Abstract | OBJECTIVES: METHODS: RESULTS: Compared with the protection afforded by blood cardioplegic solution without L-arginine (group 1), the addition of a 4 mmol/L concentration of L-arginine (group 2) significantly improved myocardial protection, resulting in complete return of systolic function (end-systolic elastance 38% vs 100%; P <.001 vs 4 mmol/L L-arginine) and preload recruitable stroke work (40% vs 100%; P <. 001 vs 4 mmol/L L-arginine); minimal increase in diastolic stiffness (239% vs 158%; P <.001 vs 4 mmol/L L-arginine); and lower coronary vascular resistance, conjugated diene production, and myeloperoxidase activity (P <.001 vs 4 mmol/L L-arginine in each case). Conversely, supplementing the cardioplegic solution with a 10 mmol/L dose of L-arginine (group 3) negated these beneficial effects, resulting in depressed systolic function (end-systolic elastance 41% +/- 2%; P <.001 vs 4 mmol/L L-arginine) and preload recruitable stroke work (40% +/- 2%; P <.001 vs 4 mmol/L L-arginine); increased diastolic stiffness (246% +/- 7%; P <.001 vs 4 mmol/L L-arginine); and higher conjugated diene production, myeloperoxidase activity, and coronary vascular resistance (P <.001 vs 4 mmol/L L-arginine in each case). CONCLUSIONS: Enriching cardioplegic solution with a 4 mmol/L concentration of L-arginine significantly improves myocardial protection by reducing oxygen-derived free radical formation by white blood cells, thus preserving vascular and myocardial function. However, these beneficial effects are dose dependent because 10 mmol/L concentrations of L-arginine increase oxygen-derived free radical production, resulting in vascular and myocardial dysfunction.
|
Authors | M T Kronon, B S Allen, A Halldorsson, S Rahman, T Wang, M Ilbawi |
Journal | The Journal of thoracic and cardiovascular surgery
(J Thorac Cardiovasc Surg)
Vol. 118
Issue 4
Pg. 655-64
(Oct 1999)
ISSN: 0022-5223 [Print] United States |
PMID | 10504630
(Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
|
Chemical References |
- Cardioplegic Solutions
- Free Radical Scavengers
- Nitrates
- Oxidants
- Vasodilator Agents
- peroxynitric acid
- Nitric Oxide
- Arginine
- Peroxidase
|
Topics |
- Animals
- Animals, Newborn
- Arginine
(administration & dosage, therapeutic use)
- Blood
- Blood Pressure
(drug effects)
- Cardiac Volume
(drug effects)
- Cardioplegic Solutions
(administration & dosage, therapeutic use)
- Cardiopulmonary Bypass
- Coronary Vessels
(drug effects)
- Diastole
- Dose-Response Relationship, Drug
- Free Radical Scavengers
(metabolism)
- Heart
(drug effects, physiopathology)
- Hypoxia
(physiopathology)
- Leukocytes
(drug effects, metabolism)
- Nitrates
(metabolism)
- Nitric Oxide
(biosynthesis, metabolism)
- Oxidants
(metabolism)
- Peroxidase
(drug effects)
- Stress, Physiological
(physiopathology)
- Stroke Volume
(drug effects)
- Swine
- Systole
- Vascular Resistance
(drug effects)
- Vasodilator Agents
(metabolism)
|