Cytochemical study of phosphatases in globule leucocytes isolated from rat tracheal epithelium

In this cytochemical study, the presence of acid phosphatase and alkaline phosphatase was investigated in globule leucocytes isolated from rat tracheal epithelium. The isolation and enrichment procedure used yields a cell fraction of apparently undamaged globule leucocytes, exhibiting a cell viability of at least 96%, as assessed by trypan blue exclusion, and surviving at least in short-term culture. The cytochemical methods applied demonstrate that isolated tracheal globule leucocytes are positive for acid phosphatase activity, but negative for alkaline phosphatase activity. The acid phosphatase activity is fluoride-sensitive, as it is completely inhibited in the presence of 10 mM NaF. Isolated rat peritoneal cells were used as positive control cells for the cytochemical reactions. The possible significance of acid phosphatase in globule leucocytes is discussed in connection with the previously suggested cell functions.