tailieunhanh - Báo cáo y học: "Cardiac force-frequency relationship and frequency-dependent acceleration of relaxation are impaired in LPS-treated rats"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: Cardiac force-frequency relationship and frequency-dependent acceleration of relaxation are impaired in LPS-treated rats. | Available online http content 13 1 R14 Research Cardiac force-frequency relationship and frequency-dependent acceleration of relaxation are impaired in LPS-treated rats Olivier Joulin1 Sylvestre Marechaux2 3 Sidi Hassoun1 3 David Montaigne1 3 Steve Lancel3 and Remi Neviere1 3 1EA 2689 IMPRT-IFR114 Université de Lille 2 1 place de Verdun 59000 Lille France 2Service Explorations Fonctionnelles Cardiovasculaires CHRU Lille Bd Pr. Leclercq 59000 Lille France 3Département de Physiologie Faculté de Médecine 1 place de Verdun 59000 Lille France Corresponding author Remi Neviere rneviere@ Received 8 Oct 2008 Revisions requested 13 Jan 2008 Revisions received 17 Dec 2008 Accepted 6 Feb 2009 Published 6 Feb 2009 Critical Care 2009 13 R14 doi cc7712 This article is online at http content 13 1 R14 2009 Joulin et al. 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. Open Access Abstract Introduction Frequency-dependent acceleration of relaxation FDAR ensures appropriate ventricular filling at high heart rates and results from accelerated sarcoplasmic endoplasmic reticulum calcium ATPase SERCA activity independent of calcium removal from the cell. Because lipopolysaccharide LPS challenge may induce aberrations in calcium trafficking and protein phosphorylation we tested whether LPS would abolish FDAR in rats. Methods Following LPS injection changes in force-frequency relationship and FDAR were studied in cardiomyocytes isolated hearts and in vivo by echocardiography. Calcium uptake and phosphatase activities were studied in sarcoplasmic reticulum SR vesicle preparations. Western blots of phospholamban and calcium calmodulin-dependent protein kinase II and serine threonine phosphatase activity .