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.

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 g I/kg), CI-AKI + TMP (iohexol2.5 g I/kg + 80 mg/kg TMP), and CI-AKI + saline. The IVIM images were acquired longitudinally at baseline and 1, 24, 48, and 72 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-1α (HIF-1α) 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 h (p < 0.05). In the CI-AKI + 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 h and 72 h. In particular, these values returned to baseline levels by 72 h. No improvement was observed in the CI-AKI + saline group. ADC, D, D *, and f values negatively correlated with renal injury score (all p < 0.001, r = -0.845 to 0.913) and HIF-1α expression (all p < 0.001, r = -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.