should-hibernate.html?nl=todaysheadlines&emc=edit_th_20160705-"Gain a few hundred pounds and lie around in bed for months, and you are likely to develop a host of ailments, from diabetes and heart failure to muscle loss, osteoporosis and bedsores.-"Unless, that is, you happen to be a bear.-***-"Confirming work by other researchers, Dr. Godsk Jorgensen and his colleagues found that bears' heart rate slowed sharply during hibernation, from about 75 beats a minute to as few as 10, with pauses that sometimes lasted 19 seconds or more.-“'I once had a patient with a pause of 13 seconds,” Dr. Godsk Jorgensen said. “When you have that, you go around and you faint and hit your head.”-***-"The researchers also identified clusters of blood cells on the bear's ultrasound, called “smoke,” that are seen in humans who have severe heart failure or atrial fibrillation, a condition that raises the risk of blood clots and stroke.-***-"Hibernating bears, grown fat from summer feasting, do not eat, drink, urinate or defecate while they are hibernating. But they lose no muscle mass from inactivity. Platelets in the bears' blood become less sticky, acting as a natural blood thinner, the researchers found, perhaps to counteract blood clots that could form during long periods of immobility. The bears' metabolism drops to 25 percent of its normal state and their kidneys stop functioning, yet they do not have kidney failure.-***-"Obese bears are healthier; in fact, they are more reproductively fit,” said Heiko T. Jansen, a professor at the College of Veterinary Medicine at Washington State University who presented at the meetings. “They have all the advantages, which is so counterintuitive to human biology.”-"In research financed in part by the pharmaceutical company Amgen, Dr. Jansen and his colleagues found that bears' handling of insulin appears to vary with the seasons, with resistance increasing during hibernation and sensitivity increasing in summer.-"Fat cells of hibernating bears treated with a blood serum from “summer” bears become more insulin sensitive, the researchers found.-Comment: Darwin would say this developed bit by bit. I don't see how, because it seems like life in very slow motion, fatal for us. Fat bears are fit, humans are not. Saltation again.


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