Effect of intracerebroventricular injection of pentagastrin on rat drinking behavior.

Intracerebroventricular (icv) injection of pentagastrin showed a powerful, dose dependent antidipsogenic effect in the rat. Drinking behavior stimulated by 48 h water deprivation was inhibited by 2000 ng of pentagastrin which also blocked, at lower doses, water intake induced by icv injection of angiotensin II (100 ng) and carbachol (150 ng). Pentagastrin was less effective on food intake stimulated by 24 h starvation. The antidipsogenic effect was not a consequence of behavioral alteration. It is suggested that gastrin-like peptides in the brain may play a role in the regulation drinking, acting as thirst inhibitors.