Perfil leucocitário e anomalias nucleares eritrocitárias em Antilophia galeata (Passeriformes: Pipridae) no biomonitoramento ambiental de fragmentos florestais do Cerrado

Abstract

Birds are model organisms for environmental biomonitoring studies due to their sensitivity to anthropogenic changes, such as pollution. Hematological analyses, including erythrocyte nuclear abnormalities and leukocyte profile, are frequently used in biomonitoring. Nuclear abnormalities form when organisms are exposed to xenobiotics, leading to genotoxic effects that interfere with the structure or function of the mitotic apparatus. The leukocyte profile consists of quantifying leukocytes, which include different cell types that provide protection against pathogens and environmental stressors. The amount and proportion of leukocytes can change by stress hormone concentrations, the corticosteroids. When present at high levels, these hormones increase the number of heterophils and decrease the number of lymphocytes, resulting in higher heterophil lymphocyte (H/L) ratio, which characterize the leukocyte stress profile. This study aimed to verify whether there is a correlation between nuclear abnormalities and the leukocyte profile in Antilophia galeata (Cerrado’s endemic species) according to urbanization levels. 74 individuals were captured in four forested areas, two rural and two peri-urban. Blood samples were collected to prepare blood smears, which were later analyzed under an optical microscope. The leukocytes (heterophils, lymphocytes, eosinophils, monocytes and basophils) were identified and quantified. Five types of nuclear abnormalities were quantified: erythroplastid, asymmetric constriction, symmetric constriction, slotted nucleus, and binucleate cell. The mean number of total abnormalities, total leukocytes, and H/L ratio in birds from rural areas were 1.58±1.93, 59.3±50.8, and 0.42±0.82, respectively, while in peri-urban areas, these values were 1.91±1.88, 45.8±53.1, and 0.88±1.14, respectively. Positive correlations were found between erythroplastid and total leukocytes, as well as between asymmetric constriction and H/L ratio in birds from peri-urban areas. In rural areas, a negative correlation was observed between slotted nucleus and total leukocytes. The observed correlations indicate that birds may be responding to environmental stressors in the studied areas. Finally, this study demonstrated the sensitivity of Antilophia galeata to environmental changes and conditions, and the results may be valuable for future studies related to environmental, animal, and human health.