Assessment of subrenal banding of the abdominal aorta as a method of inducing cardiac hypertrophy in the guinea pig.

Abstract

The aims of this study were to develop a model of left ventricular hypertrophy in the guinea pig using the technique of aortic banding below the level of the renal arteries, and to characterize any cardiac electrophysiological changes induced. Female guinea-pigs were either sham operated or the abdominal aorta was partially occluded by banding around a 23 or 25 G needle. Following recovery, animals were monitored for 10 weeks. The left ventricular dry weight to body weight ratio was similar in sham (0.326 +/- 0.01 mg/g, n = 12) and aortic banded guinea pigs (0.308 +/- 0.1 mg/g, n = 11). Conscious mean arterial blood pressure was also not modified by the aortic banding 10 weeks after operation (72 +/- 16 (sham) vs 71 +/- 1 mmHg). The action potential characteristics measured in isolated superfused left papillary muscle stimulated at 1 Hz were similar in sham and aortic banded groups. The action potential duration measured at 50 and 90% of repolarization tended to be longer in muscle from aortic banded (122.4 +/- 10 ms ADP50 and 155.2 +/- 9.5 ms APD90) than sham operated animals (105.8 +/- 8.4 and 142.2 +/- 6.2 ms) but these differences were not statistically significant. Hypoxia abbreviated the cardiac action potential to a similar degree in muscle from sham and aortic banded animals. It is concluded that sub-renal aortic banding with a 23 or 25G needle fails to develop left ventricular hypertrophy in the guinea pig 10 weeks after operation.