Dose and time-dependent effects of glucocorticoid: A morphologic and morphometric study in the broiler lung

Authors: RAFIQUL ISLAM, NASRIN SULTANA, RAFIQUL ALAM, ANTORA AKTER, MD. ANISUZZAMAN, ZIAUL HAQUE, MD. ABU HADI NOOR ALI KHAN

Abstract: Glucocorticoids (GCs) play a critical function in neonatal lung growth and maturation though the long-term dose-dependent effects of GCs on lungs are still ambiguous. The purpose of the present study is to explore the morphologic and morphometric changes in broiler lungs in reaction to dietary GC. Day-old chicks (DOCs) were purchased and divided into four groups at random i.e. one control group (C) and three experimental groups (E1, E2, and E3). Commercial broiler feed was provided to both the control and experimental groups where the feed of the experimental groups contained GC, dexamethasone (DEX) at the rate of 3, 5, and 7 mg/ kg in E1, E2, and E3 groups, respectively. Lung (left) samples were collected on days 7, 14, 21, and 28. After recording the gross morphologic and morphometric data, the tissue samples were processed for histological investigation. In the gross morphological study, congested lung with reddish to blackish discoloration was seen in experimental broilers. The gross morphometric study revealed a significant decrease in weight, length, and width of the lung. In the histomorphologic study, the lung of experimental broilers revealed vascular and parabronchial lumen congestion. Mild to the severe edematous lesion was also found evident along with the absence of distinguishable inter parabronchial septa. Degeneration of lung parenchyma with the appearance of lipid droplets, inflammatory cell infiltration, and fibrosis was seen to some extent. The histomorphometric investigation revealed a significant decrease in the diameter of the parabronchus as well as the thickness of the parabronchial wall. The study results suggest that dexamethasone may adversely alter the gross and histological characteristics of broiler lungs.

Keywords: Glucocorticoid, dexamethasone, broiler, lungs, morphology, morphometry

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