Abstract
Cytochemical analyses performed on peripheral blood smears of the Mongolian gerbil reveal the presence of variable amounts of leucocyte alkaline phosphatase (LAP) activity in the neutrophil of this species. Levels of activity in individual cells ranged from 1 to 4+. Cells completely devoid of activity were rarely encountered. Immature neutrophils residing in the bone marrow also displayed moderate amounts of enzymatic activity. The results of a semiquantitative assessment of overall LAP activity in this rodent, expressed as a mean LAP score, were compared with similar analyses carried out on a diverse sample of vertebrates. Intermediate levels of activity were recorded for the gerbil (x̄=241). This score was comparable to that obtained for the rat x̄=199) and significantly higher than that seen in man x̄=79). A wide range of LAP scores were noted for closely related species, as well as phylogenetically distant species.