Low body temperature governs the decline of circulating lymphocytes during hibernation through XXXX .

@entity1 @entity2332 @entity2905 @entity329 @entity35 @entity5596 @entity855 @entity5595
Hibernation is an energy-conserving behavior consisting of periods of inhibited metabolism ('torpor') with lowered body temperature. Torpor bouts are interspersed by arousal periods, in which metabolism increases and body temperature returns to euthermia. In deep torpor, the body temperature typically decreases to 2-10   C, and major physiological and immunological changes occur. One of these alterations constitutes an almost complete depletion of circulating lymphocytes that is reversed rapidly upon arousal. Here we show that torpor induces the storage of lymphocytes in secondary lymphoid organs in response to a temperature-dependent drop in plasma levels of @entity5595 ( @entity5596 ). Regulation of lymphocyte numbers was mediated through the type 1 @entity5596 receptor ( @entity5596 (1)), because administration of a specific antagonist (W146) during torpor (in a @entity329 at    8   C) precluded restoration of lymphocyte numbers upon subsequent arousal. Furthermore, @entity5596 release from erythrocytes via @entity855 -binding cassette (ABC)-transporters was significantly inhibited at low body temperature (4   C) but was restored upon rewarming. Reversible @entity2905 also was observed during daily torpor (in a Djungarian hamster at    25   C), during forced @entity2332 in anesthetized (summer-active) hamsters (at    9   C), and in a nonhibernator ( @entity35 at    19   C). Our results demonstrate that @entity2905 during hibernation in small mammals is driven by body temperature, via altered plasma @entity5596 levels. @entity5596 is recognized as an important bioactive lipid involved in regulating several other physiological processes as well and may be an important factor regulating additional physiological processes in hibernation as well as in mediating the effects of therapeutic @entity2332 in @entity1 .
