Neutralization of proANP (1-30) exacerbates hypertension in the spontaneously hypertensive rat.
1. The aim of the present studies was to determine the role of proANP (1-30) in the regulation of arterial pressure. It was hypothesized that blocking endogenous proANP (1-30) would exacerbate the hypertension in susceptible animal models. 2. Pentobarbital-anaesthetized spontaneously hypertensive rats (SHR) were pretreated i.v. with 1.2 mL rabbit serum containing an antibody directed specifically against rat proANP (1-30) (SHR-AB group; n = 7) or an equal volume of normal rabbit serum as a control (SHR-NRS group; n = 5). 3. Following a 1 h equilibration period and two 30 min baseline periods, rats were volume expanded with 3 mL of 6% albumin in Krebs' solution and observed for an additional 3 h to determine the effects of the anti-proANP on arterial pressure. 4. Arterial pressure increased in both groups compared with their own baselines with volume expansion, but was significantly greater in the anti-proANP SHR group compared with the SHR-NRS group throughout the volume expansion period. A maximum difference of 21 mmHg between the anti-proANP SHR group and the NRS-SHR group was observed at 150 min of the study (183 +/- 5 vs 162 +/- 3 mmHg, respectively; P < 0.005. 5. These results suggest a protective role for proANP (1-30) in the SHR model of hypertension.
Dietz
John R
JR
Department of Physiology and Biophysics, University of South Florida College of Medicine, Box 8, Tampa, FL 33612, USA. jdietz@hsc.usf.edu
Vesely
David L
DL
Gower
William R
WR
Landon
Carol S
CS
Lee
Sook Jeong
SJ
Nazian
Stanley J
SJ
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D009320:Atrial Natriuretic Factor / Q000037:antagonists & inhibitors* / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D010446:Peptide Fragments / Q000037:antagonists & inhibitors* / Q000502:physiology*; D011498:Protein Precursors / Q000037:antagonists & inhibitors* / Q000502:physiology*; D051381:Rats; D011918:Rats, Inbred SHR
D000906:Antibodies; D010446:Peptide Fragments; D011498:Protein Precursors; C054547:atrial natriuretic factor prohormone (1-30), human; D009320:Atrial Natriuretic Factor