| OBJECTIVE:To study the effects of different dosages of X-ray on lung of developing filial mice, antioxide enzymes activity , the structure and inter related polypeptides after irradiation were determined, which is to explore the synthetical effect on lung of developing filial mice,provide a basis for developmental biology,clinical cure of irradiation damnification and prevention of irradiation.METHODS:Age of 5-7 days filial mice were choosed and divided into six groups(32 per group).The six groups irradiated by different dosages(0.0,0.5,2.0,3.5,5.0,6.5 Gy) X-rays respective every day and persisted three days. Eight filial mice of every group were killed (1,5,10,20 d) after irradiation, and effect on the activities of Superoxide dismutase(SOD),Glutathione Peroxidase (GSH-Px),and the contents of Maleic dialdehyde (MDA) , Reduced Glutathione Hormone (GSH) in lung were determined after this tissue be skived from this filial mice and confect to liquid supernatant. Changes of histological structure were observed by histological methods and thickness of Alveolar Septa and diameter of Alveolous were measured. Expressions of Bax and KGF in lung of filial mice were observed by immunohistochemistry method. The expression intensity of them was measuring by Stereological method and image analysis.RESULT:1. X-ray affects the SOD activity in lung of filial mice at their growing periods. After the radiation of 0.5Gy and 2.0Gy X-ray, SOD activity in lung of filial mice is higher than the control group with apparent or extremely apparent differences (P<0.05 or P<0.01). Early stages it increases gradually, later decreasing and then increasing and all of which are lower than the control groups with apparent or extremely apparent difference(P<0.05 or P<0.01).2. X-ray affects the MDA content in lung of filial mice in their growing periods. After the radiation of 0.5Gy and 2.0Gy X-ray, content of MDA in lung of filial mice is lower than the control group with apparent or extremely apparent differences (P<0.05 or P<0.01). Those were being radiated by 0.5Gy and 2.0Gy X-ray, MDA content in their lungs decreases and approximately equal to the normal level in early stages, later increases and even reach the normal level later. After the radiation of 3.5Gy, 5.0Gy and 6.5Gy, MDA content in the lung tissue of filial mice increases at first and then decreases later after that, and all of which are above that of the control groups with apparent or extremely apparent differences(P<0.05 or P<0.01).3. X-ray affects GSH-Px activity in lung of the filial mice during their growing periods. After 1-20d by 0.5Gy X-ray radiation, GSH-Px activity in the lung of filial mice is higher than the control group with extremely apparent or apparent differences(P<0.01or P<0.05), and the activity decreases as the time passing by. With the X-ray radiation of 2.0,3.5,5.0 and 6.5Gy, GSH-Px activity in lung of filial mice is lower than that of the control group with apparent or extremely apparent differences (P<0.05 or P<0.01) and has the tendency of decreasing-to-increasing.4. X-ray affects the GSH content in lung of filial mice during their growing periods. After the radiation of 0.5Gy X-ray after early stages, GSH content in lung of filial mice is higher than the control group with extremely apparent differences(P<0.01). Later, GSH content in lung of filial mice decreases even reaches to that of the control group with unapparent or apparent differences(P>0.05 or P<0.05). With the X-ray radiation of 2.0,3.5,5.0 and 6.5Gy, GSH content in the lung of filial mice is lower than the control group with apparent and extremely apparent differences (P<0.05 or P<0.01).5. X-ray affects the histological structure in lung of filial mice. X-ray radiation affects the diameter of Alveolar and the thickness of Alveolar Septa for different degrees in filial mice. After being radiated by 0.5 Gy and 2.0 Gy X-ray radiation, the interstitial cells in the lung of filial mice are in high density, the diameter of Alveolar and the thickness of Alveolar Septa decrease by different degrees. The diameter of Alveolar and the thickness Alveolar Septa of the 3.5Gy, 5.0Gy and 6.5Gy groups increase with various degrees compared with that of the control group.6. X-ray affects the expression of Bax protein in lung of filial mice. There Bax protein immunoreaction appeared in lung of filial mice, and the intensity of the immunoreaction was increased with augmentation of dosages, but decreased gradually, and recovered to nearly normal levels over time. 7. X-ray affects the expression of KGF in lung of filial mice. There KGF immunoreaction appeared in lung of filial mice, and the intensity of the immunoreaction was increased with augmentation of dosages. It increased in the beginning and then decreased, but increased later, and come back to normal level finally.CONCULSION:1. X-ray affects the activity of antioxidase in lung of filial mice remarkably.After the radiation of low doses, SOD activity in lung of filial mice increases gradually in early stages, later decreasing. MDA content in lung of filial mice decreases gradually in early stages, later increasing. After the radiation of high doses, it is contradictory. After the radiation of low doses, GSH-Px activity and GSH content in lung of filial mice is higher than the control group in early stages and that is lower than the control group later, all that decreases gradually over time. 2. X-ray affects the histological structure in lung of filial mice. X-ray radiation affects the diameter of Alveolar and the thickness of Alveolar Septa for different degrees in filial mice. After the radiation of low doses, the interstitial cells in the lung of filial mice are in high density, the diameter of Alveolar and the thickness of Alveolar Septa decrease by different degrees. The diameter of Alveolar and the thickness Alveolar Septa of the high doses groups increase with various degrees compared with that of the control group.3. X-ray affects the expression of Bax and KGF protein in lung of filial mice. The intensity of the immunoreaction was increased with augmentation of dosages, its induction of injury and repair of cell has increased. Specifically as follows: after radiation in the early stages, the expression of Bax and KGF protein had strong positive distribution in lung of filial mice, but the expression of Bax decreased gradually, and recovered to nearly normal levels over time. And the expression of KGF increased in the early stages and decreased gradually, but later recovered to nearly normal levels over time.High-doses of ionizing radiation can produce a large number of superoxide anion radicals in the organic body, resulting in oxidative damages in cells of the body tissue. While low -doses of ionizing radiation can induce immune excitation. Radiation can also activate the functions of various immune cells of the body, especially for the activation and differentiation of T-cell, which resulting in aerobic metabolism prosperity and the production of superoxide anion radicals even higher than the static state. So the activities of antioxidant-enzyme in tissue of the filial mice increased and content of lipid decreased after the low dosage X-ray. Free radical which produce by large dosage X-ray and could not be eliminate timely will assault cell and cause damage to tissue and activities of antioxidant-enzyme decreased. Histological structure of lung of the filial mice obviously changed after large dosage irradiation. Radiation can increase expression of Bax and KGF in lung of filial mice. There was a trend that the activity of target enzyme, expression of Bax and KGF and histological structure recovered slowly to the normal level after irradiation. The irradiation of X-rays affects the activity of target enzyme, expression of Bax and KGF and histological structure of developing filial mice significantly. In short, large dosages of irradiation would cause disadvantageous effect on developing filial mice,but the organism also have enginery to resist the radiation. |
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