NATRIURETIC PEPTIDES IN SHEEP WITH PRESSURE-OVERLOAD LEFT-VENTRICULARHYPERTROPHY

To examine tissue and plasma atrial (ANP) and brain natriuretic peptid e (BNP) responses to left ventricular hypertrophy (LVH) 7 sheep underw ent suprarenal aortic banding (20mmHg initial pressure differential). Median survival time was 15 days. Proximal mean aortic pressure (MAP) increased from 65.1+/-5.0mmHg (baseline) to 111.6+/-7.5mmHg (day 7, p< 0.0001). Distal systolic aortic pressure fell from 85.5+/-8.7mmHg (bas eline) to 55.6+/-6.4mmHg (day 7, p=0.0002). Maximal plasma ANP (26.9+/ -3.6 vs. 101.1+/-1.2pmol/L, p=0.005) and BNP (15.3+/-3.6 vs. 3.5+/-1.0 pmol/L, p=0.006) were recorded at 15+/-4.0 days. Coarctation induced r apid increases in PRA and plasma aldosterone and a fall in urinary sod ium. Post-mortem examination of hearts confirmed LVH. Compared with co ntrols, tissue ANP concentration was reduced in left atrium (p=0.04) a nd LV (p=0.04). BNP concentration was reduced in left atrium (p=0.02) but tended to be higher in I,ri. In conclusion, suprarenal aortic coar ctation leads to progressive hypertension resulting in LVH, progressiv e increases in plasma ANP and BNP and, in most cases, death from heart failure.