Role of Endothelium in the Production of Polyblasts (Mononuclear Wandering Cells) in Inflammation by F.
Following the discovery of phagocytic cells by Ilya Ilyich Mechnikov in 1882 these cells had been called clasmatocytes, polyblasts, reticular cells, and other terms: today we designate them as macrophages or histiocytes.
The polyblasts, according to Maximow, have a double origin.
No evidence could be found in the experiments of Maximow of a participation of the endothelium of the blood vessels in the formation of polyblasts. The endothelium in inflammation forms new capillary sprouts; it may also proliferate and give off cells into the tissue which at once assume the characters of fibroblasts; but its elements never become transformed into ameboid cells.
As we were interested in the origin of the polyblasts (mononuclear exudate cells) in acute aseptic inflammation, only early stages of the process were to be cared for.
However, we repeated the experiments of Foot with the special purpose of solving the question of the origin of the mononuclear exudate cells, the polyblasts, in inflammation.
He has also pointed out that this scarcity of the emigration pictures of nongranular leukocytes, which has been looked on as one of the strong proofs against the hematogenous origin of the polyblasts, pertains equally to the special granulated leukocytes whose hematogenous origin cannot be doubted.
The hypertrophy of the emigrating lymphocytes and monocytes, which began, as we have seen, while the cells were still in the lumen, continues after their migration into the tissue; in this way the emigrated nongranulated blood leukocytes transform themselves into polyblasts (Figs.
In somewhat later stages one can follow the gradual transformation of these mobilized histiocytes into large ameboid phagocytic cells, the histogenous polyblasts (Fig.
Lymphoid, nongranulated wandering cells (with round compact, nonpolymorphous nucleus), polyblasts or mononuclear exudate cells, are now also numerous in the inflamed tissue, and their number continues to increase (Figs.