Intralymphocytic sodium and free calcium concentration in relation to salt sensitivity in patients with essential hypertension.
In order to clarify the relation between salt sensitivity and changes in intracellular sodium ([Na]i) and free calcium concentration ([Ca2+]i) after salt loading, [Na]i and [Ca2+]i were determined in lymphocytes of twenty patients with essential hypertension under a low salt diet (3 g/day) and a high salt diet (20 g/day) for seven days, respectively. They were classified as "salt-sensitive" (n = 10) or "nonsalt-sensitive" (n = 10) on the basis of the changes in blood pressure after salt loading. Both lymphocytic [Na]i and [Ca2+]i were significantly increased with salt loading in salt-sensitive patients (p less than 0.05 for both), while they were not affected by salt loading in nonsalt-sensitive patients. Lymphocytic [Ca2+]i showed a positive correlation with lymphocytic [Na]i under both low salt diet (r = 0.62, p less than 0.01) and high salt diet (r = 0.70, p less than 0.01) in all patients in both groups. In addition, a close and positive correlation was observed between the changes in lymphocytic [Na]i and those in lymphocytic [Ca2+]i after salt loading in all patients in both groups (r = 0.80, p less than 0.001). These results suggest that the increase in [Ca2+]i, possibly linked with the increase in [Na]i, may be involved in elevation of blood pressure in the salt-sensitive patients after salt loading.
Oshima
T
T
First Department of Internal Medicine, Hiroshima University School of Medicine, Japan.
Matsuura
H
H
Kido
K
K
Matsumoto
K
K
Otsuki
T
T
Fujii
H
H
Masaoka
S
S
Okamoto
M
M
Tsuchioka
Y
Y
Kajiyama
G
G
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002118:Calcium / Q000032:analysis* / Q000378:metabolism; D004039:Diet, Sodium-Restricted; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology* / Q000628:therapy; D008214:Lymphocytes / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D012964:Sodium / Q000032:analysis* / Q000378:metabolism; D012982:Sodium, Dietary / Q000008:administration & dosage* / Q000493:pharmacokinetics
D012982:Sodium, Dietary; D012964:Sodium; D002118:Calcium