Effect of L-arginine on systemic and renal haemodynamics in salt-sensitive patients with essential hypertension.
In response to a high sodium (Na+) intake, salt-sensitive patients with hypertension retain more Na+ and manifest a greater rise in arterial pressure than salt-resistant patients. Because there is limited information regarding the role of nitric oxide (NO) in salt-sensitivity we examined the effects of L-arginine (500 mg/kg, i.v. for 30 min) on mean arterial pressure and renal haemodynamics in 21 hypertensive and five normotensive African-Americans. At the end of L-arginine infusion mean arterial pressure fell more in salt-sensitive (-11.5 +/- 2.5) than in salt-resistant (-3.7 +/- 1.5 mm Hg) and control subjects (-3.2 +/- 3.8 mm Hg). At the end of L-arginine infusion effective renal plasma flow (ERPF) increased more (P < 0.05) in controls (+108 +/- 13.9 ml/min/1.73 m2) than in salt-resistant (+55 +/- 16.0 ml/min/1.73 m2) and salt-sensitive patients (+22 +/- 21.5 ml/min/1.73 m2). This study has shown that salt-sensitive African-Americans manifest different systemic and renal haemodynamic responses to L-arginine than salt-resistant patients and controls. The fall in mean blood pressure following L-arginine was greater in salt-sensitive than in salt-resistant patients and controls, whereas the increase in ERPF was reduced in salt-sensitive compared to salt-resistant and normal subjects. The data are in keeping with the notion that a defect in NO production may participate to the genesis of blood pressure sensitivity to salt.
Campese
V M
VM
University of Southern California, Los Angeles, USA.
Amar
M
M
Anjali
C
C
Medhat
T
T
Wurgaft
A
A
D000328:Adult; D001120:Arginine / Q000494:pharmacology*; D044383:Black People; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000208:ethnology / Q000378:metabolism / Q000503:physiopathology*; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D012079:Renal Circulation / Q000187:drug effects*; D012965:Sodium Chloride / Q000378:metabolism*; D001741:Black or African American
D012965:Sodium Chloride; D001120:Arginine