Alterations in rat myocardial mechanics under Goldblatt hypertension and experimental aortic stenosis

Left ventricular hypertrophy was induced in young male Wistar rats by unilateral renal artery constriction, either with (Goldblatt I [ = G I]) or without (Goldblatt II [ = G II]) simultaneous contralateral nephrectomy. An average increase in left ventricular weight of 55% and 18% respectively was reached within 4 weeks as compared with controls of the same age. Further increase in ventricular mass up to the 6-month stage was considerably dependent on the degree of inhibition of body growth of the experimental animals. Other rats underwent a stenosis of the Aorta ascendens (AO) with a reduction in diameter to 50%--60% of the original value, whereby a left ventricular hypertrophy of 10%--30% ensued. Isolated trabecular muscle strips of the left ventricle were examined 4, 8 and 24 weeks (G II), 4 and 8 weeks (G I), and 4 and 6 weeks (AO) after operation. Sham operations were performed for all models used.