[The ultrastructural changes in type-2 pneumocytes in experimental heat and endotoxic shock].

The early ultrastructural changes in type 2 pneumocytes (PN2) as a result of burn and endotoxic shock in rats and rabbits were studied. Stereotype morphological damages in PN2 were established. Differences between experimental models were quantitative and depend mainly from the severity of shock and animals species. Morphofunctional heterogenity of PN2 population leads to the appearance of three groups of PN2: 1) PN2 with degenerative changes; 2) PN2 with "stress" hyperactivity and exocytosis of lamelar bodies; and 3) PN2 with increased number of lamelar bodies. Disturbances of lamelar bodies morphogenesis (conglomerates, giant lamelar bodies) as well as lamelar bodies formation by alternative way - directly from rough endoplasmic reticulum were observed. The predominant part of the described PN2 lesins were adaptive in character.