Augmented acetylcholine-induced translocation of RhoA in bronchial smooth muscle from antigen-induced airway hyperresponsive rats

1 Acetylcholine (ACh)-induced translocation of RhoA in bronchial smooth mus cle of repeatedly antigen-challenged rats that have a marked airway hyperre sponsiveness (AHR) was examined. 2 ACh induced time- and concentration-dependent translocation of RhoA. to t he plasma membrane, indicating an activation of RhoA in bronchial smooch mu scle. 3 The level of ACh-induced RhoA translocation was further increased markedl y in the AHR group as compared to that in the control group. 4 It is suggested that the augmented activation of RhoA observed in the hyp erresponsive bronchial smooth muscle might be responsible for the enhanced ACh-induced Ca2+ sensitization of bronchial smooth muscle contraction assoc iated with AHR.