Different regulatory mechanisms for serum amyloid A and serum amyloid P synthesis by cultured mouse hepatocytes.
Regulation of the in vitro synthesis of the serum amyloid proteins A and P has been studied with hepatocyte cultures from CBA/J and C3H/HeJ mice. Liver cells were isolated by the collagenase perfusion technique and established for 48 h in the presence of fetal calf serum. Viable cells could then be maintained in the absence of serum for at least 72 h and in the presence of serum for up to 2 weeks. Serum amyloid A synthesis differed from serum amyloid P synthesis in three significant ways. 1) Serum amyloid A production was stimulated in the presence of fetal calf serum, whereas serum amyloid P was not; 2) serum amyloid A synthesis was increased 200% by monokine-rich macrophage supernatants while serum amyloid P was increased only 10 to 20%; 3) serum amyloid A synthesis was strikingly resistant to cycloheximide inhibition as compared with serum amyloid P and other liver proteins. It is concluded that the in vivo asynchrony of the acute phase serum amyloid A and serum amyloid P responses results at least in part from differences in regulatory mechanisms for their synthesis by hepatocytes.
D000682:Amyloid / Q000096:biosynthesis*; D000818:Animals; D002469:Cell Separation; D003513:Cycloheximide / Q000494:pharmacology; D005260:Female; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D008808:Mice, Inbred CBA; D000685:Serum Amyloid A Protein / Q000096:biosynthesis*; D000683:Serum Amyloid P-Component
D000682:Amyloid; D000685:Serum Amyloid A Protein; D000683:Serum Amyloid P-Component; D003513:Cycloheximide