Recovery of macromolecular activators of phagocytosis from platelets (MAPP) producing and releasing function in stored human platelets.
Macromolecular activators of phagocytosis from platelets (MAPP) were not released from platelets prepared from platelet concentrates (PC) obtained after anticoagulation with CPD solution and stored for more than 48 h. The MAPP activity which had escaped into the plasma disappeared after 72 h of storage. After incubation in dialyzed and Ca(2+)-supplemented plasma prepared from the same PC or from fresh peripheral blood, the platelets obtained after storage for 72 h released both MAPP (l-MAPP and s-MAPP) upon thrombin stimulation. Gel filtration studies of the plasma revealed that l-MAPP and s-MAPP were produced from the platelets incubated in plasma fractions corresponding to l-MAPP and s-MAPP, respectively. These observations suggest that platelets accumulate precursors of MAPP, pre-MAPP comprising pre-l-MAPP and pre-s-MAPP, in the presence of Ca2+, and produce and release MAPP when stimulated with thrombin.
Sakamoto
H
H
Second Department of Pathology, Kagawa Medical School, Japan.
Ogawa
Y
Y
Sakamoto
N
N
Oryu
M
M
Shinnou
M
M
Hirao
T
T
D001685:Biological Factors / Q000096:biosynthesis / Q000097:blood*; D001792:Blood Platelets / Q000378:metabolism*; D006801:Humans; D018375:Neutrophil Activation; D010587:Phagocytosis
D001685:Biological Factors