Role of Neurotensin in Radiation-Induced Hypothermia in Rats

摘要

The role of neurotensin in radiation induced hypothermia was examined.Intracerebroventricular (ICV) administration of neurotensin produced dose-dependent hypothermia. Histamine appears to mediate neurotensin-induced hypothermia because the mast cell stabilizer disodium cromoglycate and antihistamines blocked the hypothermic effects of neurotensin. An ICV pretreatment with neurotensin antibody attenuated neurotensin-induced hypothermia, but did not attenuate radiation-induced hypothermia, suggesting that radiation-induced hypothermia was not mediated by neurotensin. Exposure to ionizing radiation causes changes in core body temperature. This effect depends partly upon the species of animal, with hyperthermia occurring cats, rabbits, and humans, and a biphasic response (i.e., a fall in temperature followed by a rise) in monkeys. In rats, the direction of the temperature change is dose dependent with hyperthermia occurring when radiation doses are less than 15 Gy and hypothermia occurring when doses are greater than 20 Gy.