Fever and behavioral thermoregulation in young and old rats.

摘要: At standard laboratory ambient temperatures (Ta) of 20–24°C, peripheral injections lipopolysaccharide (LPS) reliably produce fever in young rats. In contrast, old rats may show a blunted fever, no or even hypothermia after LPS. the present study we hypothesized that might use behavioral thermoregulation to help them develop fever. Young and were implanted with temperature transmitters. least 1 wk postoperatively they placed thermally graded alleyway (Ta10–40°C). On third sixth day taken out gradient, at an Ta 23°C, injected intraperitoneally LPS saline, left 23°C for 3 h. end time, all had become febrile, whereas not. When replaced thermal animals continued was similar 23°C. The chose significantly warmer positions gradient than did only then became febrile. Although there tendency prefer higher these differences not significant. However, These results suggest increased set point rats, but could febrile responses warm selected.