Effect of hypobaric hypoxia and almitrine on voluntary salt and water intake in carotid body denervated spontaneously hypertensive rats.

The effect of moderate hypobaric hypoxia and almitrine bismesylate (almitrine) on salt and water intake was investigated in carotid body denervated (CBD) and sham-operated (SO) spontaneously hypertensive rats (SHR). The animals were kept singly in metabolic cages and given free access to food, water and a 2.5% NaCl-solution. Oral administration of almitrine and exposure to hypobaric hypoxia for five days evoked a suppression of voluntary salt intake in SO-SHR, but not in CBD-SHR. Exposure of SO and CBD-SHR to hypobaric hypoxia resulted in a significant decrease in water intake in animals of both groups on the first day of hypoxia. Stimulation of the arterial chemoreceptors by almitrine induced no change in water intake similar to that evoked by hypobaric hypoxia. These results prove that stimulation of the arterial chemoreceptors has a direct effect on salt appetite but not on water intake in SHR.