Pharmacological studies on the respiratory tract

• Published in: Japanese Journal of Pharmacology 1997, Vol.73 (suppl.2), p.250-250
• Main Authors: Yoshihiko Chiba, Toyoko Arimoto, Toshikazu Yoshikawa, Miwa Misawa
• Format: Article
• Language: Japanese
• ISSN: 0021-5198

The authors previously reported that the affinity of ACh for high-affinity agonist binding sites of bronchial muscarinic cholinoceptors was much greater in the antigen-induced airway hyperresponsive rats than in normal control ones; the affinity significantly reduced in the presence of GTPγS (Comp. Biochem. Physiol. 111C, 351-357, 1995). This observation suggests that G protein levels of the airways might increase at the airway hyperresponsiveness (AHR). In the present study, bronchial G_q protein level of the AHR rats was quantified by using Western blot analysis. The bronchial membranes of the AHR (that ware sensitized and repeatedly antigen challenged), sensitized control and normal control rats ware subjected to SDS-PAGE, and the proteins ware electrophoretically transferred to PVDF membranes. The PVDF membranes ware then incubated with antibodies against Gα_q . After further incubation with alkaline phosphatase-labeled secondary antibodies, a 42 kD band, corresponding to Gα_q , was detected. The Gα_q bands ware analyzed by computer imaging and normalized by the calculation of Gα_q /β-actin. The Gα_q protein level of the AHR rats (0.58±0.02) was significantly greater than those of the sensitized control (0.30±0.02) and normal control (0.29±0.04) rats (p