超声造影增强显像对自发性糖尿病大鼠肾血流灌注的实验研究

摘要

目的 探讨自发性糖尿病大鼠(Goto-Kakizaki rats,GK)肾皮质血流灌注特点及变化规律，为临床糖尿病肾损害的肾血流灌注研究提供实验依据。方法 雄性GK大鼠4、12、20周龄各10只，周龄与之匹配的雄性Wistar大鼠30只作为对照组。股静脉插管，快速注射超声造影剂SonoVue，剂量为0.028ml/100 g体质量，实时观察肾皮质显影，存储注射造影剂后0～5 min的动态图像，采用时间-强度曲线(time intensity curve,TIC)分析肾皮质的灌注特点。结果 ①各组实验大鼠肾在注射造影剂后快速增强，肾动脉-皮质-锥体-肾静脉依次显影;②各组实验大鼠肾皮质灌注TIC曲线形态为单峰式，上升支陡峭，下降支较平坦。各周龄GK大鼠肾皮质灌注的TIC曲线整体形态较同周龄Wistar大鼠宽大，随着GK大鼠周龄的增加更加明显;③与Wistar大鼠比较，各组GK大鼠TIC曲线达峰时间延长(P＜0.01)，峰值半降时间增大(P＜0.01)。12、20周龄组曲线上升支斜率减小（P＜0.05～P＜0.01），下降支斜率减小(P＜0.01)，曲线下面积增大(P＜0.05)。结论实时超声造影增强显像可以有效地观察GK大鼠肾皮质血流灌注特点及变化规律，GK大鼠早期即存在肾皮质微循环的灌注异常。%Objective To explore dynamic changes of renal cortex blood perfusion in Goto-Kakizaki rats(GK rats) by contrast-enhanced ultrasonography.The clues for early diagnosis and intervention of diabetic renal impairment may be obtained from the study.Methods Male GK rats were taken as experimental groups,and Wistar male rats were used as controls.Contrast-enhanced agent SonoVue was administered via the femoral vein cannulation in a bolus fashion.Image changes of renal cortex were observed in real time, and dynamic image changes within 0 - 5 minute after injection were observed and stored.The renal cortex blood perfusion changes were analyzed using the time-intensity curve (TIC).Results (1) The kidney was quickly enhanced after the injection of contrast agent.The renal artery, cortex, renal vein were displayed in sequence.(2)The shape of renal perfusion TIC in all the objects was a single peak,steep ascending, flat descending curve.The overall shape of TIC in GK rats was wider than controls and they were wider and wider with age increasing of the GK rats.(3) Compare to controls,the time to peak (TTP)and the half time of peak descending (HDT) in GK rats was longer (P ＜0.01), the slope rates of the ascending curve (S1) and the slope rates of the descending curve (S2) decreased and the area under the curve increased in 12-week-old and 20-week-old GK rats (P ＜ 0.05 or P ＜ 0.01).Conclusions The abnormal blood perfusion of renal cortex microcirculation was present in the early stage of diabetic in GK rats.Real-time contrast-enhanced ultrasonography and TIC could display this change effectively.