Haemagglutinins and haemolysins in the body fluids of Neoamphitrite figulus and Arenicola marina (annelida : polychaeta)

Abstract

1. 1. The haemolytic and haemagglutinating activities of coelomic fluid and blood have been examined in Neoumphitrite figulus (Dalyell) and Arenicola marina (L.). 2. 2. The body fluids of some individual Arenicola marina possess weak agglutinating activity but some did not agglutinate any of the vertebrate red blood cells tested. 3. 3. While some individual variation was found, coelomic fluid showed highest titres towards rabbit red cells (RRBC) and most also agglutinated rat and guinea-pig red cells (GPRBC). 4. 4. No lysis of horse (HRBC) or chick red cells (CRBC) was found. 5. 5. The coelomic fluid of N. figulus shows both lytic and agglutinating activity towards a wider range of vertebrate red cells than A. marina. 6. 6. RRBC were the most easily lysed of those tested, but the highest agglutinin titres were obtained with HRBC. There was considerable individual variation. 7. 7. Blood showed less agglutinating activity, but all samples tested also agglutinated HRBC. 8. 8. The lysin titre of N. figulus coelomic fluid was considerably reduced by 1.0 mM EDTA when tested against sheep (SRBC) or RRBC, and was sensitive to heat (60°C, 30 min). The agglutinating activity was not Ca 2+/Mg 2+ dependent and was somewhat resistant to heat. 9. 9. There was some inhibition of activity by all sugars tested, but most noticeably by N-acetylated and methyl sugars. 10. 10. Preliminary experiments in which N. figulus were injected with SRBC or RRBC suggested some specificity of absorption of the lysin since repeated injection reduced the titre, but the agglutinin titre was not affected, nor was there any evidence of enhancement 24 hr post-injection.