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. 1981 Jun 15;196(3):757–762. doi: 10.1042/bj1960757

Utilization of L-alanine and L-glutamine by lactating mammary gland of the rat. A role for L-alanine as a lipogenic precursor.

J R Viña, D H Williamson
PMCID: PMC1163095  PMID: 7317014

Abstract

1. Lactation is associated with an increase in the arterial blood concentration of L-alanine and L-glutamate, but a decrease in that of L-glutamine compared with the corresponding values for virgin rats. 2. Virgin rats fed a 'cafeteria diet' that induces hyperphagia have increased arterial concentrations of L-alanine, L-glutamate and L-glutamine. During lactation L-alanine and L-glutamate concentrations are even higher. 3. The removal of L-alanine is decreased in hepatocytes from lactating rats fed either a chow or cafeteria diet. 4. Measurements of arteriovenous differences across lactating mammary glands indicate that appreciable amounts of L-glutamine and L-alanine are extracted by the gland. 5. A high proportion of the L-alanine metabolized by isolated acini from fed lactating rats is converted into lipid. 6. Metabolism of L-alanine in acini from starved lactating rats is limited by the activity of pyruvate dehydrogenase. 7. It is concluded that L-alanine and certain other amino acids taken up by the gland in excess of the requirements for protein synthesis can be converted into lipid.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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