Is glutamine beneficial in ischemic heart disease?
OBJECTIVE
Glutamine enhances recovery from acute normothermic ischemia in isolated rat heart by a dose-dependent effect (Khogali et al. J Mol Cell Cardiol 1998;30:819). We compared the cardioprotective effects of equimolar concentrations of glutamine, glutamate, and aspartate in isolated rat heart. We also explored the potential cardioprotective effects of glutamine in patients with chronic stable angina.


METHODS
The isolated perfused working rat heart was subjected to ischemia, followed by reperfusion with or without an amino acid (2.5 mM). Patients with chronic stable angina received a single oral dose of glutamine (80 mg/kg) or placebo in a double-blind, random fashion 40 min before a standard Bruce exercise test.


RESULTS
Postischemic reperfusion of isolated rat heart with glutamine (but not with glutamate or aspartate) resulted in full recovery of cardiac output. Only glutamine prevented the decrease in the myocardial ratio between adenosine triphosphate to adenosine diphosphate and significantly enhanced the myocardial ratio of reduced to oxidized glutathione. A single oral dose of glutamine given to patients with chronic stable angina significantly increased plasma glutamine concentration from 419 to 649 microM and delayed time to onset of more than 1.0 mm of ST segment depression on the ECG by 38 s.


CONCLUSIONS
Glutamine may be cardioprotective in patients with coronary heart disease.
Khogali
Shihab E O
SE
Department of Cardiology, Ninewells Hospital and Medical School, Dundee, United Kingdom. s.e.o.khogali@dundee.ac.uk
Pringle
Stuart D
SD
Weryk
Brian V
BV
Rennie
Michael J
MJ
D000244:Adenosine Diphosphate / Q000032:analysis; D000255:Adenosine Triphosphate / Q000032:analysis; D000284:Administration, Oral; D000368:Aged; D000787:Angina Pectoris / Q000188:drug therapy / Q000517:prevention & control*; D000818:Animals; D001224:Aspartic Acid / Q000008:administration & dosage / Q000627:therapeutic use; D002302:Cardiac Output / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004341:Drug Evaluation; D005080:Exercise Test; D018698:Glutamic Acid / Q000008:administration & dosage / Q000627:therapeutic use; D005973:Glutamine / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D005978:Glutathione / Q000032:analysis; D006321:Heart / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000188:drug therapy / Q000517:prevention & control*; D015425:Myocardial Reperfusion / Q000379:methods; D009206:Myocardium / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D005973:Glutamine; D001224:Aspartic Acid; D018698:Glutamic Acid; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D005978:Glutathione