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ALTERATION OF CARDIAC ELECTRICAL ACTIVITY BY WATER-LEACHABLE COMPONENTS OF RESIDUAL OIL FLY ASH (ROFA)
Citation:
Wang, D., A. Xie, T. Wang, AND Huang, YuhChin T. ALTERATION OF CARDIAC ELECTRICAL ACTIVITY BY WATER-LEACHABLE COMPONENTS OF RESIDUAL OIL FLY ASH (ROFA). Presented at Experimental Biology Meeting, Washington, DC, April 17-21, 2004.
Description:
Alteration of cardiac electrical activity by water-leachable components
of residual oil fly ash (ROFA)
Desuo Wang, Yuh-Chin T. Huang*, An Xie, Ting Wang
*Human Studies Division, NHEERL, US EPA
104 Mason Farm Road, Chapel Hill, NC 27599
Department of Basic Pharmaceutical Sciences, College of Pharmacy,
University of South Carolina, Columbia, SC 29208, USA
The effects of water-leachable components of ROFA (a laboratory surrogate for airborne particulate maters, PM) on atrial electrograms and action potential parameters were studied in isolated perfused rat hearts as well as guinea pig ventricular myocytes. The extraction was performed using dd-H2O (4 mg ROFA per ml) and a 40,000g-centrifuge supernatant was used as stock solution. Addition of the extract to K-H perfusate (1:1000 and 1:100 dilution, respectively) dose-dependently slowed the sinoatrial rate in Langendorff-perfused spontanousely beating hearts by 9.2 % and 52.4 %, respectively. Heart rate variability (SDNN) was increased from 5.6 to 46.9 msec and atrioventricular nodal conduction time was increased from 40.8 to 58.1 msec when high dose was used (1:100). The extract (dilution of 1:1000 and 1:100) markedly shortened the action potential duration of guinea pig ventricular myocytes in nystatin-perforated current patch-clamp mode. The high concentration also caused a notable depression of the plateau phase. These findings for the first time demonstrate that ROFA PM can directly affect the electrical activity of myocardium, which may underlie the toxic impact of ambient PM on human hearts. (This is a proposed presentation and does not necessarily reflect EPA policy).