Experimental small bowel transplantation using newborn intestine in rats: II. Revascularization of newborn intestine is independent of vascular endothelial growth factor.

BACKGROUND

Fetal and newborn intestine often are revascularized after subcutaneous transplantation without surgical vascular anastomosis. However, the mechanism of this ability remains unclear.

METHODS

First, the ability of natural revascularization in newborn organs was tested. Newborn organs in whole (liver, kidney, heart, intestine, spleen, and pancreas) were grafted i nto the subcuta neous tissue of the adult rat and evaluated histopathologically 2 weeks after transplantation. Second, expression of vascular endothelial growth factor (VEGF) mRNA in the intestinal graft was determined before and after transplantation. Finally, we tested whether the free graft survival of newborn intestine was interrupted by TNP-470, an antiangiogenic agent.

RESULTS

Spleen and intestine were revascularized at a higher rate (91.6%, 75%, respectively), and kidney and heart grafts survived at a lower rate (41.7%, 25%, respectively). But all of liver and pancreas grafts failed to be revascularized. VEGF mRNA was not induced in the course of revascularizing. Furthermore, TNP-470 did not interfere with neovascularization of the newborn intestinal graft in vivo.

CONCLUSIONS

Each organ had an organ-specific angiogenic activity. Neovascularization of intestinal graft was not dependent on VEGF expression.