Ethionine-dependent inhibition of acute-phase plasma protein synthesis in the rat.

Ethionine administered intraperitoneally to rats suffering from turpentine-induced inflammation preferentially reduced incorporation of 14C-leucine into fibrinogen, haptoglobin and other acute-phase proteins. The inhibitory effect was observed both in vivo and in liver slices obtained from ethionine-treated donors, while addition of ethionine to liver slices in vitro led to general reduction of synthesis of all liver and plasma proteins, including albumin. For comparison, the effects of galactosamine and actinomycin D on plasma protein synthesis in injured rats were also examined. It has been concluded that ethionine acts in the early phases of the acute-phase response, probably by inhibition of trauma-induced transcription of liver mRNA specific for acute-phase proteins.