Parathyroid hypertensive factor is present in DOCA-salt but not two-kidney-one-clip hypertensive rats

In order to determine whether the expression of parathyroid hypertensive factor (PHF) is secondary to hypertension or whether it is specifically related to low-renin hypertension, PHF levels were measured in DOCA-salt and two-kidney-one-clip (2K-1C) hypertensive rats. Despite equivalent elevations of blood pressure, PHF was detected in the DOCA-salt rats, but not in the 2K-1C rats (17.5 +/- 3.1 mm Hg, P less than .0001 v 0.9 +/- 2.8 mm Hg, P = NS, respectively). Moreover, PHF levels correlated with mean arterial pressure in the DOCA-salt group (r = 0.91, P less than .0001). We conclude that PHF expression is not a secondary phenomenon caused by hypertension, but rather may be causally related to the development of low-renin forms of hypertension.