A method for continuously assessing coronary blood flow velocity in the rat

We have developed a directional pulsed-Doppler system to make blood flow velocity measurements in the coronary arteries of the rat. The probe consists of a 1-mm2 crystal mounted in a 6-mm suction cup, which can be attached by vacuum to the vessel without requiring dissection. Recordings of phasic coronary blood flow velocity (CBV) in the rat indicate that 82 +/- 2% (mean +/- SE) of the area under the CBV recording occurs in diastole. CBV increased during an infusion of dipyridamole and changed in parallel with alterations in left-ventricular pressure. To validate the technique we correlated changes in CBV wih changes in microsphere-measured left-ventricular perfusion (range, 20—;780 ml/min x 100 g). These two methods of estimating coronary flow correlated closely (r = 0.93). Measurements of phasic CBV in the rat with this Doppler system should permit a detailed characterization of the coronary circulation in many models of disease that have been developed in the rat.

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Systolic Wall Stress May Affect the Intramural Coronary Blood Flow Velocity in Myocardial Hypertrophy, Independently on the Left Ventricular Mass

Echocardiography ◽

10.1111/j.1540-8175.2005.40093.x ◽

2005 ◽

Vol 22 (8) ◽

pp. 642-648 ◽

Cited By ~ 4

Author(s):

Cesare De Gregorio ◽

Antonio Micari ◽

Gianluca Di Bella ◽

Scipione Carerj ◽

Sebastiano Coglitore

Keyword(s):

Blood Flow ◽

Flow Velocity ◽

Left Ventricular Mass ◽

Coronary Blood Flow ◽

Blood Flow Velocity ◽

Myocardial Hypertrophy ◽

Wall Stress ◽

Left Ventricular ◽

Systolic Wall Stress ◽

Coronary Blood Flow Velocity

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Measurement of coronary blood flow velocity in conscious rats

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1994.266.2.h840 ◽

1994 ◽

Vol 266 (2) ◽

pp. H840-H845

Author(s):

L. F. Jones ◽

S. K. Landas ◽

A. K. Johnson

Keyword(s):

Blood Flow ◽

Flow Velocity ◽

Coronary Blood Flow ◽

Blood Flow Velocity ◽

Cardiac Tissue ◽

Heart Weight ◽

Pulsed Doppler ◽

Conscious Rats ◽

Suction Cup ◽

Coronary Blood Flow Velocity

This study describes a technique for the continuous recording of coronary blood flow velocity (CBV) in conscious unrestrained rats. A pulsed Doppler flow probe consisting of a 1-mm2 crystal mounted in a 4-mm suction cup was positioned over the left coronary artery of pentobarbital sodium-anesthetized rats. The probe was held in place with mild suction and sutured to the surface of the myocardium. Probes were connected to a pulsed Doppler flowmeter, which measures Doppler shift and provides an index of blood flow velocity. While rats were still anesthetized, the measurement of CBV was validated by determining that CBV peaked during diastole and increased in parallel with arterial pressure. Phasic CBV signals obtained in conscious rats were similar to those observed in anesthetized animals. Intravenous infusion of dipyridamole (0.5–3 mg.kg-1 x mg-1) produced a dose-dependent increase in CBV and decrease in coronary vascular resistance in conscious unrestrained rats 7 days after placement of the probe. Light microscopic review of cardiac tissue from instrumented rats revealed minimal epicardial reaction (fibrin deposition) restricted to the immediate area of the probe without distortion of the coronary architecture, edema, inflammation, or necrosis compared with controls. Heart weight-to-body weight ratios of instrumented rats were also not different from those of control rats. This study describes the first technique by which CBV can be measured continuously in chronically instrumented rats.

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