Sympathoinhibitory effects of atrial natriuretic peptide in rats with heart failure.
BACKGROUND
It has been suggested that a blunted sympathoinhibitory response to atrial natriuretic peptide (ANP) may contribute to the elevation of sympathetic activity seen in heart failure.


RESULTS
Experiments were performed in anesthetized rats 6 to 9 weeks after coronary ligation to induce heart failure. Responses to intravenous injections of ANP (4 microg/kg) did not differ between the sham-operated (n = 11) and heart-failure (n = 7) rats. Before sinoaortic denervation, ANP decreased mean arterial pressure (MAP) by 8 mm Hg in both the heart-failure and sham rats, renal sympathetic nerve activity (RSNA) by 9% to 10% in both groups, and heart rate (HR) by 12 to 13 beats/min in both groups. After baroreceptor denervation, ANP decreased MAP by approximately 22 mm Hg, RSNA by 14%, and HR by 16 beats/min in both the heart-failure and sham rats. After vagotomy, there was no longer a significant decrease in RSNA or HR in response to ANP.


CONCLUSIONS
The sympathoinhibitory effects of ANP are maintained in heart failure. This suggests that the elevated sympathetic activity observed in heart failure cannot be attributed to a blunting of the response to ANP.
Barrett
C J
CJ
Department of Physiology and Biophysics, University of Nebraska College of Medicine, Nebraska Medical Center, Omaha 68198-4575, USA.
Schultz
H D
HD
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000008:administration & dosage* / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D004195:Disease Models, Animal; D006333:Heart Failure / Q000188:drug therapy* / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects*; D007275:Injections, Intravenous; D007668:Kidney / Q000293:injuries*; D016014:Linear Models; D008297:Male; D011336:Probability; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D013564:Sympathetic Nervous System / Q000187:drug effects* / Q000503:physiopathology*; D014628:Vagotomy
D009320:Atrial Natriuretic Factor