AJP - Regulatory, Integrative and Comparative Physiology, Vol 265, Issue 2 290-R301, Copyright © 1993 by American Physiological Society
Effects of renal receptor stimulation on neurons within the ventrolateral medulla of the cat
M. A. Vizzard, A. Standish and W. S. Ammons
Department of Physiology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
Experiments were performed to determine if activation of renal receptors by
occlusion of the renal artery, renal vein, or ureter would alter activity
of cells within the ventrolateral medulla of the cat. Extracellular unit
recordings were obtained from 195 cells located within the rostral
ventrolateral medulla of 90 alpha-chloralose-anesthetized cats. Fifty-five
of 195 cells (28.2%) tested for responses to renal receptor activation
responded to at least one of the occlusions. Occlusion of the ureter
increased the activity of 25 cells from 9.7 +/- 3.7 to 23.0 +/- 6.5
impulses/s and decreased the activity of 5 cells from 11.9 +/- 3.6 to 3.5
+/- 1.2 impulses/s. Occlusion of the renal vein increased the activity of
seven cells from 7.5 +/- 3.3 to 22.3 +/- 7.3 impulses/s and decreased the
activity of six cells from 13.8 +/- 3.8 to 4.1 +/- 2.0 impulses/s. Renal
artery occlusion elicited solely excitatory responses from 43 cells.
Thirty-one of the 43 cells increased their activity within 0-3 s of the
onset of renal artery occlusion from 4.1 +/- 0.8 to 12.6 +/- 1.2
impulses/s. Renal artery occlusion increased the activity of 10 out of 43
cells with a mean latency of 26.1 +/- 6.5 s from 8.3 +/- 2.5 to 29.6 +/-
9.3 impulses/s. Twenty-four of the 55 (43.6%) responders were responsive to
two or more forms of renal receptor activation. These results demonstrate
that activation of renal mechanoreceptors and chemoreceptors affects cells
within the ventrolateral medulla of the cat.(ABSTRACT TRUNCATED AT 250
WORDS)
