This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Toporek, M. Search for Related Content PubMed PubMed Citation Articles by Toporek, M.

Effect of Perfusing Blood on Serum Protein Production by Isolated Perfused Livers from Normal or Tumor-bearing Rats¹

Department of Biochemistry, Jefferson Medical College, Philadelphia, Pennsylvania 19107

Isolated perfused rat liver experiments were performed in which normal livers and livers from Walker 256 tumor-bearing rats were perfused with normal blood or blood from tumor-bearing rats. The serum protein synthetic activity of the perfused livers was determined by following the incorporation of L-lysine-6-¹⁴C into total serum protein and the albumin and - and ß-globulin fractions of the perfusing blood. Radioactivity of the protein samples was determined by combustion to CO₂, absorption in an ethanolamine-ethylene glycol monomethyl ether solution, followed by liquid scintillation counting.

Results indicate that blood from tumor-bearing rats carries an inhibitory signal which causes a decrease in the serum protein synthetic activity of the perfused liver. Thus normal livers perfused with blood from tumor-bearing rats have a lower serum protein synthetic activity than normal livers perfused with normal blood. In the same way, livers from tumor-bearing rats perfused with blood from tumor-bearing rats have a lower serum protein synthetic activity than livers from tumor-bearing rats perfused with normal blood. Also, livers from tumor-bearing rats perfused with normal blood were found to have a higher serum protein synthetic activity than livers from normal rats perfused with normal blood.

¹ This work was supported in part by USPHS Grant CA-04236-08 from the National Cancer Institute and National Science Foundation Grant GB-6504 from the Physiological Processes Section.

Received 10/ 7/68. Accepted 1/21/69.