[Morpho-functional estimation of blood-air barrier and lung surfactant in rats of different age].

The alveolar-capillary barrier (or membrane, or blood-air barrier) exists in the gas exchanging region of the lungs. The investigation of the structural components of blood-air barrier under the influence of different factors in the organism at different age is one of the clinically significant problems of medicine. The influence of duration barocameral hypoxia on blood-air barrier of the mature and old age rats was studied. The significant changes of the blood-air barrier components both in ontogenesis and under hyperbaric hypoxia, especially in old age were revealed. Research proves the significant role of blood-air barrier factor on the age-associated involution of respiratory system (fibrosis, sclerosis). The most sensitive were cytoplasmatic processes of type I alveolocytes. Type II alveolocytes, basic membrane and elastic fibers in interstitial tissue were more stabile. The investigation showed that blood-air barrier directly reacts on environmental factors, decreasing the partial pressure of oxygen in the inspired air.