Background. We hypothesized that the addition of fructose 1,6-diphosphate (
FDP) to a hypothermic heart preservation solution could improve metabolic r
ecovery because it has several beneficial effects.
Materials and Methods. Twenty adult Sprague-Dawley rats were used to study
hypothermic heart preservation. The hearts were removed under general anest
hesia and preserved at 4 degrees C in Euro-collins solution (30 ml/kg) for
8 h. In the study group (N = 10), FDP (5 mM) was added to the Euro-Collins
solution. In the control group (N = 10), no FDP was added. Heart function w
as studied after preservation using a working heart model. The ability of v
arious concentrations of fructose 1,g-phosphate to passively diffuse throug
h an egg phosphatidylcholine multilamellar vesicle (MLV) membrane bilayer w
as examined.
Results. Cardiac output ranged from 17.0 +/- 1.9 to 24.9 +/- 1.6 ml/min in
the study group vs 2.0 +/- 1.0-12.3 +/- 1.7 ml/min for controls, average ao
rtic how was 10.8 +/- 1.4 ml/min in the study group vs -1.3 +/- 1.6 ml/min
for controls, and maximum LV generated power was 22.8 +/- 1.7 J/min vs 10.1
+/- 1.6 J/min for controls. Coronary how, left ventricular stroke volume a
nd stroke work, and myocardial oxygen consumption were much higher in the s
tudy group than in the control group. Coronary vascular resistance was lowe
r in the study group than in the control group. Electron microscopic study
indicated that many myocytes displayed patches of swollen mitochondria in t
he control group, but was rarely observed in the study group. The addition
of 50 mM FDP caused substantial changes in MLV permeability. No dose of suc
rose buffers outside the vesicles resulted in a significant changes of MLV
permeability.
Conclusions Our results indicate that the addition of FDP to Euro-Collins s
olution significantly improves hypothermic rat heart preservation, and FDP
appeared to cross the membrane bilayer. (C) 1999 Academic Press.