Effect of Afferent Renal Nerve Stimulation on Blood Pressure, Heart Rate and Noradrenergic Activity in Conscious Rats

The effects of electrical stimulation of afferent renal nerves on arterial pressure, heart rate, and alpha-methyltyrosine-induced disappearance of norepinephrine in the hypothalamus, contralateral kidney, intestine, and skeletal muscle were studied in conscious rats. There was a significant increase in arterial pressure in response to afferent renal nerve stimulation. There was no significant change in the turnover of norepinephrine in the hypothalamus. However, there was a significant increase in the turnover of norepinephrine in the skeletal muscle, a tendency toward an increase in the intestine, and no change in the contralateral kidney. These results indicate that activation of afferent renal nerve fibers does not change noradrenergic activity in the hypothalamus yet produces a differential sympathetic outflow. Secondly, the increased turnover of norepinephrine in skeletal muscle may be contributing to the increase in arterial pressure.