Effect of ischaemia and reperfusion on the intracellular concentration of taurine and glutamine in the hearts of patients undergoing coronary artery surgery.
Level 3 - non-randomized controlled study
Non-randomized comparative clinical cohort study
PubMed 9092709 · doi:10.1016/s0005-2736(96)00225-8
What was done
Intracellular taurine and glutamine concentrations were measured in the hearts of patients undergoing coronary artery bypass surgery during 30 minutes of ischemic arrest and after 20 minutes of normothermic reperfusion. The study compared patients receiving cold crystalloid cardioplegic solution (n = 19) versus cold blood cardioplegic solution (n = 16), along with measurements of tissue ATP and lactate.
What was found
In the cold crystalloid group (n = 19), 30 minutes of ischemic arrest reduced taurine from 9.8 +/- 0.8 to 7.7 +/- 0.7 micromol/g wet weight (P < 0.05) and glutamine from 8.7 +/- 0.5 to 7.2 +/- 0.6 micromol/g wet weight; after 20 minutes of reperfusion, values remained depressed at 7.5 +/- 0.5 for taurine and 7.4 +/- 0.7 for glutamine. In the cold blood cardioplegia group (n = 16), ischemic arrest did not cause a significant decrease, but reperfusion caused a marked fall in taurine (9.4 +/- 0.5 to 6.5 +/- 0.7 micromol/g wet weight) and glutamine (8.0 +/- 0.7 to 5.8 +/- 0.4 micromol/g wet weight). The amino acid decreases were accompanied by reduced ATP and increased tissue lactate.
Why it matters
The findings demonstrate that cardiopulmonary bypass with cardioplegic arrest leads to significant myocardial depletion of taurine and glutamine, with blood cardioplegia delaying but not preventing reperfusion-associated loss.
Limits
The sample size is small (35 patients total). Allocation between cardioplegia types was not randomized, and clinical recovery or postoperative cardiac function was not correlated with the observed biochemical depletion. Precise statistical values for all endpoints were not provided in the abstract.
Cited by
- supports Taurine is one of the most abundant free amino acids in human heart muscle.