Attenuation of Verapamil-induced Myocardial Toxicity in an Ex-vivo Rat Model Using a Verapamil-specific Ovine Immunoglobin
Article first published online: 28 JUN 2008
Academic Emergency Medicine
Volume 8, Issue 10, pages 950–955, October 2001
How to Cite
Hill, R. E., Heard, K., Bogdan, G. M., Cairns, C. B. and Dart, R. C. (2001), Attenuation of Verapamil-induced Myocardial Toxicity in an Ex-vivo Rat Model Using a Verapamil-specific Ovine Immunoglobin. Academic Emergency Medicine, 8: 950–955. doi: 10.1111/j.1553-2712.2001.tb01092.x
- Issue published online: 28 JUN 2008
- Article first published online: 28 JUN 2008
- received February 15, 2001 revision received May 29, 2001 accepted June 11, 2001.
- calcium channel blockers;
- papillary muscles
Objective: To determine whether an ovine verapamil-specific immunoglobin G (V-IgG) attenuates verapamil toxicity in an ex-vivo rat left ventricular papillary muscle model. Methods: The authors dissected left ventricular papillary muscle strips from male Sprague-Dawley rats (350-410 g) and suspended them in an oxygen-perfused Tyrode buffer bath at 37.5°C. Muscle strips equilibrated for 90 minutes under electrical stimulation of 1 Hz. Resting and developed tension (mg) were monitored continuously. A concentration—response trial was performed with verapamil concentrations ranging from 31 to 1,020 nM; 510 nM produced consistent reduction in developed tension. A trial of V-IgG was then conducted by administering the following treatments to papillary muscle strips in a randomized manner: V-IgG + 510 nM verapamil, nonspecific ovine IgG (N-IgG) + 510 nM verapamil (protein control), and 510 nM verapamil alone. Immunoglobin G was administered in equimolar concentrations to verapamil. Attenuation was expressed as inhibition of the verapamil-induced reduction of developed tension. Results: The V-IgG comparative trial indicated the V-IgG + verapamil treatment had a mean reduction in developed tension of 14.1% (SD ± 12.2) compared with 36.2% (SD ± 14.9) for N-IgG + verapamil and 34.9% (SD ± 8.1) for verapamil alone (p < 0.05). There was no difference between the two control groups. Conclusion: Verapamil-specific IgG attenuated verapamil-induced reduction of developed tension in an ex-vivo rat model.