Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài:"Airway smooth muscle relaxation results from a reduction in the frequency of Ca2+ oscillations induced by a . | Respiratory Research BioMed Central Research Open Access Airway smooth muscle relaxation results from a reduction in the frequency of Ca2 oscillations induced by a cAMP-mediated inhibition of the IP3 receptor Yan Bai and Michael J Sanderson Address Department of Physiology University of Massachusetts Medical School 55 Lake Avenue North Worcester MA 01655 USA Email Yan Bai - Michael J Sanderson - Corresponding author Published 23 February 2006 Received 05 December 2005 Respiratory Research2006 7 34 doi 1465-9921 -7-34 Accepted 23 February 2006 This article is available from http content 7 1 34 2006Bai and Sanderson licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background It has been shown that the contractile state of airway smooth muscle cells SMCs in response to agonists is determined by the frequency of Ca2 oscillations occurring within the SMCs. Therefore we hypothesized that the relaxation of airway SMCs induced by agents that increase cAMP results from the down-regulation or slowing of the frequency of the Ca2 oscillations. Methods The effects of isoproterenol ISO forskolin FSK and 8-bromo-cAMP on the relaxation and Ca2 signaling of airway SMCs contracted with methacholine MCh was investigated in murine lung slices with phase-contrast and laser scanning microscopy. Results All three cAMP-elevating agents simultaneously induced a reduction in the frequency of Ca2 oscillations within the SMCs and the relaxation of contracted airways. The decrease in the Ca2 oscillation frequency correlated with the extent of airway relaxation and was concentrationdependent. The mechanism by which cAMP reduced the frequency of the Ca2 .
