Microinjection of neurotensin into the CNS induces hyperdipsia in the rat.

Neurotensin (NT) is a neuropeptide and putative neurotransmitter that has been shown to exert a variety of effects on digestive and ingestive processes. In order to address the possibility that NT might play a role in the regulation of water intake as well, the peptide was infused into the lateral cerebral ventricle, amygdala, ventral tegmental area, lateral hypothalamus, and preoptic area of the anterior hypothalamus of rats deprived of water for 16 hours. Neurotensin produced a significant and dose-dependent increase in water intake when injected into the ventricular system but had no effect when it was applied to the other brain sites. It was concluded that this peptide may play a physiological role in the control of water ingestion and that central sites of action remain to be determined.