BACKGROUNDIrradiation dose and volume are the major physical factors of radiation-induced lung injury. The study investigated the relationships between the irradiation dose and volume in radiation-induced lung injury by setting up a model of graded volume irradiation of the rat lung.

METHODSAnimals were randomly assigned to three groups. The ELEKTA precise 2.03 treatment plan system was applied to calculate the irradiation dose and volume. The treatment plan for the three groups was: group 1 received a "high dose to a small volume" (25% volume group) with the mean irradiation volume being 1.748 cm(3) (25% lung volume); the total dose and mean lung dose (MLD) were 4610 cGy and 2006 cGy, respectively (bilateral AP-PA fields, source to axis distance (SAD) = 100 cm, 6MVX, single irradiation); Group 2 received a "low dose to a large volume" (100% volume group) with the mean irradiation volume being 6.99 cm(3) (100% lung volume); the total dose was 1153 cGy. MLD was 2006 cGy, which was the same as that of group 1 (bilateral AP-PA fields, SAD = 100 cm, 6MVX, single irradiation); Group 3 was a control group. With the exception of receiving no irradiation, group 3 had rest steps that were the same as those of the experimental groups. After irradiation, functional, histopathological, and CT changes were compared every two weeks till the 16th week.

RESULTSFunctionally, after irradiation breath rate (BR) increases were observed in both group 1 and group 2, especially during the period of 6th - 8th weeks. The changes of BR in the 100% volume group were earlier and faster. For the 25% volume group, although pathology was more severe, hardly any obvious increase in BR was observed. Radiographic changes were observed during the early period (the 4th week) and the most obvious changes manifested during the mediated period (the 8th week). The extensiveness of high density and the decreased lung permeability were presented in the 100% volume group, and ground glass opacity and patchy consolidation were presented in the 25% volume group without pleural effusion, pleural thickening, and lung shrinking. Morphologically, the 100% volume group mainly presented signs of vascular damage, including signs of vascular wall edemas, hypertrophy, and sclerosis. The 25% volume group mainly presented with erythrocyte cell exudation, inflammation, and parenchymal damage.

CONCLUSIONSThe delivery of a small dose of radiation to a large volume is not safe. A low dose smeared out over large volumes, albeit reversible, may lead to fatal respiratory dysfunction. Damage to the lung may be more dependent on the volume of irradiation than on the radiation dose. Clinically, the safest approach is to limit both the volume of the irradiated normal lung and the amount of received radiation.

Animals ; Dose-Response Relationship, Radiation ; Lung ; radiation effects ; Lung Injury ; etiology ; Radiation Injuries, Experimental ; Rats ; Rats, Wistar

OBJECTIVETo observe the morphological changes and the regenerating ability of the fungiform papillae and taste buds after 60Co radiation with clinical doses in rats.

METHODSThe heads, faces and necks of 30 SD rats were radiated with a large dose and one time of 60Co in the clinical radiation. The general living condition and the number and shape of the fungiform papillae and taste buds of the tongues were observed after the radiation in rats.

RESULTSIn the group of 60Co radiation, the animals had wilting, decreasing appetite, losing weight. The heads, faces and necks of animals appeared redness, peeling of hair, increasing of secretions in 5 days after the 60Co radiation. The changes reached the summit in 10 days and the general living condition of the animals recovered in 60 days. The fungiform papillae and taste buds of the animals appeared degeneration, atrophy and collapsing in 5 days after the 60Co radiation. The injuries reached the summit in 10-20 days and the fungiform papillae and taste buds regenerated partially, and the some atrophied fungiform papillae and taste buds were not regenerated in 60 days.

CONCLUSIONThe damage to fungiform papillae and taste buds of tongue following the 60Co radiation with the clinical doses was very serious. The damaged fungiform papillae and taste buds can regenerate partially, but not completely.

Animals ; Radiation Injuries, Experimental ; pathology ; Rats ; Rats, Sprague-Dawley ; Regeneration ; Taste Buds ; pathology ; radiation effects ; Tongue ; pathology ; radiation effects

OBJECTIVETo investigate the ultrastructural variation of the facial nerve of rabbit with different dosage of (125)I seed brachytherapy.

