title: Contractile effect of tachykinins on rabbit small intestine.
abstract: OBJECTIVE
  To study the role of the tachykinin receptors in spontaneous contractions of longitudinal and circular smooth muscle from rabbit small intestine and to determine the mechanism of action of Substance P (SP).
  
  
  METHODS
  Rabbit duodenum, jejunum and ileum segments were prepared. The spontaneous contractions of longitudinal and circular smooth muscle were recorded using a computer via an isometric force transducer. The specific agonists and antagonists of tachykinin receptors were added into the organ bath.
  
  
  RESULTS
  The agonists of tachykinin NK1 receptor (SP and [Sar9] SP), NK2 receptor (NKA and (β-Ala8)-NKA), and NK3 receptor (NKB and Senktide) all induced contractions in the small intestine. The contractions were diminished by NK1 receptor antagonist L-733,060, NK2 receptor antagonist GR-94800, and NK3 receptor antagonist SB 218795. Contractions caused by SP were also reduced by atropine, verapamil, PKC inhibitor staurosporine, and PLC inhibitor U73122.
  
  
  CONCLUSIONS
  Ttachykinin NK1, NK2, and NK3 receptors mediate the contractions of the smooth muscle in rabbit intestine. Furthermore, SP acts directly on smooth muscle cells through the tachykinin NK1 receptor.
authors: Departamento de Farmacología y Fisiología (Fisiología), Facultad de Veterinaria, Universidad de Zaragoza, Miguel Servet 177, Zaragoza, Spain.
authors: Marta Sofía
authors: MS
authors: Valero
authors: Diego Santos
authors: DS
authors: Fagundes
authors: Laura
authors: L
authors: Grasa
authors: María Pilar
authors: MP
authors: Arruebo
authors: Miguel Ángel
authors: MÁ
authors: Plaza
authors: María Divina
authors: MD
authors: Murillo
mesh_terms: D000818:Animals; D007421:Intestine, Small / Q000187:drug effects* / Q000502:physiology; D008297:Male; D011817:Rabbits; D015320:Tachykinins / Q000494:pharmacology*
chemical_list: D015320:Tachykinins