Search PubMed⌕ Search

Biomedical subjects

D Lagunoff

Publications and source records attributed to D Lagunoff.

117 records · Page 7Linked to original sources

The in vitro differentiation of mast cells. Cultures of cells from immunized mouse lymph nodes and thoracic duct lymph on fibroblast monolayers.

When cells from lymph nodes or thoracic duct of mice hyperimmunized with protein antigens are cultivated on embryo monolayers in the presence of the antigen, numerous clones of mast cells appear. The histochemical and ultrastructural characteristics of the cells permit their identification as mast cells and distinguish them from the phagocytic histiocytes that usually arise in abundance in similar cultures from unimmunized mouse cells or from immunized mouse cells cultured in the absence of the antigen. Only a few colonies of mast cells appeared in the latter cultures. The basis for the induction of mast cell differentiation is not known.

Animals↗

Differentiation and proliferation of embryonic mast cells of the rat.

Histochemical reactions and radioautography were used to investigate the sequence of mast cell development in rat embryos. Mast cells arise ubiquitously in and are confined to the loose connective tissue in the embryo. The alcian blue-safranin reaction distinguishes between weakly sulfated and strongly sulfated mucopolysaccharides by a shift from alcian blue to safranin staining. Based on this reaction and morphologic characteristics, four stages were identified. Stage I mast cells are lymphocyte-like cells with cytoplasmic granules which invariably stain blue with the alcian blue-safranin reaction. In Stage II cells the majority of granules are alcian blue-positive, but some safranin-positive granules have appeared. Stage III mast cells are distinguished by a majority of safranin-positive cytoplasmic granules; some alcian blue-positive granules still remain. Stage IV cells contain only safranin-positive granules. Thymidine-H(3) uptake and identification of mitotic figures indicates that mast cells in Stages I and II comprise a mitotic pool while those in Stages III and IV are mitotically inactive. The pattern of S(35)O(4) incorporation and the sequence of appearance of histochemically identifiable mast cell constituents corroborates division of the proliferation and differentiation of embryonic mast cells into the four stages described above. The process of formation of mast cell granules is interpreted as reflecting the synthesis and accumulation of a heparin precursor in alcian blue positive granules followed by the synthesis and accumulation of highly N-sulfated heparin along with mast cell chymase and finally histamine in safranin-positive granules.

Animals↗