Protein and amino acid metabolism in splanchnic organs in metabolic acidosis.
Metabolic acidosis causes a cooperative participation of different organs such as the liver, kidney, and muscle in restoring acid-base balance. In splanchnic organs, metabolic acidosis has repercussions on several nitrogen metabolism pathways. The decrease in urea synthesis due to reduced activity of urea cycle enzymes, ammonia uptake and amino acid transport, and changes in glutamine metabolism support renal ammoniagenesis thus offering a response to rid the body of excess protons. While some of the mechanisms are adaptive others may be harmful for the body. Metabolic acidosis may have effects on splanchnic protein turnover. In severe acidosis, synthesis of secreted liver proteins may be reduced. Acidosis may also modulate the response of the liver to growth hormone (GH) for insulin-like growth factor-I synthesis, thus inducing a state of GH resistance. Splanchnic abnormalities in acidosis might contribute to the malnutrition observed in uremia.
Deferrari
G
G
Department of Internal Medicine, University of Genoa, Italy.
Garibotto
G
G
Robaudo
C
C
Saffioti
S
S
Russo
R
R
Sofia
A
A
D000138:Acidosis / Q000378:metabolism*; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport / Q000502:physiology; D005973:Glutamine / Q000378:metabolism; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D011506:Proteins / Q000378:metabolism*; D014508:Urea / Q000378:metabolism; D014781:Viscera / Q000378:metabolism*
D000596:Amino Acids; D011506:Proteins; D005973:Glutamine; D014508:Urea; D013006:Growth Hormone