title: Secondhand Smoke Exposure Enhances Cardiac Fibrosis Effects on the Aging Rat Hearts.
abstract: BACKGROUND
  Examining aging rats exposed to secondhand smoke (SHS) engenders changes in left ventricular remodeling due to age- or disease-dependent alterations.
  
  
  METHODS
  Rats were placed in whole-body exposure chambers and exposed to 10 cigarettes. Filtered air was introduced into the chamber at a low rate. Rats were exposed to SHS for 30 min, twice a day, 5 days per week for 1 month. After 4 weeks SHS exposure, rats were sacrificed for morphological study with trichome staining and left ventricular remodeling related protein analysis using western blot.
  
  
  RESULTS
  Characteristic fibrotic morphology in the left ventricle increased significantly with aging and exposure to SHS. Exposure to SHS elevated TGFβ1/p-Smad2/3/CTGF and MMP2/MMP9 protein expression levels (p < 0.05). No significant differences in FGF-2 and UPA protein expression were noted as a result of SHS exposure. However, TIMP-1, TIMP-2, TIMP-3 and TIMP-4 protein expression were suppressed by SHS exposure. We also observed increased TGFβ1/p-Smad2/3/CTGF (p < 0.01), FGF-2/UPA (p < 0.05) and decreased TIMPs protein expression levels. Corresponding MMP2 and MMP9 upregulation occurred with aging and exposure to SHS. TGFβ1/p-Smad2/3/CTGF and FGF-2/UPA protein expression from SHS exposure were higher than that from aging. In contrast, MMP2 and MMP9 were increased in aging rats compared with SHS exposed rats (p < 0.05); however, TIMP-1 (p < 0.01), TIMP-2 (p < 0.01) and TIMP-3 (p < 0.05) were decreased. TIMP-4 protein expression levels were decreased compared with SHS exposed rats (p < 0.01).
  
  
  CONCLUSIONS
  Aging and SHS exposure in rats will produce elevated fibrosis. Exposure to SHS will accelerate aging and left ventricular fibrosis.
authors.affiliation: Graduate Institute of Basic Medical Science, China Medical University.
authors.forename: Jia-Ping
authors.initials: JP
authors.lastname: Wu
authors.affiliation: Department of Healthcare Administration, Asia University, Taichung.
authors.forename: Shu Nu
authors.initials: SN
authors.lastname: Chang-Lee
authors.affiliation: Department of Nursing, MeiHo University, Pingtung.
authors.forename: Cecilia Hsuan
authors.initials: CH
authors.lastname: Day
authors.affiliation: Graduate Institute of Chinese Medicine, China Medical University, Taichung; ; Chinese Medicine Department, China Medical University Beigang Hospital, Taiwan.
authors.forename: Tsung-Jung
authors.initials: TJ
authors.lastname: Ho
authors.affiliation: Department of Biotechnology, Bharathiar University, Coimbatore, India.
authors.forename: Vijaya Padma
authors.initials: VP
authors.lastname: Viswanadha
authors.affiliation: Department of Hospital and Health Care Administration, Chia Nan University of Pharmacy & Science, Tainan County.
authors.forename: Li-Chin
authors.initials: LC
authors.lastname: Chung
authors.affiliation: School of Applied Chemistry, Chung Shan Medical University.
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Hwang
authors.affiliation: Division of Cardiology, Armed Force Taichung General Hospital.
authors.forename: Gwo-Ping
authors.initials: GP
authors.lastname: Jong
authors.affiliation: Department of Biological Science and Technology, China Medical University.
authors.forename: Wei-Wen
authors.initials: WW
authors.lastname: Kuo
authors.affiliation: Graduate Institute of Basic Medical Science, China Medical University; ; Graduate Institute of Chinese Medicine, China Medical University, Taichung; ; Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan.
authors.forename: Chih-Yang
authors.initials: CY
authors.lastname: Huang
keywords: Aging; Basic fibroblast growth factors; Connective tissue growth factor; Extracellular matrix; Secondhand smoke exposure