Plasma protein and liver mRNA levels of two closely related murine alpha 1-protease inhibitors during the acute phase reaction.
Plasma levels of alpha 1-PI(T) and alpha 1-PI(E), two closely related murine alpha 1-protease inhibitors, having affinities for trypsin and elastase, respectively, were compared to changes in specific liver mRNA levels after induction of the acute-phase reaction by subcutaneous injection of turpentine. In earlier, qualitative experiments an increase in plasma levels of alpha 1-PI(E), but not alpha 1-PI(T), during the acute-phase reaction had been shown. It is now shown that stimulation of plasma alpha 1-PI(E) levels reaches a maximum of 35-50% above baseline 12 h after induction of the acute-phase response using either a functional or immunological assay to measure protease inhibitor activity. Consistent with earlier observations, little or no change in plasma levels of alpha 1-PI(T) is seen. Determination of mRNA levels in the mouse liver specific for alpha 1-PI(E) and alpha 1-PI(T) was accomplished using a cell-free translation system followed by immunoprecipitation of the 35S-labeled protease inhibitors. The apparent Mr's of alpha 1-PI(E) and alpha 1-PI(T) synthesized in vitro are 42K and 46K, respectively. Apparent Mr's of the native proteins in plasma are 55K and 65K. Unexpectedly, mRNA levels for both alpha 1-PI(E) and alpha 1-PI(T) were found to increase after induction of the acute-phase reaction. Maximal stimulation for both mRNAs was approximately 300% and occurred 9 h after turpentine administration. Under these conditions, levels of translatable albumin mRNA in the mouse liver decreased to 40% of baseline in 6-9 h.
Frazer
J M
JM
Nathoo
S A
SA
Katz
J
J
Genetta
T L
TL
Finlay
T H
TH
D000209:Acute-Phase Proteins; D000818:Animals; D001798:Blood Proteins / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D007249:Inflammation / Q000097:blood*; D008099:Liver / Q000378:metabolism*; D051379:Mice; D011480:Protease Inhibitors / Q000032:analysis*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000302:isolation & purification*; D000515:alpha 1-Antitrypsin
D000209:Acute-Phase Proteins; D001798:Blood Proteins; D011480:Protease Inhibitors; D012333:RNA, Messenger; D000515:alpha 1-Antitrypsin