Interplay of Surfactant Protein A and Tumor Necrosis Factor α in Lung and Intestinal Tissues of Rats with Severe Pneumonia.

The evaluation of disease progression in rats with severe pneumonia and septic shock relies on the expression of indicators in the lung, intestinal microenvironment, and serum. A rat model was created for this purpose and the serum samples were collected at various stages. The levels of procalcitonin (PCT), C-reactive protein (CRP), surfactant protein A (SP-A), and tumor necrosis factor α (TNF-α) in the serum and SP-A in the alveolar lavage fluid were measured using enzyme-linked immunosorbent assay ELISA. Additionally, western blot was used to measure SP-A and TNF-α levels in lung and intestinal tissues. The results indicated that early in severe pneumonia, intestinal damage was less than lung damage, but it worsened over time. SP-A expression in intestinal tissue rose within 12 h post-modeling and matched lung tissue after 24 h, showing a declining trend. After modeling, the serum levels of SP-A and TNF-α were significantly higher than the control group. SP-A can indicate the health of the blood gas barriers and intestinal mucosal barriers. Tracking TNF-α and SP-A levels during severe pneumonia can offer precise data on disease progression and prognosis.