METHODSFifty-four big ear rabbits were divided into 3 groups randomly and given 40 Gy, 80 Gy, 120 Gy respectively. Radioactive seeds were implanted in one side of parotid gland, the other side was implanted with vacant shell as a control group. The facial nerves were obtained 2, 4, 6 months respectively after operation and the histological ultrastructural changes observed by electromicroscope.

RESULTSIn the control group, epineurium was continuous, there was slight pitting edema under the epineurium, and axonal myelin was loose. In the test groups, there was slight pitting edema under the epineurium, and axonal myelin sheath was loose at 4th month. Macrophage and regenerated fibers were found in the 80 Gy group and myelin sheath lamellar separation, regeneration of nerve in the 120 Gy dosage. The myelin sheath lamellar was separated and axonal myelin loose in the test group at 6th month. Myelin sheath amellar separation and edema under the epineurium were found in the group of 80 Gy and 120 Gy.

CONCLUSIONSThe ultrastructure of the facial nerve is damaged by the dosage of 40 Gy, 80 Gy brachytherapy with (125)I seeds. The higher dosage the nerve receives, the more serious the damage will be. Both of the epineurium and axonal myelin sheath are integral and continuous 6 months after operation with dosage of 120 Gy.

Animals ; Brachytherapy ; Dose-Response Relationship, Radiation ; Facial Nerve ; radiation effects ; ultrastructure ; Female ; Iodine Radioisotopes ; administration & dosage ; radiation effects ; Male ; Rabbits ; Radiation Injuries, Experimental ; pathology ; Random Allocation

OBJECTIVETo study the effect of radiation injury on nitric oxide (NO) concentration in mouse peripheral blood and liver.

METHODSNIH mice were subjected to gamma-ray exposure at 9.0 Gy and transferred immediately in room temperature condition. NO concentrations in the liver and peripheral blood were examined before and at different time points after the exposure.

RESULTSCompared to that before exposure, NO concentration in the peripheral blood and liver significantly increased after gamma-ray exposure. NO concentration in the peripheral blood began to increase 3 h after the exposure, but that in the liver increased till 6 h after the exposure.

CONCLUSIONRadiation can cause the increase of NO concentration in the peripheral blood and liver, but different tissues may exhibit different response intensities to radiation.

Animals ; Gamma Rays ; Liver ; metabolism ; radiation effects ; Male ; Mice ; Nitric Oxide ; blood ; metabolism ; Radiation Injuries, Experimental ; blood ; metabolism ; Time Factors

OBJECTIVE: To observe histopathologic changes of irradiated guinea pigs' nasal mucosa treated with intranasal corticosteroids and to study the radioprotective effect of intranasal corticosteroids. METHOD: Fifty health guinea pigs nasal parts were performed irradiation by the WDVE-6MeV linear accelerator. They had accepted 5 Gy one time per week for three weeks through X-ray irradiating to establish the animal irradiation injury model. After that, they were divided into 2 groups randomly: the control group and the administration group and each group had 25 guinea pigs. The administration group received intranasal corticosteroids on the second day after three weeks irradiation, 5 animals per one group were sacrificed randomly at 1 W, 1 M, 2 M, 3 M, 4 M after administration, the histopathologic changes were observed under optical, scanning electron and transmission electron microscope respectively. RESULT: Using intranasal corticosteroids after irradiation, the early inflammatory reaction of the administration group was milder than the control group. With the drug being given constantly, the recovery of epithelial cell with irradiated damage was accelerated and the coverage rate of cilia went up obviously; After four months, the coverage rate of cilia had risen to 72.9%; But, for the control group, the coverage rate of cilia is only 50.2%. The atrophy of submucosal glandular organ was lessened and they displayed some extent secretory function. The reparation was accelerated as time went by. CONCLUSION Irradiation brought about serious injury on guinea pigs' nasal mucosa. But, the injury was lessen after using intranasal corticosteroids. Intranasal corticosteroids play the role of radioprotection for the irradiated nasal mucosa.
Adrenal Cortex Hormones ; pharmacology ; Animals ; Guinea Pigs ; Nasal Mucosa ; drug effects ; pathology ; radiation effects ; Radiation Injuries, Experimental ; prevention & control

OBJECTIVETo investigate the role of nasal mucosa fibrosis on radiation induced nasal mucosa injury.

