The locomotory behaviour of the multinucleate giant cells of foreign body reactions.
Cinemicrographic observations have shown that multinucleate giant cells are motile but the degree of translocational movement decreases with increasing size. Generally these polykaryocytes are slower than macrophages exhibiting a speed translocation of 0-3-1-0 micron/min for small polykaryocytes (2-4 nuclei) to 0-04 micron/min for large polykaryocytes (greater than 15 nuclei). Such behaviour would tend to maintain these cells near the site of their formation. The direction of translocation of small syncytia, correlates with the direction of the single leading lamellipodium. Slightly larger cells (5-15 nuclei) show loss of polarity with multiple lamellipodia, none of which is dominant, while the very large syncytia possess a single, large, circumferential lamellipodium whose movement leads to little displacement. These latter polykarya also display reduced contact inhibition which may favour fusion phenomena. Glycolysis appears to be the main source of energy for cellular movement which is also dependent on physiological calcium concentration and an intact microtubular-microfilamentous system. Apposition to the substratum is not complete, occurring in some instances by means of flaps and microvilli which may also be involved in cellular locomotion. Loss of glycocalyceal material probably occurs during locomotion.
D000818:Animals; D002459:Cell Fusion; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D003260:Contact Inhibition; D003594:Cytoplasmic Granules; D005549:Foreign-Body Reaction / Q000473:pathology*; D006097:Granulation Tissue / Q000473:pathology / Q000648:ultrastructure; D051379:Mice