The ultrastructure of platelet pseudopodia and the adhesion of homologous platelets to tumour cells.

  • 1 December 1970
    • journal article
    • Vol. 51  (6) , 570-80
Abstract
When homologous platelets in plasma were mixed in a Chandler tube apparatus with Walker 256 carcinoma cells and mouse mammary adenocarcinoma cells a tumour-platelet body was formed in each case. Walker 256 carcinoma cells and rat platelets formed a loosely knit corpus of tumour cells, tumour cell debris, and activated platelets which showed a number of pseudopodia in contact with both intact and damaged tumour cells. Mouse mammary adenocarcinoma cells and mouse platelets formed a denser corpus consisting of platelets with numerous pseudopodia, fibrin and tumour cells. Mixed in this mass were “balloon” platelets. These were pear-shaped profiles of single platelets in which the larger spheroid was granule-free and the smaller granule-rich. No granules were seen external to the platelet plasma membrane. Platelet pseudopodia took various forms. Single filiform, bifid and staghorn types were seen. Some originated from the microtubular system and were supported by it. A peripheral bubble containing membranes arranged in a foamy fashion was present at the tip of some pseudopodia. If the leading portion of a pseudopodium had reached an attractive adhesive surface then it followed this surface for a little distance so as to result in a bend away from the main axis of the pseudopodium.