title: Intracellular ions in salt-sensitive essential hypertension: possible role of calcium-regulating hormones.
abstract: To study the blood pressure, ionic, and hormonal responses to chronic dietary salt loading, we measured RBC pHi, Mgi, Nai, and Cai, and compared these with serum levels of Ca-io, 1,25-D, and free levels of PHF in salt-sensitive and salt-insensitive essential hypertension subjects on low and high (200 mEq/day less than UNaV less than 50 mEq/day) dietary salt intakes. As a group, salt loading significantly increased diastolic blood pressure (7.6 +/- /3%), Nai (25.5 +/- /8%) and Cai (27.0 +/- /11%), while Mgi (-14.2 +/- 7%) and pHi (-0.03 +/- /0.01 pH units) fell. Significant changes in pHi, Cai, and Mgi occurred only in SS individuals, who also exhibited elevated levels of 1,25-D and of PHF in association with suppression of Ca-io. Altogether, the pressor response to salt was inversely related to the basal pHi (p less than 0.001), and to the degree of salt-induced suppression of Ca-io (p less than 0.001) and Mgi (p less than 0.001), while being directly related to the basal PHF (p less than 0.001) and to the salt-induced stimulation of 1,25-D (p less than 0.005). We hypothesize that elevated levels of 1,25-D and PHF coordinately shift intracellular cation levels and stimulate cellular calcium uptake from the extracellular space. As such, these calcium-regulating hormones may be responsible, at least in part, for salt-sensitive hypertension.
authors.affiliation: Cardiovascular Center New York Hospital-Cornell Medical Center New York.
authors.forename: L M
authors.initials: LM
authors.lastname: Resnick
authors.forename: R K
authors.initials: RK
authors.lastname: Gupta
authors.forename: R Z
authors.initials: RZ
authors.lastname: Lewanczuk
authors.forename: P K
authors.initials: PK
authors.lastname: Pang
authors.forename: J H
authors.initials: JH
authors.lastname: Laragh
mesh_terms: D001685:Biological Factors / Q000502:physiology*; D002117:Calcitriol / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D004573:Electrolytes / Q000378:metabolism*; D006801:Humans; D006973:Hypertension / Q000209:etiology* / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D001685:Biological Factors; D004573:Electrolytes; C064505:parathyroid hypertensive factor; D012965:Sodium Chloride; D002117:Calcitriol; D008274:Magnesium; D002118:Calcium