Differential sodium fluoride sensitivity of alpha-naphthyl acetate esterase in human, bovine, canine, and murine monocytes and lymphocytes.

The sensitivity of alpha-naphthyl acetate esterase (ANAE) activity of human, bovine, canine, and murine leukocytes to low (42 micrograms/ml incubation mixture) and high (1.5 mg/ml incubation mixture) concentrations of sodium fluoride (NaF) was compared. The ANAE activity of bovine and canine monocytes was only slightly inhibited by the low concentration of NaF, whereas that of murine peritoneal macrophages was moderately inhibited and that of human monocytes was completely inhibited. Human and canine monocytic ANAE was completely inhibited by the high concentration of NaF, whereas the ANAE activity in 1% of bovine monocytes and murine peritoneal macrophages was not inhibited. The ANAE activity of human and murine lymphocytes in nonenriched venous blood samples showed no or negligible NaF sensitivity to the low concentration of NaF, whereas bovine lymphocytic ANAE showed slight and canine lymphocytic ANAE moderate NaF sensitivity. The ANAE of murine T-lymphoma L5178Y cells was resistant to the low concentration of NaF, but the ANAE of both murine T-lymphoma L5178Y cells and murine lymphocytes was completely inhibited by the high concentration of NaF. Human, bovine, and canine lymphocytic ANAE showed marked NaF sensitivity toward the high concentration of NaF, showing 73%, 86%, and 93% inhibition, respectively. The neutrophils in murine venous blood and ascites were positive for ANAE activity, which was only slightly inhibited by the low concentration of NaF but completely inhibited by the high concentration. Results of this investigation demonstrate that the ANAE of leukocytes of various species show remarkable differences in its sensitivity to low and high concentrations of NaF, indicating that appropriate concentrations of NaF are required for distinguishing the ANAE of lymphocytes and monocytes of different species.