Comparison of invasive dynamic blood pressure between superior mesenteric artery and common carotid artery in rats

BACKGROUND: The purpose of this study was to identify the consistency of invasive dynamic blood pressure(BP) monitoring between the superior mesenteric artery(SMA) and the common carotid artery(CCA).METHODS: Eight male Sprague-Dawley rats were cannulated in SMA and CCA simultaneously for BP monitoring, respectively.The abdominal aorta was prepared for the induction of BP change through clamping/de-clamping by a microvascular clip.The dynamic BP monitoring was performed by a polygraph system.Systolic blood pressure(SBP), diastolic blood pressure(DBP), and mean arterial pressure(MAP) values would be recorded during different time periods: the baseline(T1), the increasing period after clamping(T2), the platform period during clamping(T3), the decreasing period after de-clamping(T4), and the final platform period(T5).Three trials were performed on each rat with 15-minute intervals between consecutive monitoring.RESULTS: Systolic BP showed no significant differences between SMA and CCA.However, significant difference was found in diastolic blood pressure except at T5(P=0.534).Mean arterial pressure of two arteries were significantly different only at T1(P=0.015).The strength of association was significantly high between BP measurements through SMA and CCA(P<0.001).The BlandAltman analyses showed that mean bias of MAP changed no more than 5 mmHg and standard deviation less than 8 mmHg during T2 and T4, respectively.CONCLUSION: The study indicates SMA might be an alternative site for invasive BP monitoring during abdominal aorta occlusion and release, especially in cerebrovascular-related research.