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Secretion of coagulant factor VIII activity and antigen by in vitro cultivated rat liver sinusoidal endothelial cells
Author(s) -
Hellman Lars,
Smedsröd Bård,
Sandberg Helena,
Pettersson Ulf
Publication year - 1989
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1989.tb07751.x
Subject(s) - antiserum , cycloheximide , in vitro , secretion , immunocytochemistry , microbiology and biotechnology , biology , lysis , radioimmunoassay , antigen , cell culture , biochemistry , chemistry , endocrinology , protein biosynthesis , immunology , genetics
Summary Different types of liver cells and a few extrahepatic cell types were analysed for the presence and production of factor VIII activity (VIII: C). Only freshly prepared suspensions of rat liver sinusoidal cells and pure monolayer cultures of rat liver endothelial cells (LEC) were found to contain and secrete detectable amounts of the coagulation factor. Secretion of VIII: C by cultured LEC was inhibited by cycloheximide and by monensin. Constant levels of VIII: C were produced for at least 48 h suggesting continuous synthesis rather than a burst release of stored material. VIII: C, as measured spectro‐photometrically by conversion of X to Xa, was inhibited by anti‐human VIII: C antiserum. Indirect immunocytochemistry using this antiserum gave positive staining only with LEC. Immunoprecipitation of metabolically labelled proteins in conditioned rat LEC medium with the anti human VIII: C antiserum revealed the presence of proteins of similar sizes to those reported for human VIII:C. These results indicate that rat LEC are an important site for production and secretion of procoagulant factor VIII and are not only a site for storage and release of the factor. The established conditions for synthesis of VIII:C in in vitro cultivated rat LEC should provide the means to study the regulation of VIII:C synthesis.