Pan Yang1, Xingmin Qu2, Senrong Qi3, Gang Li4, Songlin Wang5. 1. Salivary Gland Disease Center and Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, School of Stomatology, Beijing Laboratory of Oral Health, Capital Medical University, Beijing, 100050, China. 2. Department of Pediatric Dentistry, School of Stomatology, Capital Medical University, Beijing, 100050, China. 3. Department of Oral and Maxillofacial Radiology, School of Stomatology, Capital Medical University, Beijing, 100050, China. 4. Department of Oral and Maxillofacial Radiology, Peking University School and Hospital of Stomatology, Beijing, 100081, China. 5. Salivary Gland Disease Center and Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, School of Stomatology, Beijing Laboratory of Oral Health, Capital Medical University, Beijing, 100050, China. Electronic address: slwang@ccmu.edu.cn.
Abstract
OBJECTIVES: To explore whether the inorganic nitrate has a protective effect on biological damage induced by cone-beam computed tomography (CBCT) and compare it with Vitamin C. MATERIALS AND METHODS: Sixty Wistar rats were randomly separated into 6 groups: control group, irradiation (IR) group, NaNO3 group, IR + NaNO3 group, Vitamin C group, and IR + Vitamin C group. Rats were whole-body irradiated with CBCT four times. The absorbed dose of the skin surface was measured using thermoluminescent dosemeter chips and the mean whole-body absorbed dose was calculated. Peripheral blood was collected at 0.5 h and 24 h after irradiation. Bodyweight and organ index of rats before and after irradiation were analyzed. The bone marrow was taken for micronucleus test. Lymphocytes were isolated from peripheral blood for γ-H2AX immunofluorescence assay, apoptosis and reactive oxygen species (ROS) analysis. Total antioxidant capacity (TAC), malondialdehyde (MDA) and superoxide dismutase (SOD) in serum were detected. RESULTS: The mean absorbed dose of four whole-body CBCT scans for rats was 73.04 mGy. Bodyweight and organ index before and after irradiation with X-ray had no significant differences. The micronuclei frequency of IR + NaNO3 and IR + Vitamin C groups showed a significant decrease than that in the IR group, which was not significantly different from that of the control group. The γ-H2AX foci rates in the IR + NaNO3 group and the IR + Vitamin C group were significantly lower than that in the IR group. In addition, the foci rate of the IR + NaNO3 group returned to the baseline level of the control group 24 h after CBCT scanning. The apoptosis of lymphocytes in rats did not increase. The IR + NaNO3 group (P < 0.001) or IR + Vitamin C group (P < 0.001) showed a significant increase in ROS positive cells rate with the control group, while were significantly lower than those in the IR group (P < 0.01). In addition, the ROS-positive cell rate in the IR + NaNO3 group was significantly lower than that in the IR + Vitamin C group. The MDA in the serum of rats increased significantly, while SOD and TAC decreased significantly at 0.5 h after irradiation. CONCLUSIONS: Compared with Vitamin C, inorganic nitrate had better preventive effects on biological damage induced by CBCT scans in rats.
OBJECTIVES: To explore whether the inorganic nitrate has a protective effect on biological damage induced by cone-beam computed tomography (CBCT) and compare it with Vitamin C. MATERIALS AND METHODS: Sixty Wistar rats were randomly separated into 6 groups: control group, irradiation (IR) group, NaNO3 group, IR + NaNO3 group, Vitamin C group, and IR + Vitamin C group. Rats were whole-body irradiated with CBCT four times. The absorbed dose of the skin surface was measured using thermoluminescent dosemeter chips and the mean whole-body absorbed dose was calculated. Peripheral blood was collected at 0.5 h and 24 h after irradiation. Bodyweight and organ index of rats before and after irradiation were analyzed. The bone marrow was taken for micronucleus test. Lymphocytes were isolated from peripheral blood for γ-H2AX immunofluorescence assay, apoptosis and reactive oxygen species (ROS) analysis. Total antioxidant capacity (TAC), malondialdehyde (MDA) and superoxide dismutase (SOD) in serum were detected. RESULTS: The mean absorbed dose of four whole-body CBCT scans for rats was 73.04 mGy. Bodyweight and organ index before and after irradiation with X-ray had no significant differences. The micronuclei frequency of IR + NaNO3 and IR + Vitamin C groups showed a significant decrease than that in the IR group, which was not significantly different from that of the control group. The γ-H2AX foci rates in the IR + NaNO3 group and the IR + Vitamin C group were significantly lower than that in the IR group. In addition, the foci rate of the IR + NaNO3 group returned to the baseline level of the control group 24 h after CBCT scanning. The apoptosis of lymphocytes in rats did not increase. The IR + NaNO3 group (P < 0.001) or IR + Vitamin C group (P < 0.001) showed a significant increase in ROS positive cells rate with the control group, while were significantly lower than those in the IR group (P < 0.01). In addition, the ROS-positive cell rate in the IR + NaNO3 group was significantly lower than that in the IR + Vitamin C group. The MDA in the serum of rats increased significantly, while SOD and TAC decreased significantly at 0.5 h after irradiation. CONCLUSIONS: Compared with Vitamin C, inorganic nitrate had better preventive effects on biological damage induced by CBCT scans in rats.