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 subc utaneous transplantation without surgical vascular anastomosis. However, th e mechanism of this ability remains unclear. Methods: First, the ability of natural revascularization in newborn organs was tested. Newborn organs in whale (liver, kidney, heart, intestine, splee n, and pancreas) were grafted into the subcutaneous tissue of the adult rat and evaluated histopathologically 2 weeks after transplantation. Second, e xpression of vascular endothelial growth factor (VEGF) mRNA in the intestin al graft was determined before and after transplantation. Finally, we teste d whether the free graft survival of newborn intestine was interrupted by T NP-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 (4 1.7%, 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 new born intestinal graft in vivo. Conclusions: Each organ had an organ-specific angiogenic activity. Neovascu larization of intestinal graft was not dependent on VEGF expression. J Pedi atr Surg 34:1396-1400. Copyright (C) 1999 by W.S. Saunders Company.