Characterization of circulatory disorders in -thalassemic mice by

-Thalassemia is an inherited hematological disease caused by a decrease or absence of production of -globin that requires chronic therapeutic interventions. This condition leads to important arterial and venous thromboembolic events, transitory ischemic attacks, and microcirculatory obstructions, indicative of circulatory disturbances. To investigate the presence of microcirculatory disorders without the confounding effect of treatments, we used -thalassemic mice with typical clinical characteristics of human -thalassemia major. One impediment to the understanding of microcirculatory physiology, in particular for -thalassemic mice, has been the lack of an appropriate noninvasive imaging approach. We thus developed a novel noninva-sive high-frequency ultrasound imaging method to evaluate murine vascular hemodynamic properties. In our -thalassemic mice, total peripheral vascular resistance was significantly increased (P 0.01) compared with wildtype littermates, whereas mean blood pressure