Parabronchial remodeling in chicks in response to embryonic hypoxia [RESEARCH ARTICLE]

Lara do Amaral-Silva, Markus Lambertz, Fernando Jose Zara, Wilfried Klein, Luciane Helena Gargaglioni, and Kenia Cardoso Bicego The embryonic development of parabronchi occurs mainly during the second half of incubation in precocious birds, which makes this phase sensitive to possible morphological modifications induced by O2 supply limitation. Thus, we hypothesized that hypoxia during the embryonic phase of parabronchial development induces morphological changes that remain after hatching. To test this hypothesis, chicken embryos were incubated entirely (21 days) under normoxia or partially under hypoxia (15% O2 during days 12 to 18). Lung structures, including air capillaries, blood capillaries, infundibula, atria, parabronchial lumen, bronchi, blood vessels larger than capillaries (Bv) and interparabronchial tissue (It), in 1- and 10-day-old chicks were analyzed using light microscopy-assisted stereology. Tissue barrier and surface area of air capillaries were measured using electron microscopy-assisted stereology, allowing for calculation of the anatomical diffusion factor. Hypoxia increased the relative volumes of air and blood capillaries, structures directly involved in gas exchange, while decreased the relative volumes of atria in both groups of chicks, and the parabronchial lumen in older chicks. Accordingly, the surface area of the air capillaries and the anatomical diffusion factor were increased under hypoxic incubation. Treatment did not alter total lung volume, ...
Source: Journal of Experimental Biology - Category: Biology Authors: Tags: RESEARCH ARTICLE Source Type: research