Application of ultrasound microbubble contrast to evaluate the effect of sitaxentan on renal microvascular perfusion in beagles undergoing cardiopulmonary bypass.

Abstract

We aimed to evaluate the effect of sitaxentan on renal microvascular perfusion via application of ultrasound microbubble contrast. Male beagles were randomly divided into: Sham, cardiopulmonary bypass (CPB) and sitaxentan-infused (Sit) groups (n = 6). The ascending slope rate (ASR), area under the curve (AUC), derived peak intensity, and time to peak (TTP) were obtained via ultrasound microbubble contrast before CPB (T1), after 1 h CPB (T2), at end of CPB (T3), and 2 h after CPB (T4). Compared with the Sham group, the CPB group had lower ASR of the renal cortex and medulla at T2-4, higher AUC and TTP at T3-4, and lower derived peak intensity at T4. The ASR at T2-4 in the Sit group was lower, TTP was higher at T2-4, and AUC was higher at T3-4 (P < 0.05). Compared with the CPB group, the Sit group had higher ASR of the renal cortex and medulla at T3-4 and AUC and TTP at T3-4 (P < 0.05). Compared with that at T1, the ASR of the renal cortex and medulla at T2-4 in the CPB group was lower, and AUC and TTP were higher at T3-4. The ASR of the renal cortex and medulla at T2-4 in the Sit group was lower, TTP was higher at T2-4, and AUC was higher at T4 (P < 0.05). Ultrasound microbubble contrast could be effectively used to evaluate renal microvascular perfusion peri-CPB in beagles, which was prone to decrease and could be improved via pretreatment with sitaxentan.