liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Metabolic and hemodynamic effects of intravenous glutamate infusion early after coronary operations
Linköping University, Department of Medicine and Care, Thoracic Surgery. Linköping University, Faculty of Health Sciences.
Linköping University, Department of Medicine and Care, Thoracic Surgery. Linköping University, Faculty of Health Sciences.
Linköping University, Department of Medicine and Care, Thoracic Surgery. Linköping University, Faculty of Health Sciences.
Department of Anesthesiology, Akademiska Hospital, Uppsala, Sweden.
Show others and affiliations
1996 (English)In: Journal of Thoracic and Cardiovascular Surgery, ISSN 0022-5223, E-ISSN 1097-685X, Vol. 112, no 6, 1468-1477 p.Article in journal (Refereed) Published
Abstract [en]

Amino acids, particularly glutamate, have been proposed to play an important role in the recovery of cardiac oxidative metabolism after ischemia. In this investigation, the metabolic and hemodynamic effects of glutamate infusion after coronary operations were studied. From 220 to 240 ml 0.1 mol/L l-glutamic acid solution was infused in 10 patients during 1 hour starting 2 hours after operation. A control group of 10 patients received an infusion of 240 ml saline solution. During glutamate infusion, there were significant increases in the uptake of glutamate (from 0.7 ± 0.2 μmol/min in the basal state to a peak of 5.7 ± 1.2 μmol/min at 20 minutes) and lactate (from 4.9 ± 2.0 μmol/min in the basal state to 14.1 ± 4.4 μmol/min at 60 minutes; p < 0.01), whereas the uptake and release of other substrates remained essentially unaffected. Arterial glutamate levels (in whole blood) increased from 103 ± 10 μmol/L to 394 ± 20 μmol/L at 60 minutes. Thirty minutes after discontinuation of the glutamate infusion, arterial levels had decreased to 129 ± 17 μmol/L. The markedly improved utilization of lactate and the unchanged release of alanine together suggest that the oxidative metabolism of the heart was stimulated by glutamate. The metabolic changes were associated with improved myocardial performance. Left ventricular stroke work index increased from 26.8 ± 2.1 gm · beat-1· m-2body surface area to 31.3 ± 3.1 gm · beat-1· m-2body surface area during glutamate infusion. Metabolic support with amino acids may provide a means to improve recovery of metabolic and hemodynamic function of the heart early after cardiac operations.

Place, publisher, year, edition, pages
1996. Vol. 112, no 6, 1468-1477 p.
National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:liu:diva-79552DOI: 10.1016/S0022-5223(96)70005-3OAI: oai:DiVA.org:liu-79552DiVA: diva2:543468
Available from: 2012-08-08 Created: 2012-08-08 Last updated: 2017-12-07Bibliographically approved
In thesis
1. Metabolic intervention with amino acids in coronary surgery: A clinical study with special reference to effects of glutamate and aspartate on myocardial metabolism
Open this publication in new window or tab >>Metabolic intervention with amino acids in coronary surgery: A clinical study with special reference to effects of glutamate and aspartate on myocardial metabolism
2000 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Amino acids, particularly glutamate and aspartate, have been suggested to be important for the tolerance to myocardial ischemia and for the recovery of the oxidative metabolism of the heart after ischemia. The objective of the present work was to investigate myocardial metabolism and how it is influenced by intravenous supply of glutamate and aspartate in association with coronary artery bypass grafting (CABG). Three groups, comprising a total of 49 patients, were studied with classical organ balance technique. 30 patients with stable angina were studied 1-2 hour after CABG and 19 patients with unstable angina were studied before cardiopulmonary bypass (CPB) and during early reperfusion.

Glutamate infusion early after elective CABG caused a dose-dependent linear increase in arterial levels and increased myocardial uptake of glutamate. The greatest impact on myocardial glutamate uptake was achieved by increasing arterial whole blood level by less than 100 μmol/L, while a further increase of arterial level was associated with marginal effects on myocardial uptake. The fractional uptake of lactate increased during glutamate infusion, whereas myocardial exchange of other substrates remained essentially unaffected. These metabolic changes were associated with improved myocardial performance.

Aspartate infusion in the same setting resulted in a dose-dependent linear increase of both arterial aspartate level and myocardial uptake of aspartate. No positive effects on myocardial metabolism or function were demonstrated. However, considerable interactions with glutamate metabolism, compatible with competitive inhibition of myocardial glutamate uptake were observed.

In patients with unstable angina the only substrate extracted by the heart immediately before CPB was free fatty acids (FFAs). In contrast, during glutamate infusion a significant myocardial uptake of glutamate and lactate was also found. The uptake of lactate correlated with arterial levels of lactate (r0.83; p<0.01). Myocardial metabolism during early reperfusion was characterized by dynamic changes including low oxygen extraction, lactate release, a shift towards increased glucose utilization. At the end of the study period oxygen extraction had normalized but in the control group there was still no uptake of lactate. Glutamate infusion resulted in myocardial uptake of glutamate and a significant myocardial uptake of lactate was found at the end of the study period (15 minutes after weaning from CPB). A substantial uptake ofFFAs was observed in both groups.

In conclusion, this study demonstrates beneficial metabolic effects of myocardial glutamate augmentation in association with CABG. The normal lactate metabolism in patients with unstable angina before revascularization suggests enhanced myocardial tolerance to ischemia and the improved lactate metabolism during early reperfusion and after completion of surgery is compatible with improved recovery of the oxidative metabolism.

Place, publisher, year, edition, pages
Linköping: Linköpings universitet, 2000. 64 p.
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 631
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-27551 (URN)12212 (Local ID)91-7219-588-6 (ISBN)12212 (Archive number)12212 (OAI)
Public defence
2000-05-26, Berzeliussalen, Universitetssjukhuset, Linköping, 09:00 (Swedish)
Opponent
Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2012-08-08Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Authority records BETA

Svedjeholm, RolfVanhanen, IngemarHåkansson, ErikNilsson, Lennart

Search in DiVA

By author/editor
Svedjeholm, RolfVanhanen, IngemarHåkansson, ErikNilsson, Lennart
By organisation
Thoracic SurgeryFaculty of Health SciencesClinical Chemistry
In the same journal
Journal of Thoracic and Cardiovascular Surgery
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 128 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf