Comparative Studying On Structure Of Pulmonary And Pulmonary Arteries Wall Of Tibetan Mastiff Living At Different Altitudes

The Structural of pulmonary tissue and the characteristic pulmonary arteries wall of 10 Tibetan Mastiffs from Lanzhou area and Dari country of Guoluo Prefecture of Qinghai Province were studied by light and trans electro-microscopy observation and morphologic measurement. The purpose is to investigated the fine structure of the Tibetan Mastiffs lung and how it adapted to the plateau. The main results were shown as following:The pulmonary pleura is very thick and there are many collagenous fibers with elastic fibers in the pleura. The walls of bronchi and bronchioli are thick because of there are a lot of elastic fibers have been found in proper coat and tunica externa. It is the histological characteristic of respiratory portion that the numbers of alveolar ducts are great many. Each respiratory bronchiole breaks up abundant generous alveolar ducts. A Lot of smaller and collapsed pulmonary alveolus have been observed surrounding the alveolar ducts. There are rich dilating capillaries which contained many red cells were found. The intrapulmonary mast cells relative less and they often appearce spherical or orbicular-ovate have lots of larger blue particles inside the intracytoplasm or extracellular. They have been shown to mainly reside in bronchi and bronchioli, but there are seldom Lung mast cells around the pulmonary blood vessels and in the alveolar septa. The measurement of pulmonary arteries wall indicat that the media thickness percentage of the pulmonary arteriole of Tibetan Mastiff living at different elevations are no conspicuous different and they supper than yaks and llamas.The Ultrastruetural Study indicat that the wall of an alveoli are lined with the alveolar epithelium, which is composed of two specialized cells: simple squamous cells(typeâ… ) and cuboidal cells(typeâ…¡). Typeâ… cells make up most of the alveolar surfaces.These cells are thin and flat and the nucleus were ellipse. The nuclear part of typeâ… is thickess while the other parts are thinness. Slight organelles are grouped around the nucleus such as the Golgi complex, endoplasmic reticulum, and mitochondria. There are a great deal of microspike within internal surface of typeâ… which sometimes are incontinuous and the cytoplasm contains abundant pinocytotic vesicles. The typeâ…¡cell is large and there are many organelles and Lamellar bodies within intracytoplasm. They are interspersed among the typeâ… alveolar cells with which they have occluding junctions.The pulmonary air-blood barrier of Tibetan Mastiff is also composed of an epithelial layer, an interstitial layer and a layer of capillary endothelium. But in difference position the thickness of air-blood barrier is difference especially very thin between the non nuclear part of capillary endothelium and the non nuclear part of typeâ… pneumonocyte which composed of significant respiratory membrane. The basal lamina of respiratory membrane are homogen, the blood capillary are continuous and there are abundant pinocytotic vesicles have been found in endotheliocyte.