Experimental Biology 2011 - Hibernation and Fasting

Here are highlights of my favorite abstracts covering the topics of hibernation and fasting that were presented at the Experimental Biology meeting last week:

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-Drs. Allyson Hindle and Sandra Martin from the University of Colorado Denver in Aurora, CO presented "Muscle regeneration occurs in late hibernation despite continued loss of body mass." They showed evidence that the muscle volume of hibernating 13-lined ground squirrels (Ictidomys tridecemlineatus) declined from the onset of hibernation (October) through early February. This was expected since the animals were fasting and not active during that time. What was interesting, however, was that muscle volume actually began to increase significantly during the remaining months of hibernation even though the animals continued to lose total body mass. Image Source: University of Texas, El Paso.

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-Researchers investigating elephant seals have discovered that antioxidant levels are increased with prolonged fasting offering protection from tissue damage caused by oxidative stress and inflammation. This is remarkable since fasting in terrestrial mammals typically leads to increased expression of pro-oxidative stress markers and inflammation. (Jose Vazquez-Medina, and Drs. Tania Zenteno-Savin, Henry Forman, Daniel Crocker , Rudy Ortiz; "The antioxidant system of the elephant seal during their natural prolonged fast") Image Source: Robert Siegel, Stanford University.

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I really found this article interesting. Knowing that animals gain muscle mass while they hibernate is fascinating and Iâd like to know more about how that happens. Iâm not sure itâs a good thing they are losing body mass though because isnât it healthier to have more body mass then muscle mass? If fasting increases the antioxidant levels in the body how come itâs not healthy to fast for weight loss and is that why you have to fast for a prolonged period of time before a blood test? If you could please get back to me Iâd appreciate it.

Hey Dr. Dolittle,
I think that your post really came to my attention since Iâm not familiar with animal hibernation or fasting. It was really interesting to read! Animals amaze me how they can actually go that long with no food or exorcise. What makes the ground squirrels muscle volume increase while it is sleeping? I was wondering since the elephant seals reason has to do with antioxidants.

to Halie J: The whole point of these presentations is that certain animals can do things that ARE unhealthy when we humans do them. Now we need to ask WHY ground squirrels can gain muscle mass while still and immobile, because we can't. And why elephant seals increase antioxidants during fasting, because we don't. We're humans and we neither hibernate nor seasonally fast.