Distribution of the High-Affinity Binding Site and Intracellular Target of Botulinum Toxin Type A in the Human Bladder

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

Ana Coelho (Autor) FMUP; Paulo Oliveira (Autor) FMUP; Rui Pinto (Autor) FMUP; Tiago Carvalho (Autor) FMUP; Carlos Silva (Autor) FMUP; Andre Silva (Autor) FMUP; Joao Silva (Autor) FMUP; Célia Cruz (Autor) FMUP; Francisco Cruz (Autor) FMUP; António Avelino Silva (Autor) FMUP

Revista

Título: European Urology

Vol. 57 Nº 5

Páginas: 884-890

ISSN: 0302-2838

Editora: Elsevier

Indexação

ISI Web of Knowledge - 76 Citações

Scopus - 83 Citações

Pubmed / Medline

Classificação Científica

FOS: Ciências médicas e da saúde > Medicina básica

CORDIS: Ciências da Saúde > Ciências Médicas > Medicina > Urologia

Outras Informações

ID Authenticus: P-003-6ZD

DOI: 10.1016/j.eururo.2009.12.022

Abstract (EN): Background: Botulinum toxin type A (BoNTA) has been successfully used in the treatment of refractory detrusor overactivity. The toxin is internalized after binding a high-affinity receptor, synaptic vesicle protein 2 (SV2), which is exposed in the cell membrane during the exocytosis process. In the cytoplasm, BoNTA cleaves specific sites of synaptosomal-associated protein 25 (SNAP-25), preventing the assembly of the synaptic fusion complex SNARE and blocking exocytosis. Objective: In the present work, the distribution of SV2 and SNAP-25 was first investigated in human bladders. The neurochemistry of BoNTA-sensitive structures was then investigated using markers for parasympathetic, sympathetic, and sensory fibers. Design, setting, and participants: Human bladders were obtained from cadaveric organ donors (age range: 19-74 yr). Measurements: Bladder sections were processed for single or dual immunofluorescence staining with antibodies against SV2, SNAP-25, beta-3 tubulin, vesicular acetylcholine transporter, tyrosine hydroxilase, and calcitonin gene-related peptide. Results and limitations: SV2 and SNAP-25 immunoreactive fibers were distributed throughout the suburothelium and muscular layer. Double labeling showed extensive colocalization of both proteins in nerve fibers. SV2 is more expressed in parasympathetic fibers than in sympathetic or sensory fibers. No expression was found in urothelial or muscular cells. Because only normal bladders were used, this distribution should be applied with caution to pathologic bladders. Conclusions: SV2 and SNAP-25 colocalize abundantly throughout the urinary bladder. SV2 is more abundant in cholinergic, parasympathetic fibers. These nerves are suggested to be the main target for BoNTA action in the human urinary bladder.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7