Experimental study on the prevention of iodinated contrast-induced kidney injury in rats by tetramethylpyrazine and the detection of their renal function by intravoxel incoherent motion.

Abstract

PURPOSE: Experimental study on tetramethylpyrazine (TMP) for preventing contrast-induced renal injury in rats using magnetic resonance intravoxel incoherent motion (IVIM) to assess renal water diffusion properties and perfusion. METHODS: Eighty-four Sprague-Dawley(SD) male rats were divided into four groups: control (saline), CI-AKI (iohexol 2.5&#xa0;g I/kg), CI-AKI&#x2009;+&#x2009;TMP (iohexol2.5&#xa0;g I/kg&#x2009;+&#x2009;80&#xa0;mg/kg TMP), and CI-AKI&#x2009;+&#x2009;saline. The IVIM images were acquired longitudinally at baseline and 1, 24, 48, and 72&#xa0;h after the administration of the drugs to evaluate the apparent diffusion coefficient (ADC), pure diffusion coefficient (D), perfusion-related value (D*), and perfusion fraction (f) values. Serum creatinine (SCR), histology, and hypoxia-inducible factor-1&#x3b1; (HIF-1&#x3b1;) immunoexpression were determined. RESULTS: In the control group, there were no significant changes in ADC, D, D*, and f values of renal cortex (CO), outer medulla (OM), and inner medulla (IM) at all time points. In the CI-AKI group, ADC, D, D*, and f values of renal CO, OM, and IM reached the lowest level at 48&#xa0;h (p&#x2009;<&#x2009;0.05). In the CI-AKI&#x2009;+&#x2009;TMP group, the ADC, D, D*, and f values of renal CO, OM, and IM were significantly higher than those of the CI-AKI group at 48&#xa0;h and 72&#xa0;h. In particular, these values returned to baseline levels by 72&#xa0;h. No improvement was observed in the CI-AKI&#x2009;+&#x2009;saline group. ADC, D, D *, and f values negatively correlated with renal injury score (all p&#x2009;<&#x2009;0.001, r&#x2009;=&#x2009;-0.845 to 0.913) and HIF-1&#x3b1; expression (all p&#x2009;<&#x2009;0.001, r&#x2009;=&#x2009;-0.846 to 0.920). CONCLUSION: TMP prevents early contrast-induced renal injury and allows noninvasive detection of renal water diffusion properties and perfusion function by IVIM.