Protective effect of intermittent hypobaric hypoxia against radiation-induced liver damage in Sprague-Dawley rats

Abstract

BACKGROUND:

Without timely and effective interventions or treatments, radiation-induced liver damage (RILD) can lead to serious consequences for the patients and their families.

OBJECTIVE:

To investigate the protective effect of intermittent hypobaric hypoxia preconditioning (IHHP) in RILD.

METHODS:

Male adult SD rats were randomly divided into 8 groups including one control group, one only irradiation group and other experimental groups. Blood routine tests and liver function tests were all assessed with abdominal venous blood. Moreover, hematoxylin eosin (HE) staining and immunohistochemistry assay were used to detect the histopathological changes and expressions of transforming growth factor- $\beta$ 1 (TGF- $\beta$ 1), tumor necrosis factor $\alpha$ (TNF- $\alpha$ ) and hypoxia-inducible factor 1 $\alpha$ (HIF-1 $\alpha$ ) in radiated liver sections.

RESULTS:

Blood routing tests showed that RBC, WBC and Hb were all significantly increased while the differences of these results between different groups with same simulated altitude were approximate. However, liver function in the IHHP plus irradiation at 4000 m group was significantly decreased ( $P<$ 0.05) compared to only irradiation groups, and the manifestation of HE and lower positive expression of TNF- $\alpha$ showed improved histopathological changes in the liver section. Furthermore, no significant difference of HIF-1 $\alpha$ expression between any two groups treated with IHHP was observed.

CONCLUSION:

IHHP at the altitude of 4000 m group could alleviate the radioactive liver damage by downregulating TNF- $\alpha$ and less strong positive expression of TGF- $\beta$ 1. Furthermore, patients exposed to radiation might benefit from this treatment to prevent or reduce the RILD.