Effects of Norepinephrine on Renal Cortical and Medullary Blood Flow in Atherosclerotic Rabbits

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