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:" Vitamin A deficiency alters the pulmonary parenchymal elastic modulus and elastic fiber concentration in rats. | Respiratory Research BioMed Central Research Open Access Vitamin A deficiency alters the pulmonary parenchymal elastic modulus and elastic fiber concentration in rats Stephen E McGowan Erika J Takle and Amey J Holmes Address Department of Veterans Affairs Research Service and Department of Internal Medicine Roy A. and Lucille J Carver College of Medicine University of Iowa Iowa City IA USA Email Stephen E McGowan - stephen-mcgowan@ Erika J Takle - erika-takle@ Amey J Holmes - amey-holmes@ Corresponding author Published 20 July 2005 Received 01 February 2005 Respiratory Research 2005 6 77 doi 1465-9921 -6-77 Accepted 20 July 2005 This article is available from http content 6 1 77 2005 McGowan 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. Abstract Background Bronchial hyperreactivity is influenced by properties of the conducting airways and the surrounding pulmonary parenchyma which is tethered to the conducting airways. Vitamin A deficiency VAD is associated with an increase in airway hyperreactivity in rats and a decrease in the volume density of alveoli and alveolar ducts. To better define the effects of VAD on the mechanical properties of the pulmonary parenchyma we have studied the elastic modulus elastic fibers and elastin gene-expression in rats with VAD which were supplemented with retinoic acid RA or remained unsupplemented. Methods Parenchymal mechanics were assessed before and after the administration of carbamylcholine CCh by determining the bulk and shear moduli of lungs that that had been removed from rats which were vitamin A deficient or received a control diet. Elastin mRNA and insoluble elastin were quantified and elastic fibers were .
