title: Impairment of endothelial function in salt-sensitive hypertension in humans.
abstract: In this study, we evaluated the relationship between the endothelium-dependent vasodilation and salt sensitivity in patients with essential hypertension. Fifteen untreated hypertensive male patients (age, 29 to 54 years) were sodium restricted (5 g/day) for 1 week, and placed on a high salt diet (20 g/day) the second week. At the end of each period, measurements of forearm vascular responses to drugs (acetylcholine, 3 to 24 microg/min; sodium nitroprusside, 0.15 to 1.2 microg/min; norepinephrine, 0.15 to 1.2 microg/min; and N(G)-monomethyl-L-arginine [L-NMMA], 1 to 8 micromol/min) were obtained by using strain-gauge venous plethysmography. Subjects were divided into two groups according to the blood pressure response to sodium loading: salt-sensitive hypertensive group (24-h mean increase of arterial pressure > or = 10%; n = 6) and salt-resistant group (< 10%; n = 9). The two groups showed no significant difference in clinical data or mean arterial pressure during low salt intake. The dose-dependent vasodilation induced by acetylcholine was significantly reduced (P < .05) in the salt-sensitive hypertensive patients v the salt-resistant patients regardless of sodium loading. There were no differences between the two groups in response to sodium nitroprusside, norepinephrine, or L-NMMA. These results indicate that vasodilation to acetylcholine is reduced in salt-sensitive hypertensive patients even on restricted sodium diets. This may contribute to blood pressure elevation when sodium intake is increased.
authors.affiliation: The First Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Miyoshi
authors.forename: H
authors.initials: H
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Fujiwara
authors.forename: M
authors.initials: M
authors.lastname: Masai
authors.forename: T
authors.initials: T
authors.lastname: Iwasaki
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D004730:Endothelium, Vascular / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009599:Nitroprusside / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D012039:Regional Blood Flow / Q000187:drug effects; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage*; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D017673:Sodium Chloride, Dietary; D009599:Nitroprusside; D019323:omega-N-Methylarginine; D000109:Acetylcholine; D009638:Norepinephrine