tailieunhanh - Báo cáo y học: "Annual Scientific Meeting, Edmonton, September 27–30, 2007"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học General Psychiatry cung cấp cho các bạn kiến thức về ngành y đề tài: Annual Scientific Meeting, Edmonton, September 27–30, 2007. | MEETINGS ABSTRACTS Annual Scientific Meeting Edmonton September 27-30 2007 Rho Kinase Underpins Airway Smooth Muscle Hyperreactivity in Naive Caveolin-1 Knockout Mice S. Martin S. Basu D. Schaafsma . Halayko Department of Physiology Faculty of Medicine University of Manitoba and Manitoba Institute of Child Health Winnipeg MB Caveolin-1 Cav-1 can modulate intracellular signaling pathways in airway smooth muscle ASM that may mediate inflammation contraction and or proliferation. Previously we observed enhanced methacholine MCh -induced ASM contraction ex vivo and enhanced airway resistance in vivo in mice lacking Cav-1. In the present study we investigated the possible role of Rho kinase protein kinase C PKC and p42 p44 mitogen-activated protein kinase MAPK in the enhanced MCh-induced ASM contraction and airway resistance in Cav-1 knockout mice Cav-1 KO . Tracheal rings from naive 8-week-old female Cav-1 KO and genetically matched B6129SF2 J mice were isolated and mounted on a wire myograph. Isometric contraction in response to MCh was measured in the presence or absence of selective inhibitors of Rho kinase Y-27632 1 mM and 10 mM PKC bisindolylma-leimide 3 mM and p42 p44 MAPK U0126 3 mM . The role of Rho kinase in MCh-induced airway resistance Raw was also investigated in vivo using a Scireq ventilator. Thirty minutes prior to measuring respiratory mechanics Cav-1 KO and B6129SF2 J mice were exposed to aerosolized saline or Rho kinase inhibitor 5 mM Y-27632 4 minutes . Using excised tracheal rings maximum MCh-induced contraction was increased significantly in preparations from Cav-1 KO 6 mN compared to B6129SF2 J mice 6 mN . Pretreatment with 10 mM Y-27632 reduced sensitivity and maximum response to MCh in both tissues and normalized the difference in contractile responses between mouse strains. Notably whereas tracheas from Cav-1 KO exhibited concentration-dependent responses to Y-27632 maximum suppression was achieved with 1 mM of inhibitor