Supplementation with L-glycyl-L-glutamine improves functional recovery following ischaemia reperfusion in the isolated rat heart

The amino acids, glycine and glutamine have been implicated in myocardial protection against ischaemia reperfusion. This study investigated whether such protection could be enhanced by simultaneously delivering these amino acids as the dipeptide, L-glycyl-Lglutamine (gly-gln). Hearts from 36 week-old male Wistar rats were perfused in the Langendorff mode. For measurements of functional performance and reperfusion damage the perfusion protocol comprised 20 min' baseline perfusion, 40 min' global normothermic ischaemia and 40 min' reperfusion. In separate experiments small biopsy samples of the left ventricle were collected at the beginning and end of ischaemia for lactate measurements and from the right ventricle at the end of ischaemia for measurement of thiobarbituric acid reactive substances (TBARs). Where used, 2 mM gly-gln was added to the perfusate 10 min into baseline perfusion and was washed after 10 min' reperfusion. Data presented are means ± SE of n = 7 and were compared using student's unpaired T tests. The presence of 2 mM gly-gln significantly improved the recovery of left ventricular developed pressure from 18.49 ± 3.01 to 33.9 ± 4.85 % (p