Internephron coupling by conducted vasomotor responses in normotensive and spontaneously hypertensive rats.

TY - JOUR

T1 - Internephron coupling by conducted vasomotor responses in normotensive and spontaneously hypertensive rats.

AU - Wagner, A J

AU - Holstein-Rathlou, N H

AU - Marsh, D J

N1 - Keywords: Animals; Arterioles; Blood Pressure; Body Weight; Hypertension; Male; Models, Biological; Nephrons; Potassium Chloride; Rats; Rats, Inbred SHR; Rats, Sprague-Dawley; Reference Values; Signal Transduction; Software; Vasoconstriction; Vasomotor System; Videotape Recording

PY - 1997

Y1 - 1997

N2 - We compared conducted vasomotor responses in juxtamedullary microcirculation in normotensive Sprague-Dawley (SD) and spontaneously hypertensive rats (SHR). The goals of the study were as follows: 1) decide whether internephron coupling is facilitated by conducted vasomotor responses; 2) determine whether the magnitude of induced vasoconstriction decreases with increasing distance from the stimulation site; and 3) determine whether the response is stronger in SHR than in SD rats. Microapplication of KCl to the distal afferent arteriole caused local vasoconstriction that was rapidly conducted (speed > 3.0 mm/s) into the cortical radial artery and neighboring afferent arterioles in SD and SHR. The strength of the response was significantly greater (approximately 40%, P < 0.025) in SHR than SD, and the magnitude decreased monotonically with increasing distance from the stimulation site in both strains. Mechanical length constants were similar in SD and SHR (approximately 325 microm), indicating that the signal responsible for the effect decays at the same rate in both strains. We conclude that internephron coupling strength is significantly greater in SHR and that internephron coupling is due to vascular events conducted along the preglomerular vasculature.

AB - We compared conducted vasomotor responses in juxtamedullary microcirculation in normotensive Sprague-Dawley (SD) and spontaneously hypertensive rats (SHR). The goals of the study were as follows: 1) decide whether internephron coupling is facilitated by conducted vasomotor responses; 2) determine whether the magnitude of induced vasoconstriction decreases with increasing distance from the stimulation site; and 3) determine whether the response is stronger in SHR than in SD rats. Microapplication of KCl to the distal afferent arteriole caused local vasoconstriction that was rapidly conducted (speed > 3.0 mm/s) into the cortical radial artery and neighboring afferent arterioles in SD and SHR. The strength of the response was significantly greater (approximately 40%, P < 0.025) in SHR than SD, and the magnitude decreased monotonically with increasing distance from the stimulation site in both strains. Mechanical length constants were similar in SD and SHR (approximately 325 microm), indicating that the signal responsible for the effect decays at the same rate in both strains. We conclude that internephron coupling strength is significantly greater in SHR and that internephron coupling is due to vascular events conducted along the preglomerular vasculature.

M3 - Journal article

C2 - 9087681

SN - 0002-9513

VL - 272

SP - F372-9

JO - American Journal of Physiology

JF - American Journal of Physiology

IS - 3 Pt 2

ER -