02802nas a2200349   4500000000100000008004100001260001600042653001200058653001500070653003200085653002600117653001600143653002100159653001100180653002400191653001300215653001200228653001400240653004400254653001600298653002100314653001700335100002100352700002000373700002000393700002100413245011800434300001100552490000800563520186700571022001402438       2005                            d  c2005 Jul 1510aAnimals10aArmadillos10aBlood Bactericidal Activity10aChemotaxis, Leukocyte10aEndocytosis10aEscherichia coli10aHumans10aIn Vitro Techniques10aKinetics10aleprosy10aMonocytes10aN-Formylmethionine Leucyl-Phenylalanine10aNeutrophils10aOpsonin Proteins10aPhagocytosis1 aLópez-Hurtado M1 aFlores-Medina S1 aDíaz-García F1 aGuerra-Infante F00aPartial characterization of phagocytic activity in neutrophils of the nine-banded armadillo Dasypus novemcinctus.  a269-750 v1063 a<p>Though the armadillo is important as a research model in leprosy studies, the activity of armadillo's neutrophils is an aspect of little research. The aim of this study was carried out to partially characterize the chemotaxis, endocytosis and bacteriocidal ability of the neutrophils found in the nine-banded armadillo (Dasypus novemcinctus). Results showed that the chemotactic activity of the neutrophils, evaluated by the movement of the neutrophils through a nitrocellulose membrane (5 microm) in response to a chemo-attractive substance, was greater towards the armadillo serum (5.16+/-1.35 migration index, p<0.05) than towards the formil methionyl leucil phenylalanine (fMLP, 1.43+/-0.18 migration index) or human serum (0.56+/-0.18 migration index). Regarding endocytic capacity of the neutrophils and the monocytes against Escherichia coli was evaluated by a flow cytometry and using opsonized and non-opsonized E. coli-FITC at the following incubation times: 5, 10, 20, 30 and 60 min. The largest percentage of endocytosis by the neutrophils was 92.32+/-0.12% with opsonized bacteria and 77.73+/-14.33% with non-opsonized bacteria at 10 min incubation time, while the largest percentage of endocytosis by monocytes was 89.94+/-1.40% with opsonized bacteria and 73.07+/-15.6% with non-opsonized bacteria at 20 min incubation time. Evaluation of the bacteriocidal capacity of neutrophils using the methyl-thiazol-tetrazolium salts (MTT) reduction color-measurement assay showed an 89.0+/-10% mortality rate of non-opsonized E. coli and 89.0+10% of opsonized E. coli. In conclusion, the armadillo neutrophils show a good phagocytosis and bacteriocidal activity; however, a deficiency in the migration towards the fMLP was observed. This deficiency could be a cause so that the armadillo neutrophils do not respond quickly to invading microorganism.</p>  a0165-2427