Please cite this paper as: Jin X-L, Li X-H, Zhang L-M, Zhao J. The interaction of leukocytes and adhesion molecules in mesenteric microvessel endothelial cells after internal capsule hemorrhage. Microcirculation similar to 19: 539546, 2012. Abstract Objective: To explore the correlation between hemorheological variations and the expression of cell adhesion molecules in mesenteric microvessel endothelial cells after internal capsule hemorrhage. Methods: We established an internal capsule hemorrhage model. Then leukocyteendothelium interaction was observed and hemorheological variations in mesenteric microvessels were evaluated in the following aspects: blood flow volume, diameter of microvessels, blood flow rate, and shear rate. We also measured the expression of vascular cell adhesion molecule-l and intercellular adhesion molecule-1 (ICAM-1) in mesenteric microvessel endothelial cells with immunohistochemistry stain. Results: Leukocyteendothelium interaction intensified after internal capsule hemorrhage. Besides, blood flow volume and velocity decreased, diameter narrowed, and shear rate reduced. Immunohistochemical staining of vascular cell adhesion molecule-l and ICAM-1in mesenteric microvessel endothelial cells was stronger. Conclusions: VCAM-1 and ICAM-1 expression in mesenteric microvessels increased as a result of decreased wall shear stress in stress state following internal capsule hemorrhage, and then further shear stress change from interaction of enhanced production of CAMs and leukocytes created a vicious cycle of leukocytes margination, adhesion, and transmigration that could ultimately result in stress gastrointestinal ulcer.