Implication of adenosine 3',5'-cyclic monophosphate, guanosine 3',5'-cyclic monophosphate, adenosine 5'-mono-, di-, and triphosphate and fructose-2,6-bisphosphate in the regulation of the glycolytic pathway in relation to the gametogenic cycle in the mussel mytilus galloprovincialis Lmk.

The changes in the contents of cyclic AMP, cyclic GMP, ATP, ADP, AMP and fructose-2,6-bisphosphate that occur in the mantle tissue of the mussel Mytilus galloprovincialis Lmk were analysed with regard to the annual gametogenic cycle. Throughout 2 years, the lowest contents of AMP, ADP and ATP were detected during late winter-spring, whereas the maximum appeared in the autumn months. During the second year, fructose-2,6-bisphosphate and cAMP showed a very similar behaviour. The levels of both compounds rose throughout the year until a maximum in September. Their behaviour was also similar to that observed during the first year, but displaced in time. Both in 1998 and in 1999, the highest level of cGMP was detected during the spring-summer months. The results obtained suggest that the glycolytic pathway, with regard to the breeding cycle, might be regulated by fructose-2,6-bisphosphate and cyclic AMP through the activation of 6-phosphofructo-1-kinase, which is the main regulating enzyme of the glycolysis in mantle of M. galloprovincialis.