Renal proliferation and apoptosis against ascorbic acid administration in a model of acute radiation nephropathy

Abstract

BACKGROUND: Radiation exposure, an integral part of the treatment of malignant neoplasms, is associated with a risk of radiation nephropathy because of the high radiosensitivity of the kidneys. The analysis of renal tissue proliferation and apoptosis is important to understand the mechanisms of radiation damage and develop treatment strategies. AIM: To evaluate endothelial proliferation and apoptosis of vascular tubules and nephrocytes during preradiation administration of ascorbic acid in a model of radiation nephropathy. MATERIALS AND METHODS: Wistar rats (n=90) were divided into groups: I, control (n=15); II, irradiation, 2 Gy dose (n=15); III, irradiation, 8 Gy dose (n=15); IV, irradiation, 2 Gy dose + ascorbic acid, intraperitoneal injection at 50 mg/kg (n=15); V, irradiation, 8 Gy dose + ascorbic acid, intraperitoneal injection at 50 mg/kg (n=15); VI, ascorbic acid, intraperitoneal injection at 50 mg/kg (n=15). Kidney slides were stained with hematoxylin and eosin. In addition, immunohistochemical evaluation of the expression levels of Ki-67- and Cas-3-positive cells was performed. RESULTS: The histological study showed that preradiation administration of ascorbic acid (intraperitoneal injection of 50 mg/kg) in the acute radiation nephropathy model induced by local irradiation with electrons at 2 and 8 Gy contributed to the statistical reduction of pathomorphologic changes. According to the results of immunohistochemical evaluation of proliferation and apoptosis, distribution of Ki-67- and Cas-3-positive cells in the tubules, epitheliocytes of proximal and distal tubules of nephrons in mono-irradiation groups revealed the activation of the terminal stage of cell death, which correlated with the electron irradiation dose. Moreover, in the experimental groups with preirradiation administration of ascorbic acid, a significant decrease in the intensity of apoptosis was recorded. CONCLUSION: Preradiation administration of ascorbic acid reduces the strength of radiation-induced kidney damage and the effect of electron irradiation on the life cycle of tubular cells and epitheliocytes of nephron tubules while increasing the effectiveness of the antioxidant defense.