Chronic treatment with otilonium bromide induces changes in L-type Ca²âº channel, tachykinins, and nitric oxide synthase expression in rat colon muscle coat.
Neurogastroenterol Motil
; 25(11): e728-39, 2013 Nov.
Article
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| MEDLINE
| ID: mdl-23901937
ABSTRACT
BACKGROUND:
Otilonium bromide (OB) is a quaternary ammonium derivative used for the treatment of intestinal hypermotility and is endowed with neurokinin2 receptor (NK2r) antagonist and Ca²âº channel blocker properties. Therefore, the possibility that OB might play a role in the neurokinin receptor/Substance-P/nitric oxide (NKr/SP/NO) circuit was investigated after chronic exposition to the drug.METHODS:
Rats were treated with OB 2-20 mg kg⻹ for 10 and 30 days. In the proximal colon, the expression and distribution of muscle NOsynthase 1 (NOS1), NK1r, NK2r, SP and Cav 1.2 subunit (for L-type Ca²âº channel) and the spontaneous activity and stimulated responses to NK1r and NK2r agonists were investigated. KEYRESULTS:
Immunohistochemistry showed a redistribution of NK1r and L-type Ca²âº channel in muscle cells with no change of NK2r at 30 days, a significant increase in muscle NOS1 expression at 10 days and a significant decrease in the SP content early in the ganglia and later in the intramuscular nerve fibers. Functional studies showed no change in spontaneous activity but a significant increase in maximal contraction induced by NK1r agonist. CONCLUSIONS & INFERENCES Chronic exposition to OB significantly affects the NKr/SP/NO circuit. The progressive decrease in SP-expression might be the consequence of the persistent presence of OB, the increase of NOS1 expression in muscle cells at 10 days in an attempt to guarantee an adequate NO production, and, at 30 days, the redistribution of the L-type Ca²âº channel and NK1r as a sign to compensate the drug channel block by re-cycling both of them. The physiological data suggest NK1r hypersensitivity.Palabras clave
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Receptores de Taquicininas
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Colon
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Óxido Nítrico Sintasa
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Canales de Calcio Tipo L
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Compuestos de Amonio Cuaternario
Idioma:
En
Revista:
Neurogastroenterol Motil
Asunto de la revista:
GASTROENTEROLOGIA
/
NEUROLOGIA
Año:
2013
Tipo del documento:
Article