Vascular Adaptations to Transverse Aortic Banding in Mice.

摘要

Transverse aortic banding in mice generates pressure overload, but cardiac hypertrophy is variable, and the effects on peripheral hemodynamics are unknown. The purpose of this study was to characterize and model carotid and aortic blood flow patterns in banded mice using noninvasive Doppler methods. In 15 normal mice a 27-gauge needle was sutured against the transverse aorta and then removed. In 6 sham-operated mice the suture was not tied. A Doppler probe was used to measure right (R) and left (L) carotid artery (CA), aortic, and mitral blood velocity 1 day later. At 7 days the heart-weight/body-weight ratio (HW/BW) was measured. Results showed that mean aortic, mitral, and carotid velocities were similar in sham and banded mice, but peak RCA/LCA velocities were much higher in banded mice and were highly correlated to HW/BW. An esophageal Doppler probe detected high jet velocity and distal vorticity. The authors conclude that mice compensate for the band by increasing right carotid artery resistance and compliance and decreasing left carotid artery resistance to maintain normal cerebral perfusion. Velocity signals measured within one day and fitted to a lumped parameter arterial model to estimate the pressure drop can predict the amount of cardiac hypertrophy at one week.