title: Cellular basis of burn-induced cardiac dysfunction and prevention by mesenteric lymph duct ligation.
abstract: BACKGROUND
  Myocardial contractile depression develops 4 to 24 h after major burn injury. We have reported previously that in a rat burn injury model (≈40% of total body surface area burn), mesenteric lymph duct ligation (LDL) prior to burn prevented myocardial dysfunction. However, the underlying cellular and molecular mechanisms are not well understood.
  
  
  METHODS
  Left ventricular myocytes were isolated from sham burn (control), sham burn with LDL (sham + LDL), burn, and burn with LDL (burn + LDL) rats at 4 and 24 h after burn or sham burn. Electrophysiological techniques were used to study myocyte size, contractility and L-type Ca2+ channel current (ICa). Further studies examined changes in the messenger RNA expression levels of pore-forming subunit of the L-type Ca(2+) channel, α1C, and its auxiliary subunits, β1, β2, β3, and α2δ1, which modulate the abundance of the ICa in post-burn hearts.
  
  
  RESULTS
  Depressed myocyte contractility (≈20%) developed during 4 to 24 h post-burn compared with control, sham + LDL, or burn + LDL groups, a pattern of changes consistent with whole heart studies. There was no significant alteration in myocyte size. The ICa density was significantly decreased (≈30%) at 24 h post-burn, whereas the messenger RNA expression levels of Ca(2+) channel gene were not significantly altered at 4 and 24 h after burn injury.
  
  
  CONCLUSIONS
  These results suggest that the post-burn contractile phenotype in vivo was also present in isolated myocytes in vitro, but cellular remodeling was not a major factor. The results also suggest that changes in ICa regulation, but not from Ca(2+) channel gene modification, may be a key element involved in post-burn contractile depression and the beneficial effects of LDL.
authors: Department of Surgery, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, NJ 07103, USA.
authors: Justin
authors: J
authors: Sambol
authors: Edwin A
authors: EA
authors: Deitch
authors: Koichi
authors: K
authors: Takimoto
authors: Garima
authors: G
authors: Dosi
authors: Atsuko
authors: A
authors: Yatani
mesh_terms: D000818:Animals; D002056:Burns / Q000150:complications*; D020746:Calcium Channels, L-Type / Q000502:physiology; D048429:Cell Size; D006321:Heart / Q000503:physiopathology*; D066298:In Vitro Techniques; D008026:Ligation; D008208:Lymphatic System / Q000503:physiopathology*; D008297:Male; D008643:Mesentery / Q000503:physiopathology*; D023421:Models, Animal; D009200:Myocardial Contraction / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000473:pathology* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000502:physiology; D013997:Time Factors
chemical_list: D020746:Calcium Channels, L-Type
keywords: Burn injury; Cardiac myocyte; L-type Ca(2+) channel; Mesenteric lymph ligation