Resident human peritoneal macrophages: a monocytic cell line.

Experiments were devised to clarify the cellular origin of human peritoneal macrophages. As a cell marker, the specific isoenzyme pattern of acid esterase was studied in separated normal blood cells and resident (sessile) peritoneal macrophages using isoelectric focusing. The enzyme pattern of peritoneal macrophages differed from that of all blood cells with the exception of blood monocytes. They showed all five specific monocytic isoenzymes in addition to two further bands. The results show that resident peritoneal macrophages, like exudate peritoneal macrophages, are derived from blood monocytes.