Enteral glutamine modulates renal glutamine utilization

Area of Science:

• Renal physiology
• Amino acid metabolism

Background:

• Glutamine plays a crucial role in renal acid-base balance and amino acid metabolism.
• Renal glutamine utilization is influenced by cellular glutamate levels and enzyme activity.

Purpose of the Study:

• To investigate the effect of enteral glutamine feeding on renal glutamine utilization.
• To elucidate the role of gamma-glutamyltransferase and cellular glutamate in regulating renal glutamine metabolism.

Main Methods:

• Rats were fed an elemental diet supplemented with glutamine.
• Gamma-glutamyltransferase was inhibited using acivicin.
• Kidney glutamate content, plasma glutamine removal, and ammonium excretion were measured.

Main Results:

• Glutamine feeding increased kidney glutamate content by 21% and reduced ammonium excretion by 27%.
• Plasma glutamine removal was significantly depressed in glutamine-fed rats.
• Acivicin administration inhibited gamma-glutamyltransferase, decreased kidney glutamate, and enhanced glutamine extraction and ammonium excretion.

Conclusions:

• Enteral glutamine feeding regulates renal glutamine utilization by increasing intracellular glutamate levels.
• Gamma-glutamyltransferase activity is a key mediator in this glutamine-glutamate-ammonium metabolic pathway within the kidney.