Abstract：
OBJECTIVE: The aim of this study was to explore the effect of norepinephrine (NE) on renal cortical and medullary blood flow in atherosclerotic rabbits without renal artery stenosis.
METHODS: Atherosclerosis was induced in 21 New Zealand white rabbits by feeding them a cholesterol-rich diet for 16 weeks. Thirteen healthy New Zealand white rabbits were randomly selected as controls. After atherosclerosis induction, standard ultrasonography was performed to confirm that there was no plaque or accelerated flow at the origin of the renal artery. Contrast-enhanced ultrasound (CEUS) was performed at baseline and during intravenous injection of NE. The degree of contrast enhancement of renal cortex and medulla after the injection of contrast agents was quantified by calculating the enhanced intensity.
RESULTS: The serum nitric oxide (NO) level in atherosclerotic rabbits was higher than that in healthy rabbits (299.6±152 vs. 136.5±49.5, P<0.001). The infusion of NE induced a significant increase in the systolic blood pressure (112±14 mmHg vs. 84±9 mmHg, P=0.016) and a significant decrease in the enhanced intensity in renal cortex (17.78±2.07 dB vs. 21.19±2.03 dB, P<0.001) and renal medulla (14.87±1.82 dB vs. 17.14±1.89 dB, P<0.001) during CEUS. However, the enhanced intensity in the cortex and medulla of healthy rabbits after NE infusion showed no significant difference from that at baseline.
CONCLUSIONS: NE may reduce renal cortical and medullary blood flow in atherosclerotic rabbits without renal artery stenosis, partly by reducing the serum NO level.
METHODS: Atherosclerosis was induced in 21 New Zealand white rabbits by feeding them a cholesterol-rich diet for 16 weeks. Thirteen healthy New Zealand white rabbits were randomly selected as controls. After atherosclerosis induction, standard ultrasonography was performed to confirm that there was no plaque or accelerated flow at the origin of the renal artery. Contrast-enhanced ultrasound (CEUS) was performed at baseline and during intravenous injection of NE. The degree of contrast enhancement of renal cortex and medulla after the injection of contrast agents was quantified by calculating the enhanced intensity.
RESULTS: The serum nitric oxide (NO) level in atherosclerotic rabbits was higher than that in healthy rabbits (299.6±152 vs. 136.5±49.5, P<0.001). The infusion of NE induced a significant increase in the systolic blood pressure (112±14 mmHg vs. 84±9 mmHg, P=0.016) and a significant decrease in the enhanced intensity in renal cortex (17.78±2.07 dB vs. 21.19±2.03 dB, P<0.001) and renal medulla (14.87±1.82 dB vs. 17.14±1.89 dB, P<0.001) during CEUS. However, the enhanced intensity in the cortex and medulla of healthy rabbits after NE infusion showed no significant difference from that at baseline.
CONCLUSIONS: NE may reduce renal cortical and medullary blood flow in atherosclerotic rabbits without renal artery stenosis, partly by reducing the serum NO level.
摘要：
目的：本研究的目的是探讨去甲肾上腺素（NE）对无肾动脉狭窄的动脉粥样硬化兔肾皮质和髓质血流的影响。
方法：在21只新西兰大白兔中通过喂养富含胆固醇的饮食16周来诱导动脉粥样硬化。随机选择13只健康的新西兰白兔作为对照。动脉粥样硬化诱导后，进行标准超声检查以确认肾动脉起点无斑块或血流加速.在基线和静脉注射NE期间进行超声造影（CEUS）。通过计算增强强度来量化注射造影剂后肾皮质和髓质的对比增强程度。
结果：动脉粥样硬化兔的血清一氧化氮（NO）水平高于健康兔（299.6±152vs.136.5±49.5,P<0.001)。输注NE引起收缩压显着增加（112±14mmHg与84±9mmHg，P=0.016），并且肾皮质增强强度显着降低（17.78±2.07dB与21.19±2.03dB,P<0.001）和肾髓质（14.87±1.82dBvs.17.14±1.89dB,CEUS期间P<0.001)。然而,NE输注后健康兔皮质和髓质的增强强度与基线无显著差异。
结论：NE可减少无肾动脉狭窄的动脉粥样硬化兔的肾皮质和髓质血流量，部分通过降低血清NO水平。
方法：在21只新西兰大白兔中通过喂养富含胆固醇的饮食16周来诱导动脉粥样硬化。随机选择13只健康的新西兰白兔作为对照。动脉粥样硬化诱导后，进行标准超声检查以确认肾动脉起点无斑块或血流加速.在基线和静脉注射NE期间进行超声造影（CEUS）。通过计算增强强度来量化注射造影剂后肾皮质和髓质的对比增强程度。
结果：动脉粥样硬化兔的血清一氧化氮（NO）水平高于健康兔（299.6±152vs.136.5±49.5,P<0.001)。输注NE引起收缩压显着增加（112±14mmHg与84±9mmHg，P=0.016），并且肾皮质增强强度显着降低（17.78±2.07dB与21.19±2.03dB,P<0.001）和肾髓质（14.87±1.82dBvs.17.14±1.89dB,CEUS期间P<0.001)。然而,NE输注后健康兔皮质和髓质的增强强度与基线无显著差异。
结论：NE可减少无肾动脉狭窄的动脉粥样硬化兔的肾皮质和髓质血流量，部分通过降低血清NO水平。
