Effect of dehydration on the increase of arterial pressure and renal electrolyte excretion produced by central cholinergic stimulation in rats

ABSTRACT

Natriuresis, kaliuresis, diuresis, arterial pressure and heart rate were studied in rats following dehydration and cholinergic stimulation of the medial septal area (MSA). The increase in renal NA+ and K+ excretion produced by the injection of carbachol (2nmol) into the MSA in normal hydrated rats was abolished in 48-h water-deprived rats. Urinary volume was also reduced. Cholinergic stimulation of the MSA produced a smaller mincrease in arterial pressure in 48-h-deprived rats compared to normal hydrated animals. No change was observed in heart rate. These reults show that hydration state is essential for the central cholinergic control of electrolyte excretion and increase in arterial pressure