title: Parathyroid hypertensive factor-like activity in human essential hypertension: relationship to plasma renin activity and dietary salt sensitivity.
abstract: OBJECTIVE
  To determine the clinical relevance of the newly described circulating pressor factor with parathyroid hypertensive factor (PHF)-like activity.
  
  
  METHODS
  Plasma samples were collected from 94 normotensive and 93 essential hypertensive subjects, the latter either previously defined by dietary salt sensitivity (n = 43), or prospectively studied on both low- (< 50 mmol/day) and high-salt (> 200 mmol/day) diets (n = 16).
  
  
  METHODS
  Blood pressure, demographic factors, plasma renin activity (PRA), urinary electrolyte excretion and bioassayable PHF-like activity were determined in the fasted state on basal and altered dietary salt intakes.
  
  
  RESULTS
  Among the normotensive subjects significantly higher PHF-like activity and reciprocally lower PRA values were observed in Black versus Caucasian subjects, particularly among females. In the hypertensive subjects PHF-like activity levels were significantly elevated in the low- (17.1 +/- 1.5 mmHg, n = 34) and normal- (6.7 +/- 1.8 mmHg, n = 36) but not in the high-renin subgroups compared with values in the normotensive subjects (1.6 +/- 1.1 mmHg). Similarly, PHF-like activity values were significantly higher in salt-sensitive than in salt-insensitive hypertensives. Prospectively, PHF-like activity rose significantly with salt loading (4.9 +/- 1.2 to 20.4 +/- 6.2 mmHg) and was positively related (r = 0.648, P < 0.001) to the pressor response to salt.
  
  
  CONCLUSIONS
  Elevated levels of PHF-like activity are characteristic of the low-renin or salt-sensitive state, or both, and may contribute to the hypertensive process. Elevated PHF-like activity levels found in normotensive subjects may presage the development of low-renin, salt-sensitive hypertension.
authors.affiliation: Cardiovascular Center, New York Hospital, Cornell University Medical Center, New York.
authors.forename: L M
authors.initials: LM
authors.lastname: Resnick
authors.forename: R Z
authors.initials: RZ
authors.lastname: Lewanczuk
authors.forename: J H
authors.initials: JH
authors.lastname: Laragh
authors.forename: P K
authors.initials: PK
authors.lastname: Pang
mesh_terms: D001685:Biological Factors / Q000097:blood*; D044383:Black People; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000208:ethnology / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012083:Renin / Q000097:blood*; D012737:Sex Factors; D012982:Sodium, Dietary / Q000008:administration & dosage*; D044465:White People
chemical_list: D001685:Biological Factors; D012982:Sodium, Dietary; C064505:parathyroid hypertensive factor; D012083:Renin