Schistosomiasis differentially affects vasoconstrictor responses: up-regulation of 5-HT receptor-mediated aorta contraction

• Autor(a) principal: Oliveira,Suellen D'Arc dos Santos
• Data de Publicação: 2011
• Outros Autores: Silva,Claudia Lucia Martins
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Memórias do Instituto Oswaldo Cruz
• Texto Completo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762011000400012
• topic: vascular; schistosomiasis; nitric oxide; Rho kinase; 5-HT; immune-vascular

Schistosomiasis, classified by the World Health Organization as a neglected tropical disease, is an intravascular parasitic disease associated to a chronic inflammatory state. Evidence implicating inflammation in vascular dysfunction continues to mount, which, broadly defined, reflects a failure in the control of intracellular Ca2+ and consequently, vascular contraction. Therefore, we measured aorta contraction induced by 5-hydroxytryptamine (5-HT) and endothelin-1 (ET-1), two important regulators of vascular contraction. Isometric aortic contractions were determined in control and Schistosoma mansoni-infected mice. In the infected animals, 5-HT induced a 50% higher contraction in relation to controls and we also observed an increased contraction in response to Ca2+ mobilisation from sarcoplasmic reticulum. Nevertheless, Rho kinase inhibition reduced the contraction in response to 5-HT equally in both groups, discarding an increase of the contractile machinery sensitivity to Ca2+. Furthermore, no alteration was observed for contractions induced by ET-1 in both groups. Our data suggest that an immune-vascular interaction occurs in schistosomiasis, altering vascular contraction outside the mesenteric portal system. More importantly, it affects distinct intracellular signalling involved in aorta contraction, in this case increasing 5-HT receptor signalling.