The effect of crude holothurin on leucocyte phagocytosis

Differences in the ability of crude holothurin to stimulate or inhibit phagocytosis allowed an interpretation based on its effect within intracellular systems or on surface components. In concentrations of 4–100 μg per ml leucocyte suspension an increase in the phagocytosis of Staphylococcus aureus by polymorphonuclear leucocytes occurred, while Trypan blue staining showed a leucocyte mortality greater than 50 per cent in concentrations above 40 μg per ml suspension. Staphylococci treated with crude holothurin in concentrations of 500 μg per ml bacterial suspension, showed a borderline significant increase in phagocytosis. Holothurin in high concentrations (83 μg per ml WBC suspension) does not act as a serum factor but causes an alteration in the leucocyte as indicated by a significantly increased number of staphylococci phagocytosed in the presence of holothurin-treated white blood cells.