Antiaggregant and toxic properties of different solutions on hemocytes of three freshwater bivalves

Abstract

Hemocytes are main blood components of bivalves playing important roles in toxicological and immune responses. Consequently, a study on these cells may be useful to understand the invertebrate immunological systems. The aim of the present study was to find the best antiaggregant solution, based on its capacity of preserving the natural morphology and viability of hemocytes from the freshwater bivalves, Anodonta cygnea, Unio delphinus, and Corbicula fluminea. Hemocytes from the three species were collected and maintained in different antiaggregant solutions, i.e., ethylenediaminetetraacetic acid (EDTA), EDTA-citrate, modified Alsever solution (MAS), N-ethylmaleimide (NEM), NEM-NaCl, and heparin. The cell morphology and viability were analyzed periodically with light microscopy techniques. Between these assays with various antiaggregant solutions, the best results were obtained with NEM at a concentration of 0.05 mol·L⁻¹. It is also shown that, as expected, the osmolarity of the antiaggregant solutions plays a very important role in cell viability. Based on this study, NEM at 0.05 mol·L⁻¹ was considered an adequate antiaggregant solution for future research on immunological and toxicological responses and other physiological studies of freshwater bivalve hemocytes.

Keywords:

• Anodonta cygnea
• Anio delphinus
• Corbicula fluminea
• unionidae
• immunology

Acknowledgements

This work was supported by Fundação para a Ciência e Tecnologia (FCT) under projects PTDC/MAR/098066/2008, PTDC/AAC-AMB/117688/2010 and the PhD scholarship SFRH/BD/76265/2011. We would also like to thank António Rocha for the laboratorial expertise.