[The effects of visual and auditory stimulation on arterial pressure and urinary sodium excretion in rats]

Countless sistemic alterations are broken out by stimuli originated by environmental, nutritional and hormonal conditions that are disadvantageous. In order to verify the effects of these stimuli on the arterial pressure and the urinary excretion of sodium, a group of 100 animals were submitted to illumination for 24 hours, auditive stimulation, dehydration and injection of adrenaline. The results show that constant illumination provokes and increase of arterial pressure (p less than 0.01), that is installed in the first 24 hours and its kept until the end of the experiment. The phasic auditive stimulation encourages an increase of arterial pressure (p less than 0.01) and its consistent to every stimulation. The arterial pressure amount in the introduction of prolonged auditive stimulation (p less than 0.01) but decreases in function of the time of the application of the stimulus. The application of illumination followed by injection of adrenaline, and illumination followed by dehydration not changing the response obtained us an isolated luminous stimulus. The urinary sodium excretion, was increased (p less than 0.01). Based on the results we arrived to the following conclusions: 1) The application of constant illumination and auditive stimulation provoke an increase of arterial pressure; 2) The pressuring responses to the phasic and continuous auditive stimulations are different; 3) There is an increase in the urinary sodium excretion.