Synthesis rate of plasma albumin is a good indicator of liver albumin synthesis in sepsis

Plasma albumin is well known to decrease in response to inflammation. The r ate of albumin synthesis from both liver and plasma was measured in vivo by use of a large dose of L-[H-2(3)-C-14] valine in rats injected intravenous ly with live Escherichia coli and in pair-fed control rats during the acute -phase period (2 days postinfection). The plasma albumin concentration was reduced by 50% in infected rats compared with pair-fed animals. Infection i nduced a fall in both liver albumin mRNA levels and albumin synthesis relat ive to total liver protein synthesis. However, absolute liver albumin synth esis rate (ASR) was not affected by infection. In plasma, albumin fractiona l synthesis rate was increased by 50% in infected animals compared with pai r-fed animals. The albumin ASR estimated in the plasma was similar in the t wo groups. These results suggest that hypoalbuminemia is not due to reduced albumin synthesis during sepsis. Moreover, liver and plasma albumin ASR we re similar. Therefore, albumin synthesis measured in the plasma is a good i ndicator of liver albumin synthesis.