L-3,4-dihydroxyphenylalanine (L-DOPA) in Anodonta cygnea: variation with acidosis

• Tipo: Artigo em Revista Científica Internacional
• Data: 1998

Autores

Soares da Silva, IM (Autor) Outra; Almeida, MJ (Autor) Outra; Maria Paula Serrão (Autor) REIT; vieira-coelho, ma (Autor) Outra; machado, j (Autor) ICBAS

Revista

Título: Comparative biochemistry and physiology. Part A, Molecular & integrative physiology

Vol. 120

Páginas: 463-468

ISSN: 1095-6433

Editora: Elsevier

Indexação

ISI Web of Knowledge - 3 Citações

Scopus - 3 Citações

Outras Informações

ID Authenticus: P-001-7HD

DOI: 10.1016/s1095-6433(98)10046-6

Abstract (EN): L-3,4-dihydroxyphenylalanine is present in the shell, mantle cells and fluids of the bivalve Anodonta cygnea. Normal conditions, representing autumn and winter period, present high levels of L-DOPA in the fluids and low levels in the mantle. However, data show that there is a different distribution of this compound all over the mantle area, and the portions with the most significant L-DOPA content are the siphon border and the mantle part adjacent to the curvature of the shell (next to the umbo). Acidic conditions, simulating internal acidosis that occurs in Anodonta cygnea during spring and summer, show a significant variation of L-DOPA, increasing in the mantle, mainly in the central part, and decreasing in the fluids. Moreover, results indicate that L-DOPA contributes to the formation of the pellicle formed under acidosis in the nacreous layer. These variations of L-DOPA with acidosis suggest that its synthesis is increased in the central mantle and all available L-DOPA is removed from the fluids to integrate the thin pellicle formed in the nacreous layer of the shell. The recently formed periostracum and the umbo have the highest L-DOPA content in the shell because they are sclerotized structures. These results suggest that the biomineralization and sclerotization processes of the shell are closely related to the integration of L-DOPA in the nacreous layer and in the periostracum, respectively. The decrease of the internal pH appears as a relevant switch to induce the production of this amino acid in the central mantle.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6