CGRP-LIKE MOLECULES AND CARBONIC-ANHYDRASE ACTIVITY DURING THE GROWTHOF PECTEN-MAXIMUS

In order to investigate the physiological role of calcitonin gene-rela ted peptide (CGRP) in mollusc, both circulating CGRP-related molecules and gill or mantle carbonic anhydrase activity were analysed during t he annual growth of Pecten maximus. CGRP like molecules measured by ra dioreceptor assay increased significantly during the annual cycle. Sim ilarly, gill carbonic anhydrase activity increased and showed a maximu m activity when growth is stimulated to the greatest extent. Correlati on studies showed a significant relationship between the tissue weight and either the gill carbonic anhydrase activity or the CGRP-related m olecules determined by radioreceptorassay. This observation suggests a possible interaction between carbonic anhydrase activity and CGRP. Ac cordingly, we searched for a direct effect of CGRP an the gill carboni c anhydrase activity. In gill membranes, CGRP stimulated the carbonic anhydrase activity. The maximum effect was obtained at a CGRP concentr ation of 50 nM. (C) 1998 Published by Elsevier Science Inc. All rights reserved.