TOLERANCE TO AMINO ACID MIXTURES AND CASEIN DIGESTS GIVEN INTRAVENOUSLY : GLUTAMIC ACID RESPONSIBLE FOR REACTIONS

Area of Science:

• Biochemistry
• Veterinary Medicine
• Nutritional Science

Background:

• Parenteral nutrition requires safe and effective delivery of essential nutrients.
• Amino acid mixtures are crucial for meeting daily nitrogen requirements.
• Understanding tolerance to intravenous amino acid infusions is vital for clinical application.

Purpose of the Study:

• To evaluate the tolerance of synthetic amino acid mixtures in dogs via intravenous injection.
• To identify amino acid formulations suitable for parenteral feeding.
• To investigate the impact of specific amino acids, like glutamic acid, on infusion tolerance.

Main Methods:

• Testing synthetic mixtures of essential and non-essential amino acids in canine models.
• Administering intravenous injections at varying rates (mg nitrogen/kg/min) and quantities (mg/kg).
• Observing for signs of intolerance, primarily vomiting, at different amino acid concentrations.

Main Results:

• Mixtures excluding glutamic acid were well-tolerated, even at high infusion rates (>10 mg N/kg/min).
• Inclusion of glutamic acid frequently induced vomiting, especially at rates above 4 mg N/kg/min.
• Glycine addition improved tolerance in some essential amino acid mixtures.
• Casein digests, likely due to glutamic acid, also caused vomiting at lower rates.

Conclusions:

• Synthetic amino acid mixtures free of glutamic acid are well-tolerated for intravenous administration in dogs.
• Glutamic acid appears to be a primary trigger for vomiting during parenteral feeding.
• Optimizing amino acid composition, particularly by excluding glutamic acid, can enhance the safety and utility of parenteral nutrition solutions.