11703
document
Acute intravenous L-arginine infusion decreases endothelin-1 levels and improves endothelial function in patients with angina pectoris and normal coronary arteriograms : correlation with asymmetric dimethylarginine levels . BACKGROUND We tested the hypothesis that asymmetric dimethylarginine ( ADMA ) levels could be elevated and influence endothelin-1 and nitric oxide release and action in patients with cardiac syndrome X ( CSX ) . In addition , we evaluated whether an intravenous infusion of L-arginine would improve endothelial function in these subjects . METHODS AND RESULTS Nine patients with CSX and 14 control subjects underwent a continuous infusion of L-arginine ( 0.125 g/min ) or saline for 120 minutes . Sixty minutes after L-arginine or saline infusions , an intravenous insulin bolus ( 0.1 U/kg ) combined with a euglycemic clamp was performed . Basal ADMA and endothelin-1 levels were higher in patients with CSX than in controls . At the end of the first hour of infusion , compared with saline , L-arginine infusion increased basal forearm blood flow , nitrite and nitrate ( NOx ) , and forearm cGMP release and decreased endothelin-1 . After insulin bolus , during saline , insulin-induced NOx , endothelin-1 , and forearm cGMP release was almost abolished . Conversely , L-arginine restored a physiological profile of all endothelial variables compared with control subjects . In control subjects , compared with saline infusion , L-arginine infusion did not modify any parameter . ADMA levels were positively correlated with basal endothelin-1 levels and negatively correlated with insulin-induced incremental levels of NOx and forearm cGMP release . CONCLUSIONS Plasma ADMA levels are increased in patients with CSX , and they are correlated with increases in endothelin-1 and reductions in insulin-induced increments in plasma NOx and cGMP , effects that are reversed by intravenous L-arginine . These data suggest that increased ADMA levels play a role in the abnormal vascular reactivity that is observed in patients with CSX .
11704
Intervention_Pharmacological
Acute intravenous L-arginine infusion
11705
Intervention_Pharmacological
asymmetric dimethylarginine
11706
Intervention_Pharmacological
endothelin-1
11707
Intervention_Pharmacological
nitric oxide
11708
Intervention_Pharmacological
L-arginine
11709
Intervention_Pharmacological
L-arginine ( 0.125 g/min ) or saline
11710
Intervention_Pharmacological
L-arginine
11711
Intervention_Pharmacological
saline infusions
11712
Intervention_Pharmacological
insulin
11713
Intervention_Other
euglycemic clamp
11714
Intervention_Pharmacological
saline
11715
Intervention_Pharmacological
L-arginine
11716
Intervention_Pharmacological
saline infusion
11717
Intervention_Pharmacological
L-arginine infusion
11718
Outcome_Physical
endothelin-1 levels
11719
Outcome_Physical
endothelial function
11720
Outcome_Physical
dimethylarginine levels .
11721
Outcome_Physical
asymmetric dimethylarginine ( ADMA ) levels
11722
Outcome_Physical
endothelin-1
11723
Outcome_Physical
nitric oxide release and action
11724
Outcome_Physical
endothelial function
11725
Outcome_Physical
Basal ADMA
11726
Outcome_Physical
endothelin-1 levels
11727
Outcome_Physical
basal forearm blood flow
11728
Outcome_Physical
nitrite and nitrate ( NOx )
11729
Outcome_Physical
forearm cGMP
11730
Outcome_Physical
endothelin-1
11731
Outcome_Physical
insulin-induced NOx
11732
Outcome_Physical
endothelin-1
11733
Outcome_Physical
forearm cGMP
11734
Outcome_Other
endothelial variables
11735
Outcome_Physical
ADMA levels
11736
Outcome_Physical
endothelin-1 levels
11737
Outcome_Physical
levels of NOx
11738
Outcome_Physical
forearm cGMP
11739
Outcome_Physical
Plasma ADMA levels
11740
Outcome_Physical
endothelin-1
11741
Outcome_Physical
NOx
11742
Outcome_Physical
cGMP
11743
Outcome_Physical
ADMA levels
11744
Participant_Condition
angina pectoris
11745
Participant_Condition
arteriograms
11746
Participant_Condition
cardiac syndrome X
11747
Participant_Sample-size
Nine