Abstract
In view of conflicting evidence for a major hepatic role in the synthesis of circulating plasminogen, the precursor of the fibrinolytic enzyme plasmin, we carried out the present study with a sensitive assay in order to measure the accumulation of small quantities of plasminogen in a recycling rat liver perfusion system. We have purified plasminogen from Sprague-Dawley rat plasma and have raised a monospecific antiserum against it in rabbits. Isolated rat liver perfusions were performed with an oxygenated recycling perfusate consisting of a perfluorotributylamine/Pluronic F-68 emulsion (Fluosol 43) free of plasma proteins and blood cells. The system was shown to be capable of synthesizing albumin and transferrin. The cumulative appearance of plasminogen in the perfusate was measured by a sensitive, specific radioimmunoassay. Plasminogen concentration increased progressively during the first 2 hr of perfusion; the observed average net synthesis in five separate experiments was approximately 35 microgram/hr per 100 g of body weight. Exposure of the perfused liver to 18 microM cycloheximide inhibited additional increase in the titer of plasminogen. Evidence for de novo synthesis was provided by the incorporation of 14C-labeled leucine into specific immunoprecipitates of plasminogen and the inhibition of this incorporation by cycloheximide. Analysis of the immunoprecipitates by sodium dodecyl sulfate/polyacrylamide gel electrophoresis revealed a single peak of radioactivity corresponding to Mr of 82,000. These data indicate that the liver is a major site of plasminogen production.
Full text
PDF



Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Algranati I. D., Sabatini D. D. Effect of protease inhibitors on albumin secretion in hepatoma cells. Biochem Biophys Res Commun. 1979 Sep 12;90(1):220–226. doi: 10.1016/0006-291x(79)91613-9. [DOI] [PubMed] [Google Scholar]
- Anker H. S. A solubilizable acrylamide gel for electrophoresis. FEBS Lett. 1970 Apr 16;7(3):293–293. doi: 10.1016/0014-5793(70)80185-5. [DOI] [PubMed] [Google Scholar]
- BARNHART M. I., RIDDLE J. M. Cellular localization of profibrinolysin (plasminogen). Blood. 1963 Mar;21:306–321. [PubMed] [Google Scholar]
- Bohmfalk J. F., Fuller G. M. Plaminogen is synthesized by primary cultures of rat hepatocytes. Science. 1980 Jul 18;209(4454):408–410. doi: 10.1126/science.7384814. [DOI] [PubMed] [Google Scholar]
- Cooksley W. G., ENGLAND J. M., Louis L., Down M. C., Tavill A. S. Hepatic vitamin B12 release and transcobalamin II synthesis in the rat. Clin Sci Mol Med. 1974 Dec;47(6):531–545. doi: 10.1042/cs0470531. [DOI] [PubMed] [Google Scholar]
- Deutsch D. G., Mertz E. T. Plasminogen: purification from human plasma by affinity chromatography. Science. 1970 Dec 4;170(3962):1095–1096. doi: 10.1126/science.170.3962.1095. [DOI] [PubMed] [Google Scholar]
- Highsmith R. F., Kline D. L. Plasminogen restoration by the kidney mediated by a plasma factor. Am J Physiol. 1973 Nov;225(5):1032–1037. doi: 10.1152/ajplegacy.1973.225.5.1032. [DOI] [PubMed] [Google Scholar]
- MATTII R., AMBRUS J. L., SOKAL J. E., MINK I. PRODUCTION OF MEMBERS OF THE BLOOD COAGULATION AND FIBRINOLYSIN SYSTEMS BY THE ISOLATED PERFUSED LIVER. Proc Soc Exp Biol Med. 1964 May;116:69–72. doi: 10.3181/00379727-116-29161. [DOI] [PubMed] [Google Scholar]
- Mattler L. E., Bang N. U. Serine protease specificity for peptide chromogenic substrates. Thromb Haemost. 1977 Dec 15;38(4):776–792. [PubMed] [Google Scholar]
- Morton A. G., Tavill A. S. The role of iron in the regulation of hepatic transferrin synthesis. Br J Haematol. 1977 Jul;36(3):383–394. doi: 10.1111/j.1365-2141.1977.tb00662.x. [DOI] [PubMed] [Google Scholar]
- Nováková V., Birke G., Plantin L. O., Wretlind A. A perfluorochemical oxygen carrier (fluosol-43) in a synthetic medium used for perfusion of isolated rat liver. Acta Physiol Scand. 1976 Nov;98(3):356–365. doi: 10.1111/j.1748-1716.1976.tb10320.x. [DOI] [PubMed] [Google Scholar]
- PURCELL G., Jr, PHILLIPS L. L. FIBRINOLYTIC ACTIVITY IN CIRRHOSIS OF THE LIVER. Surg Gynecol Obstet. 1963 Aug;117:139–144. [PubMed] [Google Scholar]
- REMMERT L. F., COHEN P. P. Partial purification and properties of a proteolytic enzyme of human serum. J Biol Chem. 1949 Nov;181(1):431–448. [PubMed] [Google Scholar]
- Raum D., Marcus D., Alper C. A., Levey R., Taylor P. D., Starzl T. E. Synthesis of human plasminogen by the liver. Science. 1980 May 30;208(4447):1036–1037. doi: 10.1126/science.6990488. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robbins K. C. The human plasma fibrinolytic system: regulation and control. Mol Cell Biochem. 1978 Aug 16;20(3):149–157. doi: 10.1007/BF00243761. [DOI] [PubMed] [Google Scholar]
- Saito H., Goldsmith G. H., Jr Plasma thromboplastin antecedent (PTA, factor XI): a specific and sensitive radioimmunoassay. Blood. 1977 Sep;50(3):377–385. [PubMed] [Google Scholar]
- Siefring G. E., Jr, Castellino F. J. De novo biosynthesis of plasminogen in the anephric rat. J Appl Physiol. 1975 Jan;38(1):114–116. doi: 10.1152/jappl.1975.38.1.114. [DOI] [PubMed] [Google Scholar]
- Siefring G. E., Jr, Castellino F. J. Metabolic turnover studies on the two major forms of rat and rabbit plasminogen. J Biol Chem. 1974 Mar 10;249(5):1434–1438. [PubMed] [Google Scholar]
- Steinbuch M., Audran R. The isolation of IgG from mammalian sera with the aid of caprylic acid. Arch Biochem Biophys. 1969 Nov;134(2):279–284. doi: 10.1016/0003-9861(69)90285-9. [DOI] [PubMed] [Google Scholar]
- Weber K., Osborn M. The reliability of molecular weight determinations by dodecyl sulfate-polyacrylamide gel electrophoresis. J Biol Chem. 1969 Aug 25;244(16):4406–4412. [PubMed] [Google Scholar]
