L-Arginine polymers enhance coronary flow and reduce oxidative stress following cardiac transplantation in rats.

Background: Hearts treated with l-arginine polymers have demonstrated upregulated production of nitric oxide. The current study examined whether these polymers improved coronary flow and reduced myocardial oxidative stress after rat heart transplantation.

Methods: PVG donor hearts were incubated ex vivo with either 100 mumol/L l-arginine polymers 9 amino acids in length (R9) (n = 7) or phosphate-buffered saline (n = 7) for 30 minutes after arrest and then transplanted heterotopically into the abdomen of ACI recipient rats.

Comparison of developmental endothelial locus-1 angiogenic factor with vascular endothelial growth factor in a porcine model of cardiac ischemia.

Background: This study compared the angiogenic effects of developmental endothelial locus-1 (DEL-1), vascular endothelial growth factor (VEGF), as well as the negative control, beta-galactosidase (beta-gal), in a porcine model of cardiac ischemia.

Methods: Twenty pigs underwent left circumflex artery occlusions. After 3 weeks, the animals received myocardial injections of adenovirus expressing beta-gal (n=6), DEL-1 (n=7), or VEGF (n=7).

Bcl-2-mediated inhibition of apoptosis in rat cardiac allografts worsens development of graft coronary artery disease.

Background: We hypothesized that adenovirally mediated Bcl-2 transfection of donor hearts would reduce the apoptosis that occurs during acute rejection while worsening the development of chronic graft coronary artery disease (GCAD).

Methods: PVG donor hearts were treated with either AdvBcl-2 or AdvNull virus before heterotopic transplantation into ACI rats. Bcl-2 expression was assessed on post-operative day 4 (POD) 4 by western blot.

The use of (99m)technetium-labeled MCP-1 to assess graft coronary artery disease in rat cardiac allografts.

Background: Monocyte chemoattractant protein-1 (MCP-1) is associated with the development of graft coronary artery disease (GCAD) following cardiac transplantation. This study assessed whether technetium 99m ((99m)Tc)-labeled MCP-1 binds its receptors in chronic cardiac transplants and thereby provides a potential modality to assess GCAD.

Methods: Allogeneic (PVG-->ACI, n = 9) and syngeneic (ACI-->ACI, n = 9) rat heterotopic heart transplants were performed.

Zinc chloride-mediated reduction of apoptosis as an adjunct immunosuppressive modality in cardiac transplantation.

Background: Zinc (Zn) blocks caspase-3 activation in cardiac allografts and therefore may synergistically decrease apoptosis along with cyclosporine (CsA), which inhibits mitochondrial release of cytochrome c. Simultaneous treatment of rat recipients of heterotopic heart transplants with zinc chloride (ZnCl(2)) thus may allow lower doses of CsA for immunosuppression.

Methods: PVG (RT1(c)) rat hearts were transplanted heterotopically into the abdomen of ACI (RT1(a)) rats.