[Studies on haemocytes of Oncomelania hupensis]

To establish method for collecting haemocytes of Oncomelania hupensis and study its morphology and immunological importance.

Referring to the method of haemocytes collection from peripheral lymphoid organ, suspension technique was used for collection of haemocytes from snails, which were then Giemsa-stained and observed under microscope. Stained by gentian violet, number of haemocytes was counted and compared with that of conventional squashing method and needling method by ANOVA and Dunnett-t test. Supernatant from freeze thawing haemocytes was applied for the tests of immuno-precipitation, bacteriostasis, and phagocytosis. SDS-PAGE was used to analyze relative molecular mass of protein ingredients.

Four kinds of haemocytes were found: round cells with filiform filopodia, acidophilic and basophilic round cells both without filiform filopodia, and spindle cells. The average diameter of the 4 type cells was 10.93, 6.13, 6.08, and 11:06 microm, and occupied 50%, 30%, 5%, and 15% respectively. The mean of haemocytes received from suspension, squashing and needling methods was 15 000, 6 600 and 300/ml respectively. ANOVA analysis showed F=281.47, P<0.01, and Dunnett-t test revealed t1=15.67, P<0.01 between suspension and squashing methods, and t2=24.50, P<0.01 between suspension and needling method. The supernatant of haemocytes showed precipitation with SEA, bacteriostasis with Staphylococcus aureus and Escherichia coli, and 86% phagocytosis and 46% bactericide to Candida albicans. SDS-PAGE revealed approximate Mr 112 300, 107 100, 972 00, 73 500, 600 00, 12 000 of the protein ingredients of the haemocytes.

Large amount of haemocytes has been obtained from the snails by suspension method, and the cells show immunological activities.