Thermal responses of hamsters to endotoxin

Abstract

1. 1.|These experiments were undertaken to determine whether small hibernators develop fever when challenged with endotoxin. 2. 2.| S. enteritidis endotoxin (LPS), in doses smaller than 10 μg kg −1 had no demonstrable thermal effects in euthermic hamsters; in doses larger than 10 μg kg −1, it caused a fall of body temperature ( T co. The duration of this fall appeared to be dose dependent. A torpor-like state was produced by 30 μg kg −1 or more of LPS. 3. 3.|When given a choice of ambient temperatures ( T a, hamsters treated with pyrogen-free saline (PFS) selected a T a of ca. 30°C; their T co stabilized around 37°C. When treated with 20 μg kg −1 of LPS, they did not develop either hypothermia or fever; they selected a T a similar to that when they were treated with PFS. 4. 4.|These results suggest that the thermal responses of hamsters to LPS vary with the T a and may depend on whether the animals can utilize behavioural thermoregulation.