INDUCTION OF LYSOZYME-LIKE ACTIVITY IN THE HEMOLYMPH AND HEMOCYTES OF AN INSECT, SPODOPTERA-ERIDANIA

Lysozymelike activity is present in the hemocytes and cell-free hemolymph of Spodoptera eridania. Its level remains essentially constant during larval development and can be induced by injection of various foreign materials. Serum bacteriolytic activity rises 24 hr after injection of saline, BSA, bacteria, bacterial endotoxin (LPS), latex particles, or sham injection. However, the magnitude and subsequent duration of the response depends on the nature of the injected material. The response is transient following sham injection or injection of soluble substances, such as saline and BSA, as compared to treatment with latex or bacteria. Both soluble and insoluble fractions of bacterial LPS preparations stimulated the lysozyme response. The response to a single injection of E. coli LPS was dose dependent and persisted for at least 5 days; however, additional injections had no effect on serum lysozyme level. The basal intracellular lysozyme level was significantly increased by E. coli LPS injection. Lysozyme release by hemocytes was proportional to intracellular concentration and did not increase after phagocytic stimulation of hemocytes. © 1979.