Morphology of trachea of mature chickens, grown under the conditions of radioactive contamination

Abstract

The features of macro- and microscopic structure and morphometric parameters of the trachea of chickens of the Black Moscow breed of 180 days of age grown in conditionally pure and II zone of radioactive contamination are presented in the work using radiological, morphological, morphometric and statistical methods of research. It has been found that the presence of chickens in radioactively contaminated territories, feeding them with locally-sourced food, has an adverse effect on the respiratory organs, including the trachea. According to the results of radiological research, the increase of gamma background was established in the territory where the experimental part of the research was conducted. Thus, according to our observations, the specific power of the exposure dose of gamma rays for cesium-137 in the territory where the experimental animals were kept was almost in 3–3.5 times higher than this indicator for the relatively pure radioactive contamination of the territory. The specific activity of the diet for cesium-137 in chickens of 180 days of the experimental group was almost 8.5 times higher than in the control group of animals and was 13.4–16.0 Bq/kg, compared with the control (1.64–1.82 Bq/kg), indicating the cumulative capacity of this isotope. According to our research, the trachea of chickens of the experimental group has a pale pink color and is built of cartilage rings (110–120 units), which have a rounded shape. Its wall is formed by the mucous and fibrous cartilage and adventitia. The mucous membrane has a folded structure and is lined with multilayered ciliated epithelium and contains glands. Four types of cells are well differentiated into the epithelium: basal, ciliated, endocrine, and goblet. The fibrous cartilage sheath is formed by tracheal cartilages, which are interconnected by a dense fibrous connective tissue. The histoarchitectonics of the trachea of chickens reared in the second zone of radioactive contamination is similar to that of chickens in the control group. However, our morphometric studies noted that the animals of the experimental group increased the size of the terminal parts of the tracheal glands, thickened connective tissue capsules of the lymph nodes. The absolute body mass of the chickens of the experimental group, compared with the control group, tends to decrease and is respectively 2.96 ± 0.19 g, while the relative weight of the organ significantly (P ≤ 0.001) decreases to 0.284 ± 0.027%. In addition, for 180-day-old chickens that were constantly under radioactive contamination, the thickness of the mucous, fibrous, cartilage, and adventitious membranes tended to decrease compared to chickens from the conditionally clear area for radioactive contamination.