AJP - Heart and Circulatory Physiology, Vol 253, Issue 6 1623-H1627, Copyright © 1987 by American Physiological Society
Atrial natriuretic factor in dogs with one-kidney, one-clip Goldblatt hypertension
K. M. Verburg, R. H. Freeman, D. Villarreal and M. W. Brands
Department of Physiology, University of Missouri, School of Medicine, Columbia 65212.
The temporal changes in the plasma concentration of immunoreactive atrial
natriuretic factor (ANF) were studied in dogs (n = 5) before and after
renal artery constriction to produce one-kidney, one-clip renovascular
hypertension. Three days after renal artery constriction, circulating ANF
increased from 34 +/- 7 to 344 +/- 129 pg/ml (P less than 0.05) in
association with a 38-mmHg elevation of mean arterial pressure and
increases in plasma renin and aldosterone levels. Plasma renin and
aldosterone remained elevated for 9 days after renal artery constriction.
Arterial pressure stabilized at this elevated level of 35-40 mmHg above
base line for the duration of the 4 wk after renal artery constriction.
Right atrial filling pressure did not change significantly (P greater than
0.05) after constriction of the renal artery. This observation suggests
that volume expansion with right atrial distention is not the only stimulus
for release of ANF in these hypertensive dogs. Plasma ANF remained
significantly elevated above base-line levels for 7 days postconstriction
even though a twofold decrease from the maximal response of 344 +/- 129
pg/ml on day 3 to 168 +/- 48 pg/ml on day 7 was observed during this same
time interval. Plasma ANF continued to decrease toward prehypertensive
levels throughout the remainder of the established phase of the
hypertension lasting an additional 21 days of observation. The mechanisms
for this observed pattern of plasma ANF are unclear but may involve changes
in left atrial distention and stretch as a stimulus for hormone secretion
with progression of the hypertension.
