No effect of L-arginine supplementation on pulmonary endothelial dysfunction after cardiopulmonary bypass.
BACKGROUND
Acetylcholine is an endothelium-dependent vasodilator through the L-arginine-nitric oxide pathway. After ischemia-reperfusion this effect is attenuated, also demonstrated in the pulmonary circulation after cardiopulmonary bypass. Administration of L-arginine has been shown to have a protective effect on endothelial function in reperfusion injury. The aim of the current study was to test the possible effect of L-arginine on the acetylcholine reactivity in the pulmonary circulation after cardiopulmonary bypass.


METHODS
Thirty-five patients with ischemic and/or valvular heart disease were investigated in a randomized, double-blinded, placebo-controlled study. The patients were divided into three groups. Group 1: high dose L-arginine (n=10), group 2: low dose L-arginine (n=10), group 3: placebo, no L-arginine, (n=15). The acetylcholine reactivity was tested with measurements of pulmonary vascular resistance before surgery and 1, 2 and 3-4 h after cardiopulmonary bypass.


RESULTS
After cardiopulmonary bypass an attenuation of the acetylcholine reactivity over time was observed in all groups, with no differences between groups.


CONCLUSIONS
In the current study L-arginine had no protective effect on the pulmonary endothelium after cardiopulmonary bypass, measured as reactivity to an infusion of acetylcholine.
Angdin
M
M
Department of Surgical Sciences, Karolinska Institute, Stockholm, Sweden. 087527848@telia.com
Settergren
G
G
Liska
J
J
Astudillo
R
R
D000109:Acetylcholine / Q000502:physiology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001120:Arginine / Q000097:blood / Q000627:therapeutic use*; D002302:Cardiac Output / Q000187:drug effects; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011652:Pulmonary Circulation / Q000187:drug effects*; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects
D001120:Arginine; D000109:Acetylcholine