AJP - Heart and Circulatory Physiology, Vol 250, Issue 5 871-H878, Copyright © 1986 by American Physiological Society
Differing hemodynamic responses to atrial natriuretic factor in two models of hypertension
M. Volpe, R. E. Sosa, F. B. Muller, M. J. Camargo, N. Glorioso, J. H. Laragh, T. Maack and S. A. Atlas
Hemodynamic responses to synthetic atrial natriuretic factor (ANF), were
studied in renin-dependent two-kidney, one-clip (2K,1C) and
deoxycorticosterone (DOC) salt-treated hypertensive rats as well as
normotensive controls. ANF infusion (800 pmol/kg prime, 120 pmol X kg-1 X
min-1 for 60 min) decreased blood pressure (BP) more in conscious 2K,1C
(-24 +/- 4%) than in DOC salt-treated (-12 +/- 4%, P less than 0.05) or
control rats. Hemodynamic parameters were also evaluated during graded
infusion of three doses, each for 30 min. At 24 and 120 pmol X kg-1 X
min-1, ANF lowered BP in 2K,1C rats, both conscious (from 156 +/- 6 to 144
+/- 7, P less than 0.05 and 135 +/- 5 mmHg, P less than 0.05) and
anesthetized (from 148 +/- 7 to 138 +/- 7, P less than 0.05 and 128 +/- 7,
P less than 0.05). In anesthetized 2K,1C, BP changes were associated with
reduction in total peripheral resistance (TPR) that became significant at
120 pmol X kg-1 X min-1 (-10 +/- 2%), whereas cardiac output (CO) and
stroke volume (SV) were unchanged. In DOC-salt-treated rats these doses did
not lower BP despite progressive falls in CO (-7 +/- 3% and -24 +/- 5%, P
less than 0.05) and SV (-8 +/- 2% and -23 +/- 5%, P less than 0.05), which
were balanced by a simultaneous rise in TPR (+12 +/- 4% and +26 +/- 10%, P
less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
