Aortic blood flow subtraction: an alternative method for measuring total renal blood flow in conscious dogs.

TY - JOUR

T1 - Aortic blood flow subtraction: an alternative method for measuring total renal blood flow in conscious dogs.

AU - Sandgaard, N C F

AU - Andersen, J L

AU - Holstein-Rathlou, N-H

AU - Bie, P

N1 - Keywords: Angiotensin II; Animals; Antihypertensive Agents; Aorta, Abdominal; Arterial Occlusive Diseases; Benzimidazoles; Blood Flow Velocity; Blood Pressure; Carotid Arteries; Dogs; Endothelin-1; Female; Homeostasis; Regional Blood Flow; Renal Artery; Renal Circulation; Reproducibility of Results; Rheology; Subtraction Technique; Tetrazoles; Vascular Resistance; Vasoconstrictor Agents

PY - 2002

Y1 - 2002

N2 - We have measured total renal blood flow (TRBF) as the difference between signals from ultrasound flow probes implanted around the aorta above and below the renal arteries. The repeatability of the method was investigated by repeated, continuous infusions of angiotensin II and endothelin-1 seven times over 8 wk in the same dog. Angiotensin II decreased TRBF (350 +/- 16 to 299 +/- 15 ml/min), an effect completely blocked by candesartan (TRBF 377 +/- 17 ml/min). Subsequent endothelin-1 infusion reduced TRBF to 268 +/- 20 ml/min. Bilateral carotid occlusion (8 sessions in 3 dogs) increased arterial blood pressure by 49% and decreased TRBF by 12%, providing an increase in renal vascular resistance of 69%. Dynamic analysis showed autoregulation of renal blood flow in the frequency range <0.06-0.07 Hz, with a peak in the transfer function at 0.03 Hz. It is concluded that continuous measurement of TRBF by aortic blood flow subtraction is a practical and reliable method that allows direct comparison of excretory function and renal blood flow from two kidneys. The method also allows direct comparison between TRBF and flow in the caudal aorta.

AB - We have measured total renal blood flow (TRBF) as the difference between signals from ultrasound flow probes implanted around the aorta above and below the renal arteries. The repeatability of the method was investigated by repeated, continuous infusions of angiotensin II and endothelin-1 seven times over 8 wk in the same dog. Angiotensin II decreased TRBF (350 +/- 16 to 299 +/- 15 ml/min), an effect completely blocked by candesartan (TRBF 377 +/- 17 ml/min). Subsequent endothelin-1 infusion reduced TRBF to 268 +/- 20 ml/min. Bilateral carotid occlusion (8 sessions in 3 dogs) increased arterial blood pressure by 49% and decreased TRBF by 12%, providing an increase in renal vascular resistance of 69%. Dynamic analysis showed autoregulation of renal blood flow in the frequency range <0.06-0.07 Hz, with a peak in the transfer function at 0.03 Hz. It is concluded that continuous measurement of TRBF by aortic blood flow subtraction is a practical and reliable method that allows direct comparison of excretory function and renal blood flow from two kidneys. The method also allows direct comparison between TRBF and flow in the caudal aorta.

U2 - 10.1152/ajpregu.00494.2001

DO - 10.1152/ajpregu.00494.2001

M3 - Journal article

C2 - 11959697

SN - 0363-6119

VL - 282

SP - R1528-35

JO - American Journal of Physiology - Regulatory Integrative and Comparative Physiology

JF - American Journal of Physiology - Regulatory Integrative and Comparative Physiology

IS - 5

ER -