Myh11R247C杂合突变小鼠胸升主动脉在去甲肾上腺素诱导高血压模型中的病理生理研究

ObjevtiveTo explore the thoracic ascending aortic （TAA） pathophysiological characteristics of heterozygous mutantMyh11^R247C/+mice under the norepinephrine-induced hypertension mode.MethodsFemale heterozygous mutantMyh11^R247C/+and wild typeMyh11^+/+mice were selected as experimental group (HET group) and control group (WT group), respectively. The hypertensive model was induced by intraperitoneal injection of norepinephrine (NE), and TAA diameter and invasive blood pressure (Bp) data were collected dynamically in real time using high-frequency ultrasound imaging and invasive arterial blood pressure monitoring technique, so as to indirectly analyze TAA compliance of two groups of mice. At the same time, the incidences of hemothorax and TAA rupture were further analyzed by autopsy and histology.ResultsAfter injection of NE, heterozygous mice did not show a higher Bp increase percentage in systole or diastole comparing with wildtype mice. However, heterozygous mice exhibited 17% and 32% higher TAA diameter dilation percentage than wildtype ones in systole and diastole respectively. Two heterozygous mice had TAA dissection and rupture, and the incidence of hemothorax in heterozygous mice (3/5) was higher than that in wildtype (0/5).ConclusionIt was very likely that the altered TAA wall compliance of mutantMyh11^R247C/+mice had led to a higher TAA dilation degree than that in wildtype, and even could be the potential reason of TAA dissection and rupture.