Your browser doesn't support javascript.
loading
Adrenomedullin upregulates M2-muscarinic receptors in cardiomyocytes from P19 cell line.
Buys, Sophie; Smih, Fatima; Pathak, Atul; Philip-Couderc, Pierre; Verwaerde, Patrick; Montastruc, Jean-Louis; Rouet, Philippe; Senard, Jean-Michel.
Afiliación
  • Buys S; INSERM U586, Laboratoire de Pharmacologie Médicale et Clinique, Faculté de Médecine, 37 allées Jules Guesde, 31073 Toulouse Cedex, France.
Br J Pharmacol ; 139(6): 1219-27, 2003 Jul.
Article en En | MEDLINE | ID: mdl-12871842
1. The effects of AM on expression of muscarinic (M) receptors from P19-derived cardiomyocytes were examined. 2. RT-PCR experiments revealed expression of M(1)-M(4) receptor genes. Immuno-histochemistry indicated that M(2) expression is restricted to contractile cells. Carbachol inhibition of isoprenaline-induced increase in beating rate was prevented by atropine and methoctramine (pA(2): 8.1). Inhibition of [(3)H]-NMS binding by atropine (pK(i): -8.4+/-0.2) and methoctramine (pK(i): -8.3+/-0.2) suggests that M(2) is the functional expressed isoform. 3. [(3)H]-NMS binding and semiquantitative RT-PCR studies showed a dome shaped time course of M(2) expression with a maximum at 7 days of differentiation followed by a progressive decline. 4. AM concentration-dependently upregulated M(2) receptor mRNA during late differentiation stages in P19 cells but also in rat atrial cardiomyocytes. This effect was potentiated by factor H. AM (100 nM) plus factor H (50 nM) treatment of P19 cells for 24 h significantly increased [(3)H]-NMS-specific binding (B(max): 81+/-7 vs 31+/-6 fmol mg(-1) prot). The effect of AM on mRNA levels was prevented by AM receptor antagonist AM(22-52) (1 micro M) but not by CGRP antagonist, CGRP(8-37) (1 micro M). 5. The mRNA levels encoding CRLR receptor declined with culture duration, whereas those encoding L1/G10D receptor remained stable. 6. Our findings demonstrate that AM regulates M(2) receptors expression in cardiomyocytes probably through a mechanism involving L1/G10D receptors. The 'in vivo' significance of this phenomenon remains to be demonstrated.
Asunto(s)

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Péptidos / Regulación hacia Arriba / Miocitos Cardíacos / Receptor Muscarínico M2 Límite: Animals Idioma: En Revista: Br J Pharmacol Año: 2003 Tipo del documento: Article País de afiliación: Francia Pais de publicación: Reino Unido

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Péptidos / Regulación hacia Arriba / Miocitos Cardíacos / Receptor Muscarínico M2 Límite: Animals Idioma: En Revista: Br J Pharmacol Año: 2003 Tipo del documento: Article País de afiliación: Francia Pais de publicación: Reino Unido