SAN FRANCISCO, CA.--Geriatric rats instinctively ward off sickness by huddling in hot spots, and ongoing studies of their behavior may suggest drug-free strategies to help older people fight infections, University of Delaware researchers reported today at the Experimental Biology '98 meeting.
"Most older rats, like many older people, either don't get fevers or get low fevers when they have an infection," explains Evelyn Satinoff, chairperson of UD's Department of Psychology and one of the nation's leading researchers in thermoregulation. "While an extremely high fever may be life-threatening, especially for very young children, moderate fever is widely believed to be an essential tool in the immune system's arsenal. In most cases, fever helps the body combat dangerous pathogens."
Compared to young rats, older rats housed at room temperature typically get much lower fevers, but new UD data shows "they can get a fever when they're allowed to select the temperature of their environment," reports Maria Florez-Duquet, a post-doctoral neuroscientist at UD who authored the Experimental Biology paper, along with Research Associate Elizabeth D. Peloso and Satinoff.
If the UD research pans out, Satinoff says, it may ultimately help doctors more easily fight infections among older patients. Although Satinoff emphasizes that the UD work is still preliminary, helping to combat infections "might be as simple as placing an older patient in a very warm room to induce fever," she says.
Laboratory rats reach the end of their lives around 30 months of age, Florez-Duquet notes. By 24 to 26 months of age, older rats in Satinoff's experiments demonstrate a strong preference for heated areas. "If you're a lab rat with an infection," she says, "selecting a warm environment clearly is a smart thing to do."
To learn more about the drive to survive in older rats, the UD research team
initially injected lipopolysaccharide (LPS), a fever-induct
Contact: Ginger Pinholster
University of Delaware