Bombesin:potent effects on thermoregulation in the rat.

Several vasoactive peptides administered intracisternally have been assessed for the effect of lowering the core temperature of rats exposed to cold. Peptides structurally related to neurotensin lower core temperature while those related to substance P do not. The tetradecapeptide bombesin, orginally isolated from the extracts of the skin of the frog Bombina bombina, is 10(4) times more potent than neurotensin in lowering core temperature, with a minimal effective dose less than or equal to 1 nanogram per 200 grams of body weight. Thus bombesin is one of the most potent peptides reported to affect the central nervous system.