Morphological and Molecular Biological Features of the Systemic Inflammatory Response in Old Wistar Rats with High and Low Resistance to Hypoxia.

Morphological and molecular biological features of LPS-induced systemic inflammatory response were assessed in old male Wistar rats with high (HR) and low (LR) resistance to hypoxia. The systemic inflammatory response was modeled by intraperitoneal injection of E. coli O26:B6 LPS; the animals were sacrificed after 6 h. In histological sections, the number of neutrophils in the interalveolar septa and the area of necrosis in the liver were determined. The expression levels of Hif1a, Hif2a, Nfkb, Vegf, Il1b, Il6, Il10, and Tgfb mRNA in the liver and serum concentrations of HIF-1α and IL-1β were determined. In 4-6 h after LPS injection, 3 (43%) of 7 HR rats died, whereas no deaths were observed among LR rats. At 6 h after LPS injection, the number of neutrophils in the interalveolar septa of the lungs in LR rats was significantly higher than in HR rats, while the area of necrosis in the liver did not differ. At the same time, the mRNA expression levels of the proinflammatory cytokine genes Il1b and Il6 increased in the liver of both HR and LR rats, whereas the expression of Il10 increased only in HR rats. The expression of the Hif1a gene in the liver was higher in LR rats, but the content of HIF-1α protein in blood serum was higher in HR animals. These data should be taken into account when developing new approaches to the therapy of systemic inflammatory response in infectious and inflammatory diseases in the elderly.