Hyperoxygenated Hydrogen-Rich Solution Suppresses Lung Injury Induced by Hemorrhagic Shock in Rats

Abstract:

Background: Hemorrhagic shock could induce acute lung injury (ALI), which is associated with cell hypoxia, lung tissue inflammation, free radical damage, and excessive cell apoptosis. Our previous studies demonstrated that hyperoxygenated solution could alleviate cell hypoxia. Furthermore, hydrogen-rich solution (HS) could relieve lung tissue inflammation, free radical damage and excessive cell apoptosis. Therefore we hypothesize that Hyperoxygenated Hydrogen-rich solution (HOHS) can protect the lung against ALI.

Materials and methods: SD rats were randomly divided into five groups (n = 6 at each time point in each group) and were exposed to Hemorrhagic shock induced ALI, and then treated with lactated Ringer's solution (LRS), hyperoxygenated solution, HS, and HOHS, respectively. The protective effects of these solutions were assessed using methods as follows: arterial blood samples were collected for blood gas analysis; Bronchoalveolar lavage fluid was collected for cell count and protein quantification; lung tissue samples were collected to measure wet/dry ratio, as well as levels of T-SOD, MDA, TNF-α, and IL-6; Caspase-3 and TUNEL-positive cells, and pathological changes were observed under light microscope; ALI was scored using the Smith scoring method; ultrastructural changes of lung tissues were further observed with transmission electron microscopy.

Results: The results indicated that PaO2, PaCO2, and T-SOD increased in the three treatment groups (P < 0.05), most significantly in the HOHS group (P < 0.01) compared with the LRS group; and conversely that the levels of lactate, MDA, TNF-α and IL-6, cell count, protein content, caspase-3 and TUNEL-positive cells as well as ALI score decreased in the three treatment groups (P < 0.05), most significantly in the HOHS group (P < 0.01) compared with the LRS group. Morphological observation with optical microscope and electron microscopy showed that compared with the LRS group, cell damage in the three treatment groups improved to a varying extent, especially evident in the HOHS group. Conclusions: These findings demonstrate that HOHS can protect the lung against ALI induced by hemorrhagic shock.