Effect of chronic, extrinsic denervation on functional NANC innervation with vasoactive intestinal polypeptide and substance P in longitudinal muscle of rat jejunum.
Neurogastroenterol Motil
; 20(3): 243-52, 2008 Mar.
Article
em En
| MEDLINE
| ID: mdl-17971029
ABSTRACT
Intestinal denervation contributes to enteric motor dysfunction after intestinal transplantation [small bowel transplantation (SBT)]. Our aim was to determine long-term effects of extrinsic denervation on functional non-adrenergic, non-cholinergic innervation with vasoactive intestinal polypeptide (VIP) and substance P. Contractile activity of jejunal longitudinal muscle from six age-matched, naïve control rats (NC) and eight rats 1 year after syngeneic SBT were studied in tissue chambers. Spontaneous contractile activity did not differ between groups. Exogenous VIP inhibited contractile activity dose-dependently in both groups, greater in NC than in SBT. The VIP antagonist ([D-p-Cl-Phe(6),Leu(17)]-VIP) and the nitric oxide synthase inhibitor l-N(G)-nitro arginine prevented inhibition by exogenous VIP and electrical field stimulation (EFS) in both groups. Exogenous substance P increased contractile activity dose-dependently, greater in NC than in SBT. The substance P antagonist ([D-Pro(2),D-Trp(7,9)]-substance P) inhibited effects of exogenous substance P and increased the EFS-induced inhibitory response. Immunohistofluorescence showed staining for tyrosine hydroxylase in the jejunoileum 1 year after SBT suggesting sympathetic reinnervation. In rat jejunal longitudinal muscle after chronic denervation, response to exogenous VIP and substance P is decreased, while endogenous release of both neurotransmitters is preserved. These alterations in excitatory and inhibitory pathways occur despite extrinsic reinnervation and might contribute to enteric motor dysfunction after SBT.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Peptídeo Intestinal Vasoativo
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Substância P
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Sistema Nervoso Entérico
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Jejuno
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Músculo Liso
Limite:
Animals
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article