Cycloheximide as a probe of fibrinogen synthesis.
Fibrinogen synthesis in the intact rat was perturbed by treatment with cycloheximide. Specific radioactivities of fibrinogen in plasma and liver both decreased at 2 h after treatment and increased over 2-fold by 18 h. Labelled-antibody--polyribosome binding experiments showed that more polyribosomes were engaged in fibrinogen synthesis at 18 h after treatment. Radioactivity of plasma fibrinogen chains from untreated control rats showed a constant ratio of A alpha--B beta/gamma = 1.03. At 2 h after cycloheximide treatment the A alpha- and B beta-chains showed the greatest decrease in labelling (A alpha--B beta/gamma = 0.66) and at 18 h all chains were much more labelled (the A alpha--B beta/gamma ratio chainged to 1.39). The observed imbalance in fibrinogen-chain synthesis suggests that cycloheximide has a selective effect on gene expression.
D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D005340:Fibrinogen / Q000096:biosynthesis*; D007930:Leucine / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D011132:Polyribosomes / Q000378:metabolism; D051381:Rats
D005340:Fibrinogen; D003513:Cycloheximide; D007930:Leucine