Can Metabolic Biomarkers of Oxygen- Dependent Processes Determine Health Status of Pigeon Columba Livia F. Urbana?

Abstract

Background/aims: Anthropogenic impact is irreversibly changing natural habitats of birds. Changes caused by the bioaccumulation of trace metals can lead to the development of oxidative stress and affect oxygen-dependent metabolic pathways in bird tissues, which can be used as effective bioindicators in these conditions. The objectives of our study were (a) to investigate the tissue-specific activity of key enzymes involved in metabolic changes and energy production, including Krebs cycle enzymes, as well as variations in metabolites associated with oxygen-dependent processes; and (b) to apply multivariate regression analysis, using beta and correlation coefficients, to elucidate the mechanisms of adaptive responses in pigeons to environmental changes in lead-contaminated areas.

Methods: This study investigates the ecotoxicological effects on feral pigeons (Columba livia f. urbana) in their natural habitats. It examines the influence of key environmental factors, sex, and biochemical alterations across five tissues (liver, kidney, heart, muscle, and brain). The analysis includes the combined effects of these variables on biochemical biomarkers related to energy metabolism, oxidative stress, and antioxidant defenses, considering the levels of chemical elements present in the pigeons. The analyses involved two groups of pigeons, namely, 7 females and 10 males (n = 17) in the group sampled in Słupsk and 7 females and 7 males, (n = 14) in Szpęgawa that living in two areas in central part of Northern Poland, which differed in the level of anthropopressure.

Results: We report significant values of lead bioaccumulation in feathers of pigeons and the impact of this metal on the activities of Krebs cycle enzymes (succinate dehydrogenase, pyruvate dehydrogenase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase), biomarkers of oxygen-dependent processes (lactate dehydrogenase activity, lactate and pyruvate levels, and their ratio), and aminotransferases in different tissues of pigeons.

Conclusion: Biomarkers of oxygen-dependent processes in five tissues of pigeons are depending on sex and environment. Pigeons from lead-exposed areas exhibited decreased antioxidant defence by biochemical alterations in tissues. Analytical model of oxidative stress biomarkers, Krebs cycle enzymes, and chemical elements is significant. Using multivariate regression analysis with beta- and correlative coefficients, relationships were shown for the optimal development of adaptation alterations in biochemical reactions in pigeons in response to the modification of their environments. Research on Columba livia f. urbana provides valuable insights into understanding the effects of anthropogenic pollution on bird physiology and offers practical methods for assessing environmental health.