Effects Of Lipopolysaccharide On Alveolar Macrophages' Cytokines And Its' Apoptosis In Aged Rate

ObjectiveEstablish the aged rats model,collect the alveolar macrophages. To investigate the effects of lipopolysaccharide(LPS) on alveolar macrophages'cytokines and its'apoptosis in aged rats.MethodsFour-month-old Wistar rats were used as experimental animals. D-galactose 50mg.kg-1 was used to establish aged animal model. The rats were divided into 4 groups: aged model group,aged control group,adult group and adult control group.Each group contained 6 rats.The trachea bronthi and lungs were isolated and lavaged with normal saline.One minute later the bronchoalveolar lavage fluid (BALF) was reextracted.Cells were collected from the fluid and put into 6-wells cell culture plate.The alveolar macrophages (AMs) adhered to the wall were collected, suspended again cultured,re-collected, centrifuged and isolated. The AMs of aged model group and adult group were attacked by LPS 10 mg.1-1,24 hours later the cell culture supernatant was collected.TNF-αand ET-1 were determined by ELISA. Apoptosis of AMs were measured by flow cytometry.Results1.TNF-αand ET-1 of the aged and adult rats induced by LPS are higher than that of the control group.2.TNF-αof the aged rats induced by LPS is higher than that of the adult rats induced by LPS,and ET-1 is the same to TNF-α.The apoptic rate (APO) of AM in the aged rats stimulated by LPS was 50.57%±2.29%,significantly higher than that of the control rats(17.25%±1.68%,P<0.05).Compared with the aged,the adult rats stimulated by LPS(28.22%±1.75%) was higher than that of the control group(14.25%±3.09%, P<0.05). ConclusionsThese data suggest that alveolar macorphages play an important role in early LPS-induced lung injury.The aged rats are more sensitive to LPS than the adult rats.The AM APO% of aged rats stimulated by LPS is higher than that of the adult rats.