Leukocyte Behavior in Mesenteric Microcirculation upon Exper-imental By Leishmania Spp. in BALB/c Mice

Background: We aimed to determine the cellular recruitment (leukocyte rolling and adhesion) by which the Leishmania (Viannia) braziliensis, L. (Leishmania) amazonensis, and L. (Leishmania) major species in the mesenteric microcirculation of BALB/c mice. Methods: Five experimental groups were considered: group 1 (L. braziliensis); group 2 (L. amazonensis); group 3 (L. major); group 4 (control group with PBS); group 5 (negative control group), analyzed 3, 6, 12, and 24 h after parasite inoculation. Results: Infections by the different Leishmania species caused an increase in the number of rolling leukocytes: L. braziliensis a peak at 6 h; L. amazonensis and L. major a peak at 3 h. The Leishmania infections induced leukocyte adhesion: L. major and L. amazonensis showed an increase after 3 and 6 h, respectively. Conclusion: The kinetics of cellular recruitment in Leishmania infections, leading to infection susceptibility or resistance, indicates that distinct mechanisms regulate the initial response to Leishmania infection and determine its course.