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J Clin Exp Tox 2017 | Volume 1 | Issue 2
Toxicology and Pharmacology
November 01-02, 2017 | Toronto, Canada
International Conference on
Purpose:
Heart transplantation is one of the most effective
treatment options for congestive heart failure. Current
organ storage methods can preserve the human heart
for only about four to six hours. The organ donor pool
could be dramatically increased if the preservation time
could be lengthened and hearts stored for weeks or even
months prior to transplantation. This study describes the
performance characteristics of explanted Sprague-Dawley
rat hearts before and after cryopreservation using 10%
dimethylsulphoxide (DMSO) and 30% dimethylformamide
(DMF) in Tyrode solution.
Methods:
A modified Morgan perfusion model was used
for this study. Male Sprague- Dawley (ethical approval
AREC/2009/09/002) hearts were harvested and arrested in
a cold (<10°C) Tyrode solution (pH 7.4) for 5 minutes. The
hearts were mounted on the aorta and vena cava to allow
reperfusion in a doubled walled water jacket at 37 °C for
baseline performance studies. The hearts (n=3) were cooled
to 4, -20, -80 and -196°C (liquid nitrogen), and stored for 6
hours. This study was extended to 48 hours and 7 days at
-196 °C (n=6). Cardiac output (aortic and coronary) and an
electrocardiogram were obtained during baseline studies,
followed by cryopreservation and after thawing at times T0,
10, 20, 40, 60, 120 min, 6, 8, 12 and 24 hours. Reperfused
heartsweremonitored for as longas possible. Ethical approval
(AREC/2009/09/002) for the use of laboratory animals
was obtained from the Tshwane University of Technology,
Ethics Committee and the Animal Ethics committee before
experimental work commenced.
Discussion:
The average heart rate of the Sprague-Dawley
rats reduced from 396 beats/minutes to 184 beats/minutes
after anaesthesia. The average survival time of the hearts
under the experimental conditions were seven hours 32
minutes with an average aortic output at 8 hours of 0.62 ml
and 0.52 ml at 12 hours for DMF and 0.61 ml for 8 hours
and 0.35 ml for DMSO at average survival time of 9 hours
44 minutes. A 100 % recovery after cryopreservation with
DMSO and DMF was achieved after storage for 6 hours, 48
hours and 7 days in liquid nitrogen. DMSO and DMF were
equally effective cryoprotectants in this study.
Conclusion:
It was possible to preserve the hearts outside
the body longer than eight hours as previously studied to
168 hour (7days) at –196°C with 100% recovery using both
DMSO and DMF as cryoprotectant.
e:
jocs_scoj@yahoo.comComparative performance of Sprague-Dawley rat hearts using DMSO and DMF as cryoprotectants
Jones Ozokwere, Lynton Hazelhurst, Eugene Olivier
and
Maupi Letsoalo
Tshwane University of Technology, South Africa