Assessment of myocardial glutamate requirements early after coronary artery bypass surgery
1998 (English)In: Scandinavian Cardiovascular Journal, ISSN 1401-7431, Vol. 32, no 3, 145-152 p.Article in journal (Refereed) Published
Glutamate is an important substrate for the intermediary metabolism of the heart, particularly in association with ischemia. Early after coronary artery bypass surgery (CABG) myocardial uptake of glutamate seems to be limited by substrate availability (arterial levels). However, glutamate is not an innocuous substrate. As arterial levels of glutamate are important both for myocardial uptake and adverse effects, an attempt was made to determine a minimum dose of glutamate sufficient to supply the needs of the heart after CABG. Ten patients received and infusion of 220-240 ml of 0.1 M L-glutamic acid solution at varying rates during two 30-min periods, starting 2 h after uncomplicated elective CABG. Intravenous glutamate infusion caused a dose-dependent linear increase in arterial glutamate and an increased myocardial uptake of glutamate. However, myocardial uptake of glutamate correlated with arterial levels only at lower infusion rates. Although maximal peak uptake in individual patients (6.6 ± 1.1 μmol/min) occurred at an average increase of arterial whole blood glutamate of 172 ± 34 μmol/L, the greatest impact on myocardial glutamate uptake was achieved by increasing arterial whole blood glutamate by less than 100 μmol/L. This implies that an infusion rate of 30-40 mg glutamate/kg BW/h could suffice to achieve a maximal or near maximal myocardial glutamate uptake in most patients after CABG. The adequacy of this dosage remains to be confirmed in high-risk patients.
Place, publisher, year, edition, pages
1998. Vol. 32, no 3, 145-152 p.
adverse effects, biological transport, cardiac surgery, coronary artery disease, dose-response, human glutamate, metabolism, myocardium
National CategoryMedical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-14023DOI: 10.1080/14017439850140102OAI: oai:DiVA.org:liu-14023DiVA: diva2:22476