Hypoxia: A cause of acute renal failure and alteration of gastrointestinal microbial ecology

Abstract

Oxygen is very important to the existence of life. Oxygen deficiency, defined as hypoxia, elicits adaptive responses in cells and tissues. Lower oxygen concentration can cause the alteration of renal function, affects the maintenance of a balance of the body fluids, electrolytes, pH, and blood pressure homeostasis. Impaired fluid regulation could, in addition, contribute to the precipitation of pulmonary edema and exacerbate hypoxemia which may accelerate the progression of chronic kidney disease. In this context, the present study attempted to evaluate the association of renal injury and oxidative stress at different atmospheric pressures (1829, 3657, and 5486 m). Limited fecal analysis of experimental animals was also done to evaluate the impact of hypobaric hypoxia on the composition of dominant gastrointestinal microbiota. The study was performed on 24 male Wister strain rats and divided into four groups (C, HA-I, HA-II, and HA-III), and exposure was carried out for seven days period. In hypoxic exposure rats, plasma urea, creatinine, electrolytes and malonaldehyde level elevated and catalase and superoxide dismutase level diminished significantly compared to the controls. Increase in blood uremia profile, toxicity markers, and lipid peroxidation marker enzymes indicated that hypoxia causes renal failure. Histological structures of the kidney of group HA-II and HA-III animals showed severe disorganization of glomerulus and dilation of renal tubules. These results indicate nephrotoxicity or acute renal failure can occur at hypobaric hypoxia and it also affected the gut microbial population. This alteration was observed significantly above 3000 m.