To create a three-dimensional (3-D) image of the blood vessels in the observed area by endoscopy, we fluorescently labeled the gastric blood vessels using tomato lectin [Lycopersicon esculentum agglutinin (LEA)].22–25 LEA can selectively label vascular endothelial cells. To label the swine gastric vessels, we developed a method to administrate LEA to gastric vessels only. The abdomen was opened to expose the whole stomach, and then a cannula was inserted into the left gastric artery for agent injection. The left gastric vein was clamped, and the left and right gastroepiploic arteries, right gastric artery and vein, and short gastric artery and vein were ligated. A cannula for drainage was inserted into the left gastric vein. Next, 12 mg of FITC-labeled LEA (FL-1171, Vector Laboratories) was injected into the left gastric artery. Approximately 5 min later, the left gastric vein was released, and then 500 mL of PBS containing 4% paraformaldehyde was administered through the injection cannula for perfusion fixation of all gastric tissues and also to flush away the residual LEA in the blood. After fixation, the pig was euthanized by exsanguination of the abdominal aorta. The stomach was removed and cut open from the greater curvature, and then the tissue of the observed area was extracted. The excised tissue was immersed in a sucrose solution overnight, and then -thick cryostat sections were prepared. We observed the sections with a confocal laser microscope (LSM 780, Zeiss) at magnification, using an argon laser (488 nm) for FITC excitation. We obtained cross-sectional images at steps of .