Characterization of the Impacts of Living at High Altitude in Taif: Oxidative Stress Biomarker Alterations and Immunohistochemical Changes

Abstract

At high elevations, the human body experiences a number of pathological, physiological, and biochemical changes, all of which have adverse impacts on human health and organ vitality. This study aimed to investigate the alterations in the liver and kidney biomarkers, oxidative stress markers, gene expression, and cellular histology of rats maintained at high altitudes and normal sea level. A total of twenty male Wistar rats at 2 months of age were randomly assigned to two groups. The rats in group A were maintained at normal sea level in Jeddah, whereas rats in group B were maintained in an area in Taif 2600 m above sea level. After 2 months of housing, orbital blood samples were collected for the analysis of significant biochemical indicators of oxidative stress biomarkers of the liver and kidneys. Liver and kidney tissues from both groups were taken to examine the hepatorenal changes occurring at the biochemical, histological, immunohistochemical, and genetic levels. The results revealed substantial increases in the serum levels of liver and kidney biomarkers (GPT, GOT, urea, and creatinine) and decreases in the serum levels of antioxidant biomarkers (SOD, catalase, GSH, and NO). In parallel, the levels of the malondialdehyde (MDA) tissue damage marker and inflammatory cytokines (IL-1β, TNF-α, and IFN-γ) were increased in the high-altitude group compared to the normal sea level group. In addition, there were significant alterations in the oxidative and inflammatory status of rats that lived at high altitude, with considerable upregulation in the expression of hepatic VEGF, type 1 collagen, Cox-2, TNF-α, and iNOS as well as renal EPASI, CMYC, HIF-α, and EGLN-2 genes in the high-altitude group compared with controls housed at normal sea level. In conclusion, living at high altitude induces hepatorenal damage and biochemical and molecular alterations, all of which may serve as critical factors that must be taken into account for organisms living at high altitudes.

Keywords

• high altitude
• normal sea level
• oxidative stress
• hepatorenal dysfunction
• gene expression
• Taif