Experimental Studies on the Nervous Control of the Renal Circulation

Abstract

An increase in renal blood flow accompanied by the pressor response was often seen upon stimulation in the lateral column and lateral border of the anterior column of the upper dorsal segments. Renal vascular resistance in this response was usually little or only slightly increased. This change might occur due in part to an increase in cardiac output. Stimulation of the lateral column, lateral border of the anterior column and surface of the transitional zone between the anterior and posterior column from [dorsal] D5 to D12 segments resulted in an increase in blood pressure and a decrease in renal blood flow. The latter was attributed to renal vasoconstriction. Upon stimulation in the spinal cord from D13 to [lumbar] L3 segments, there usually occurred little change in both blood pressure and renal blood flow, but in some cases a decrease only in renal blood flow was observed. The existence of nerves affecting mainly the renal blood vessels was suggested. Upon stimulation in the posterior column from D1 to L3 segments, no changes were usually observed in blood pressure and renal blood flow. In case of the complete transection of the spinal cord, the results of stimulation of the spinal cord from D5 to L segments were almost similar to those without transection, although the changes in both blood pressure and renal blood flow were usually decreased. In addition, biphasic and triphasic responses observed in the latter experiment were never seen in the former.