Objective: This study examined the changes in myocardial calcium transport function and what roles it played in cardiac dysfunction after severe burn injury.
Methods: Contraction relaxation properties of the left ventricule (LV) were studied in isolated heart preparations of Wistar rat 3, 8, 24 hours after 30% TBSA full thickness burn. Sarcoplasmic reticulum (SR) calcium transport function was measured by millipore filtration technique.
Results: The maximal rates of LV pressure elevation (+ dp/ dtmax) and depression (-dp/dtmax) in burn group were significantly lower than that in control group (P < 0.01). The initial rate and capacity of calcium uptake by SR decreased markedly in burn group than in control group (P < 0.01). In addition, calcium dependent ATPase activity and coupling ratio of SR were also markedly depressed.
Conclusion: SR calcium transport function depression was closely related to cardiac contractile dysfunction, and the former is one of the important mechanism for cardiac contractile dysfunction after severe burn injury.