Atrial natriuretic factor prevents NaCl-sensitive hypertension in spontaneously hypertensive rats.
Our previous studies demonstrated that acute infusion of atrial natriuretic factor (ANF) produces an enhanced depressor response in NaCl-sensitive spontaneously hypertensive rats (SHR-S) fed a high (8%) NaCl diet compared with control SHR-S fed a normal (1%) NaCl diet and that dietary NaCl loading increases circulating ANF levels in Wistar-Kyoto (WKY) rats but not in SHR-S. The current study tested the hypotheses that 1) long-term infusion of ANF at a dose that elevates plasma ANF to levels comparable with those seen in high NaCl-fed WKY rats prevents the NaCl-induced exacerbation of hypertension in SHR-S and 2) ANF lowers blood pressure in this model by a sympatholytic effect. Male SHR-S received infusions of ANF (0.1 microgram/hr) or vehicle intravenously via osmotic minipump for 3 weeks beginning immediately before initiation of 1% or 8% NaCl diets at age 7 weeks. Chronic ANF infusion prevented the increase in arterial pressure in response to a high NaCl diet in SHR-S but had no effect in 1% NaCl-fed SHR-S. Thus, the NaCl-sensitive component of hypertension in SHR-S was more sensitive to ANF than the non-NaCl-sensitive component. Plasma norepinephrine was significantly increased in ANF-treated, 8% NaCl-fed SHR-S compared with vehicle controls, suggesting that ANF did not prevent NaCl-sensitive hypertension by a sympatholytic effect.(ABSTRACT TRUNCATED AT 250 WORDS)
Jin
H K
HK
Department of Medicine, University of Alabama, Birmingham 35294.
Yang
R H
RH
Chen
Y F
YF
Oparil
S
S
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D002395:Catecholamines / Q000097:blood; D004032:Diet; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D012965:Sodium Chloride / Q000494:pharmacology*
D002395:Catecholamines; D012965:Sodium Chloride; D009320:Atrial Natriuretic Factor