Immunohistochemical Study of Smooth Muscle Cells and Elastin in Goose Lungs

There are many differences (morphological, physiological and mechanical) between the lungs of birds and the lungs of mammals. Birds have a more efficient exchange of oxygen and carbon dioxide than mammals. In this article, we studied the presence of four antibodies (actin, α-smooth muscle actin, desmin and elastin) in the lungs of geese. Smooth muscle cells (SMCs) immunoreactive to actin, α-SMA and desmin were observed in the primary and secondary bronchi and arranged as a continuous layer. In the tertiary bronchus (parabronchus), immunoreactive cells on α-SMA and desmin were observed as aggregations of smooth muscle cells in the septum tips in atrial opening. A small number of α-SMA and desmin-positive cells were observed on the periphery of the parabronchi and between the air and blood capillaries. The elastic fibres were found in the large bronchi in connection with smooth muscle bands. In the parabronchi the elastic fibres form an elastic membrane lining the parabronchial lumen. In the blood vessels, the elastic fibres form the inner and outer elastic membrane. The individual elastic membranes connect neighbouring blood vessels.