METHODSSeventy two male rats were randomly divided into two groups, control group and irradiation injured group (radiation dose were 40 Gy); the rats were killed 1 week, 2 weeks, 4 weeks, 8 weeks, 3 months and 6 months after the finish of radiation. The middle turbinates of the animals were removed. The pathological change of the nasal mucosa were observed with scanning electron microscope, transmission electron microscope, hematoxylin and eosin (HE), alcian blue-periodic acid-Schif (AB-PAS), and Masson Trichrome (MT). The Hyp content in nasal mucosa was measured with chemo-chromatometry.

RESULTSAfter radiation, the pathological characteristics in early stage (within 4 weeks) was acute inflammatory reaction. The repair of nasal mucosa started 4 weeks after radiation, lasted to 6 months. The deposition of collagen in nasal mucosa could be found 1 week after irradiation and increased gradually.

CONCLUSIONIrradiation could induce a serials of pathological changes on nasal mucosa. The nasal mucosa fibrosis may be one of the reasons of persistent irradiation induced nasal mucosa injury.

Animals ; Fibrosis ; Male ; Nasal Mucosa ; pathology ; Radiation Injuries, Experimental ; pathology ; Rats ; Rats, Sprague-Dawley ; Wound Healing

OBJECTIVETo assess the radioactive damage induced by interstitial 125I seed implantation to the rabbit urethra.

METHODSWe implanted 24 rabbits with 125I seeds 1.0 cm to the urethra at the radiation dose of 14.8 MBq (Group A), 29.6 MBq (Group B) and 44.4 MBq (Group C), while a non-radioactive seed was implanted near the urethra of the controls (Group D). Four weeks later, we detected the radiation-induced pathological and morphological changes in the urethra by H&E, light microscopy and electron microscopy.

RESULTSFour weeks after the implantation, no obvious histopathological and ultrastructural changes were observed in the urethral tissues of the experimental rabbits as compared with the control group. The scores on the radioactive damages to the urethra obtained by light microscopy were (2.20 +/- 0.18), (2.23 +/- 0.15), (2.27 +/- 0.10) and (2.10 +/- 0.17) respectively in Group A, B, C and D, with no significant differences between the first three groups and the control (P > 0.05). And the scores on the FlaMeng semi- quantitative analysis of mitochondria in the experimental groups were (1.23 +/- 0.13), (1.34 +/- 0.25) and (1.41 +/- 0.30) respectively, not significantly different from (1.12 +/- 0.13) the control (P > 0. 05).

CONCLUSIONThe radioactive damage induced by 125I seeds to the urethra increases with the enhanced radiation dose. Intraoperative implantation of 125I seeds at the prescription dose has no obvious adverse effect on the rabbit urethra.

Animals ; Dose-Response Relationship, Radiation ; Iodine Radioisotopes ; adverse effects ; Male ; Microscopy, Electron ; Rabbits ; Radiation Injuries, Experimental ; etiology ; pathology ; Urethra ; pathology ; radiation effects ; ultrastructure

OBJECTIVETo investigate the effect of Inonotus obliquus polysaccharides on testicular injury induced by exposure to high power microwave (HPM) in rats.

METHODSA total of 30 male Wistar rats were randomly divided into 5 groups, i.e., the normal control group, the microwave radiation model group, the treatment group, the new microwave radiation model group, and the prevention group, 6 in each group. All rats, except those in the normal control group, were exposed to microwave at an average power density of 200 mW/cm2 for 6 min. Rats in the control group and the model group were administered with normal saline by gastrogavage, once a day. Rats in the treatment group and the prevention group were given with Inonotus obliquus polysaccharides by gastrogavage, 2 mL each time (400 mg/kg body weight), once a day. All rats were sacrificed on the 11th day.The sperm density and the rate of sperm deformity were determined. Pathological changes of testis were observed by light microscope and transmission electron microscope.

