Quinine-induced hypothermia in cold-exposed rats

Quinine HCl in doses from 10–50 mg/kg lowered the body temperatures of nonfebrile rats in the cold, primarily by suppressing shivering. However, if given an opportunity to turn on a heat lamp the rats worked much more than normal after a quinine injection and were thereby able to counteract the hypothermia to some extent. The effect of quinine is interpreted as an action on effector mechanisms rather than as an alteration of the thermal setpoint.