B16005: Sixteen in vitro neurotransmitter receptor competitive binding studies on cockle extracts
Wednesday 13 October 2004
This in vitro research project aimed to investigate the nature of the toxic effects of atypical cockle extracts by examining the possibility that the extract may affect cell receptors of the mammalian nervous system.
Background
Since June 2001, atypical responses have been observed during the Diarrhetic Shellfish Poisoning (DSP) assay used within the UK statutory biotoxin monitoring programme. These have occurred primarily from cockles from England, Wales and Northern Ireland, but also from small numbers of mussels from England and Wales. This project examined the potential binding of substances in cockle extracts that give rise to the atypical response in the mouse bioassay (MBA) to a wide-range of receptors in the central and peripheral nervous systems of rodents.
Research Approach
This project aimed to elucidate the possible neurotoxic effects of atypical cockle extracts. To this end, in vitro competitive binding studies were carried out, which measured the ability of substances found in cockle extracts to bind to 16 different types of neurotransmitter receptors of the central and peripheral nervous system. For each receptor type the binding ability of atypical cockle extract was, firstly, compared with the binding ability of cockle extract that provoked no atypical response and, secondly, with the binding ability of a blank that contained no cockle extract.
The study was set up to provide information to complement the data obtained in a parallel neurotoxicity study (B16004).
Results and findings
This in vitro research project examined the ability of substances in atypical cockle extract to bind to 16 different physiologically important mammalian neurotransmitter receptors to help determine the putative neurotoxic mechanism of action of the agent responsible for the atypical responses in the diarrhetic shellfish poisoning (DSP) assay.
For one of the 16 neurotransmitter receptors assayed, the study found a significantly increased ability of the atypical cockle extract to bind to the receptor compared to a negative cockle extract. An interaction at this receptor by a soluble component of the atypical cockle extract may play a role in the mechanism of action associated with the mouse bioassay (MBA) atypical response induced by the positive cockle extract. The results of this study will inform future research by the FSA into the cause and nature of the atypical DSP MBA response.
Dissemination information
The final report is available from the FSA Library and Information centre.
To obtain a copy, please contact the Enquiry Desk, Dr Elsie Widdowson Library and Information Services, Food Standards Agency (tel: 020 7276 8181/8182 or email: library&info@foodstandards.gsi.gov.uk)
Contact: For any enquiries concerning this research project, please contact the relevant Programme contact or email science@foodstandards.gsi.gov.uk