Albumin synthesis in humans increases immediately following the administration of endotoxin

Abstract

In order to investigate the immediate (i.e. within 3 h) response of albumin synthesis to the administration of endotoxin, as a model of a moderate and well controlled catabolic insult, two measurements employing L-[(2)H(5)]phenylalanine were performed in 16 volunteers. One group ( n =8) received an intravenous injection of endotoxin (4 ng/kg; lot EC-6) immediately after the first measurement of albumin synthesis, whereas the other group received saline. A second measurement was initiated 1 h later. In the endotoxin group, the fractional synthesis rate of albumin was 6.9+/-0.6%/day (mean+/-S.D.) in the first measurement. In the second measurement, a significant increase was observed (9.6+/-1.2%/day; P <0.001). The corresponding values in the control group were were 6.6+/-0.6%/day and 7.0+/-0.6%/day respectively (not significant compared with first measurement and P <0.001 compared with the second measurement in the endotoxin group). The absolute synthesis rates of albumin were 148+/-35 and 201+/-49 mg x kg(-1) x day(-1) before and after endotoxin ( P <0.01). In the control group, the corresponding values were 131+/-21 and 132+/-20 mg x kg(-1) x day(-1) (not significant compared with the first measurement and P <0.01 compared with the second measurement in the endotoxin group). In conclusion, these results indicate that albumin synthesis increases in the very early phase after a catabolic insult, as represented by the administration of endotoxin.

Simultaneous assessment of the synthesis rate and transcapillary escape rate of albumin in inflammation and surgery

“…Both volunteers [15] and cholecystitis patients [6] have been investigated previously. The temporal pattern of plasma albumin concentration in patients undergoing pancreatic resection fully reproduced a previous report [18].…”

“…Measurement of the synthesis rate of albumin employing the flooding technique with L- 2 H 5 phenylalanine has been described previously in detail [15]. Briefly, albumin in plasma samples was isolated using acid ethanol extraction, followed by extensive washing in order to remove traces of free phenylalanine and then hydrolysis with HCl.…”

Isolation of plasma albumin by ethanol extraction is inappropriate for isotope ratio measurements during the acute phase response

“…However, findings are not always consistent, and especially rates of albumin synthesis were found to vary during the acute phase response after surgical trauma. Thus, the cytokinemediated reduction of albumin synthetic capacity described in vitro [20][21][22] does not correspond to in vivo findings showing an accelerated albumin turnover [11,[23][24][25]. A portion of these discrepancies may originate from imprecise analytical methods.…”

Albumin Synthesis in States of Inflammation

“…The albumin synthesis rate was measured by the flooding dose technique comprising the incorporation of deuterium-labeled phenylalanine in de novo synthesized albumin determined by a gas chromatography mass spectrometer. [1] Total albumin pool was determined by measuring plasma volume using 125 I-albumin and plasma albumin concentrations. The 3 groups were compared by means of one-way analysis of variance.…”