RESULTSShort-term HPM irradiation could significantly reduce the sperm density and increase the sperm deformity rate (P < 0.05). Meanwhile, obvious pathological changes of testes occurred. Compared with the two model groups, the sperm density increased and the sperm deformity rate decreased in the treatment group and the prevention group (P < 0.05). Under the light microscope, injuries of spermatogenic cells and stromal cells, as well as vascular dilatation and congestion were obviously alleviated in the treatment group and the prevention group. Mitochondrial swelling and endoplasmic reticulum expansion shown by ultrastructural observation were also significantly alleviated. Of them, injuries of spermatogenic cells and inflammation response were milder in the treatment group than in the prevention group.

CONCLUSIONSInonotus obliquus polysaccharides had significant protective effect on microwave radiation induced testicular injury. Better effect was obtained by therapeutic medication than preventive medication.

Animals ; Basidiomycota ; chemistry ; Male ; Microwaves ; adverse effects ; Polysaccharides ; pharmacology ; Radiation Injuries, Experimental ; prevention & control ; Radiation-Protective Agents ; pharmacology ; Rats ; Rats, Wistar ; Testis ; drug effects ; pathology ; radiation effects

Wound combined with total body irradiation (TBI) injury results in impairment of tissue repair and delayed processes of healing, so it has been considered as an important and representative model of impaired wound healing, but the mechanism is not fully clarified. Fibroblasts in wound are the most important cells participating in tissue repair, whereas its radiosensitivity is not high. To understand whether TBI injury has direct damaging effects on fibroblasts in wound, fibroblasts in wound combined with TBI injury and in wound of simple incision injury were isolated and cultured, and parameters associated with tissue repair were determined. The results showed that the abilities of proliferation, attachment and adhesion of fibroblasts isolated from wounds combined with TBI injury significantly decreased as compared with those of simple incision injury, nevertheless, apoptotic ratio of fibroblasts isolated from wounds combined with TBI injury increased significantly. These data suggest that TBI injury may cause direct damaging effects on fibroblasts in wounds, which might be one of the dominant reasons for impairment of wound healing when it is combined with TBI injury.
Animals ; Disease Models, Animal ; Fibroblasts ; metabolism ; physiology ; radiation effects ; Radiation Injuries, Experimental ; metabolism ; Rats ; Rats, Wistar ; Skin ; injuries ; Whole-Body Irradiation ; Wound Healing ; physiology

OBJECTIVETo investigate the effects of Morina Officinalis How (MOH) on the abnormal levels of serum luteotrophic hormone (LH) and LH receptor (LHR) in the testis tissue induced by cellphone radiation (CPR) in rats.

METHODSFifty adult male SD rats were randomly divided into five groups of equal number: sham CPR, untreated CPR, negative double distilled water (DDW) control, aqueous MOH extract, and alcohol MOH extract. All the animals were exposed to mobile phone radiation except those of the sham CPR group. Then, the rats of the latter two groups were treated intragastrically with MOH at 20 g per kg of the body weight per day in water and alcohol, respectively. After 2. weeks of treatment, all the rats were sacrificed for measurement of the levels of serum LH and LHR in the testis tissue.

RESULTSThe levels of serum LH and LHR were 30.15 ± 8.71 and 33.28 ± 6.61 in the aqueous MOH group and 0.96 ± 0.06 and 0.94 ± 0.08 in the alcohol MOH group, both significantly decreased as compared with the negative DDW controls (P < 0.05), but with no remarkable difference between the two MOH groups (P > 0.05).

CONCLUSIONMOH can improve CPR-induced abnormality of LH and LHR in adult male rats.

Animals ; Cell Phone ; Electromagnetic Radiation ; Luteinizing Hormone ; blood ; drug effects ; radiation effects ; Male ; Morinda ; chemistry ; Radiation Injuries, Experimental ; blood ; drug therapy ; Random Allocation ; Rats ; Receptors, LH ; blood ; drug effects ; radiation effects ; Testis ; radiation effects