Na+/H+ exchange during an oral glucose challenge in patients with essential hypertension.
To determine the effects of an oral glucose challenge on cellular Na+/H+ exchange in vivo we measured plasma glucose concentrations, plasma insulin concentrations, plasma C-peptide concentrations, arterial blood pressure, cytosolic pH (pHi) and cellular Na+/H+ exchange in 24 patients with essential hypertension (HT) and 41 age-matched healthy normotensive control subjects (NT) during a standardized oral glucose tolerance test. Under resting conditions, the plasma glucose concentrations, plasma insulin concentrations, plasma C-peptide concentrations and Na+/H+ exchange activity were significantly higher in HT compared with NT (P < 0.05 in each case). A significant increase in lymphocytic Na+/H+ exchange activity was only seen in NT (resting 0 h: (4.23 +/- 0.2) x 10(-3) pHi/s; mean +/- S.E.M.; 1 h after glucose administration: (6.00 +/- 0.56) x 10(-3) pHi/s; 2 h after glucose administration: (6.65 +/- 0.64) x 10(-3) pHi/s; P = 0.0003 by Friedman's two-way ANOVA), but not in HT (resting 0 h: (6.07 +/- 0.36) x 10(-3) pHi/s; 1 h after glucose administration: (6.72 +/- 1.02) x 10(-3) pHi/s; 2 h after glucose administration: (6.71 +/- 0.62) x 10(-3) pHi/s; P = 0.7470). During an oral glucose challenge the systolic (P < 0.0001) and diastolic (P < 0.0001) blood pressure significantly decreased in HT but not in NT. Essential hypertension shows abnormal in vivo regulation of Na+/H+ exchange and blood pressure following oral glucose intake.
Tepel
M
M
Universitätsklinik Marienhospital, Ruhr-Universität-Bochum, Münster, Germany.
Frye
B
B
Burchardt
M
M
Ruhwinkel
J
J
Spieker
C
C
Zidek
W
W
D000704:Analysis of Variance; D001786:Blood Glucose / Q000378:metabolism; D002096:C-Peptide / Q000032:analysis; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000008:administration & dosage*; D005951:Glucose Tolerance Test; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006973:Hypertension / Q000097:blood / Q000378:metabolism*; D007328:Insulin / Q000097:blood; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D017923:Sodium-Hydrogen Exchangers / Q000378:metabolism*; D013997:Time Factors
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D017923:Sodium-Hydrogen Exchangers; D005947:Glucose