Menthol and nicotine oppositely modulate body temperature in the rat

Menthol is a prominent additive in many tobacco products. To investigate possible interactions with nicotine, (−)-menthol (200 or 400 mg/kg) and (−)-nicotine (0.5 mg/kg) were injected subcutaneously in rats, and body temperature, which is modulated by brain nicotinic acetylcholine receptors, was measured. Nicotine caused robust (− 1.6 °C) hypothermia, the magnitude and time course of which was not altered by menthol pretreatment. Menthol alone produced mild (0.4–0.8 °C) hyperthermia, which was not secondary to locomotor activation. Nicotine and menthol influence body temperature independently and oppositely; menthol does not appear to influence the function of the central nicotinic receptors that control body temperature.