L-asparaginase: acute effects on protein synthesis in rabbits with normal
and increased fibrinogen production
BM Alving, CF Barr and DB Tang
The acute effects of a single intravenous dose of L-asparaginase on protein
synthesis were studied in normal rabbits and in animals that had received
turpentine to stimulate fibrinogen production. Male New Zealand rabbits
received L-asparaginase (500 U/kg) 16 hr before the injection of the
radiolabeled amino acid [75Se]selenomethionine (75SeM). Incorporation of
75SeM into fibrinogen and serum proteins in the L-asparaginase-treated
rabbits was the same as for saline-treated controls, with fibrinogen
representing approximately 5% of the labeled plasma proteins. In
turpentine-treated rabbits, the maximal incorporation of 75SeM into serum
proteins remained unchanged, whereas 75SeM-fibrinogen increased sixfold and
accounted for 25% of the labeled proteins. Animals that received
L-asparaginase at the same time as turpentine or 14 hr later showed
significant decreases in synthesis of both serum proteins and fibrinogen.
75SeM-fibrinogen that was purified from L-asparaginase-treated rabbits
underwent normal catabolism when injected into normal recipient rabbits.
These data indicate that L- asparaginase can acutely cause partial
inhibition of both serum protein and fibrinogen synthesis when administered
to rabbits shortly before or during a period of increased fibrinogen
production. Fibrinogen that is synthesized in the presence of
L-asparaginase does not have an abnormal rate of catabolism.
Volume 63,
Issue 4,
pp. 823-827,
04/01/1984
Copyright © 1984 by The American Society of Hematology
