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.

MATERIALS AND 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: Justin Sambol, Edwin A Deitch, Koichi Takimoto, Garima Dosi, Atsuko Yatani
• Journal: The Journal of surgical research (J Surg Res) Vol. 183 Issue 2 Pg. 678-85 (Aug 2013) ISSN: 1095-8673 [Electronic] United States
• PMID: 23465433 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: Copyright © 2013 Elsevier Inc. All rights reserved.

Chemical References

• Calcium Channels, L-Type

Topics

• Animals
• Burns (complications)
• Calcium Channels, L-Type (physiology)
• Cell Size
• Heart (physiopathology)
• In Vitro Techniques
• Ligation
• Lymphatic System (physiopathology)
• Male
• Mesentery (physiopathology)
• Models, Animal
• Myocardial Contraction (physiology)
• Myocytes, Cardiac (pathology, physiology)
• Rats
• Rats, Sprague-Dawley
• Signal Transduction (physiology)
• Time Factors