Altered body temperature of rabbits after central injection of beta-endorphin and other peptides.

After injection of 5 micrograms into a lateral cerebral ventricle, 6 of 12 peptides induced mean changes of 0.3 degree C or more in rectal temperature of rabbits. When beta-endorphin was studied further with 1.25-5 micrograms in 10, 23 and 30 degrees C environments, it induced dose-related hypothermia in the cold, hyperthermia in the heat and progressively smaller increases in body temperature with increasing doses at 23 degrees C.