Monosodium glutamate metabolism in the neonatal monkey

Am J Physiol. 1975 Jul;229(1):246-50. doi: 10.1152/ajplegacy.1975.229.1.246.

Abstract

Monosodium glutamate (MSG) administered by gastric tube to 10 infant monkeys at doses of 1-4 g/kg produced rapid increases in plasma glutamate (17- to 33-fold) and aspartate (50- to 90-fold) levels. The degree of elevation was proportional to the dose administered. Levels of other amino acids were unaffected. Two of the monkeys exhibited high fasting glutamate levels and abnormal glutamate tolerance curves. Despite this apparent decreased ability to metabolize glutamate, neither these animals nor any of the others for whom morphologic studies have been previously reported demonstrated neurotoxicity. Studies using 14-C-labeled glutamated indicated conversion of administered glutamate to two ninhydrin-negative compounds identified as glucose and lactate, as well as to asparate.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acids / blood
  • Animals
  • Aspartic Acid / blood
  • Aspartic Acid / cerebrospinal fluid
  • Aspartic Acid / metabolism
  • Blood Glucose
  • Brain / anatomy & histology
  • Dose-Response Relationship, Drug
  • Glucose / cerebrospinal fluid
  • Glucose / metabolism
  • Glutamates / blood
  • Glutamates / cerebrospinal fluid
  • Glutamates / metabolism*
  • Glutamine / blood
  • Glutamine / cerebrospinal fluid
  • Lactates / blood
  • Lactates / cerebrospinal fluid
  • Lactates / metabolism
  • Macaca / metabolism*
  • Ornithine / blood
  • Sodium Glutamate / metabolism*

Substances

  • Amino Acids
  • Blood Glucose
  • Glutamates
  • Lactates
  • Glutamine
  • Aspartic Acid
  • Ornithine
  • Glucose
  • Sodium Glutamate