Studies on epithelial phagocytosis.-I

Abstract

In experiments on 40 rabbits, suspensions of Hydrokollag (a proprietary colloidal suspension of graphite), carmine, cocoa butter, and live and dead Staphylococcus aureus and tubercle bacilli, were aseptically introduced by injection either into the vagina or into the upper end of 1 uterine horn exposed by median laparotomy. Hydrokollag, carmine, and bacteria were phagocytosed by non-ciliated columnar cells of the vaginal epithelium; cocoa butter and olive oil were absorbed by, and appeared as fatty globules in, non-ciliated columnar cells of vagina and uterus, but this is regarded as absorption rather than phagocytosis. These columnar cells have, distally, blunt projections resembling pseu-dopodia; they possess a layer of mucin and are presumably sticky and able to hold foreign bodies. The need for stringent criteria in defining phagocytosis is stressed, and the criteria employed are described. They are: (i) ability to bring into the same focal plane some portion of the nucleus and the suspected ingested material; (ii) to identify the cell-membrane as being definitely outside the particles. The presence of cytoplasmic vacuoles around ingested particles such as carmine and staphylo-cocci is additional evidence of phagocytosis.