The occurrence of parathyroid hypertensive factor (PHF) in Dahl rats.
Parathyroid hypertensive factor (PHF) is a newly described circulating hypertensive factor which is present in genetic hypertensive rat models, and which has been associated with salt sensitivity in essential hypertensive patients. To determine if Dahl-S or -R rats differentially express PHF-like activity, and whether such PHF levels might be affected by salt intake, we placed 5-week-old Dahl-S and Dahl-R rats on one of three diets: low salt (< 0.04%), normal salt (0.7%), or high salt (8%). After 8 weeks on the respective diets, mean arterial pressure was measured and plasma obtained for PHF analysis. Mean arterial pressures of Dahl-R rats were not different despite varying salt intakes. Mean arterial pressures of Dahl-S rats on normal and high salt diets, but not on the low salt diet, were significantly higher than those of Dahl-R rats on the same diet. PHF-like activity was not detectable in Dahl-R rats at any level of salt intake. In Dahl-S rats, no PHF activity was detectable in rats on the low salt diet, but in rats on the normal and high salt diets, significant PHF-like activity was detectable (9.5 +/- 2 mm Hg and 14.2 +/- 2 mm Hg, respectively, P < .001 in both cases). For all Dahl-S rats together, PHF levels correlated with mean arterial pressure (r = 0.50, P = .0077). These results show that Dahl-S rats are capable of expressing PHF-like activity, which is induced by increasing dietary salt intakes.(ABSTRACT TRUNCATED AT 250 WORDS)
Lewanczuk
R Z
RZ
Department of Physiology, University of Alberta, Edmonton, Canada.
Pang
P K
PK
D000818:Animals; D001685:Biological Factors / Q000097:blood*; D001794:Blood Pressure / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D004032:Diet; D004039:Diet, Sodium-Restricted; D006973:Hypertension / Q000097:blood* / Q000235:genetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D017207:Rats, Sprague-Dawley; D012982:Sodium, Dietary / Q000494:pharmacology
D001685:Biological Factors; D012982:Sodium, Dietary; C064505:parathyroid hypertensive factor