Influence Of Whole-body Irradiation Research Articles

Whole Body Irradiation Induces Cutaneous Dendritic Cells Depletion via NF-κB Activation

Background: Effect of ionizing radiation on cutaneous dendritic cells (cDC) is critical to its influence on immune status of the skin, which plays an important role in the progression and recovery of radiation skin sickness. This study was to study the influence of whole body irradiation (WBI) on the cDC. Methods: Density of epidermal and dermal DC was determined with a fluorescent microscopy and the DC numbers in lymph node were measured by flow cytometry. A FITC induced migration assay was also used to study the migration of DC. The expressions of cytokines and chemokines were evaluated by Realtime PCR, and the protein level of was measured by Western blot. Results: WBI caused depletion of cDC in epidermal as well as dermal and augmented FITC-induced migration of DC to the draining lymph node (LN). The number of DC migrated from ear explants to the CCL19-containing medium also increased after exposure to WBI. It was also found that WBI increased mRNA level of CCL19/CCL21 as well as CCR7 in LN and skin tissue. The expressions of TNFa, IL-1a, IL-1ß, and IL-6 in skin tissues were also greatly induced by WBI in a dose dependent manner. Finally, we found that WBI induced translocation of nuclear factor κB (NF-κB) and that the radiation-induced migration of DC was blocked by NF-κB inhibitor or TLR4 knockout. Conclusion: WBI caused cDC depletion through induction of DC migration to the draining LN, which might result from the activation of NF-κB and the induction of inflammatory microenvironment within the skin.

The influence of irradiation on the potential chondroprotective effect of aqueous extract of propolis in rats

Purpose: Cartilage degradation usually results as a consequence of inflammatory processes in the joints. To study this phenomenon experimentally, adjuvant-induced arthritis (AIA) was used as a model of chronic inflammation under the influence of irradiation. The potential chondroprotective effect of 13% aqueous extract of propolis (AEP) in arthritic rats was investigated.Materials and methods: The influence of whole body irradiation on the arthritic inflammatory response was investigated by subjecting rats to a Gamma source before the induction of arthritis. 13% AEP was injected intraperitoneally in a dose of 5 ml/kg and diclofenac was used as reference non-steroidal anti-inflammatory drug (NSAID) in a dose of 3 mg/kg. The chosen parameters for cartilage integrity were glycosaminoglycan (GAG), hydroxyproline contents in cartilage and cartilage oligomeric matrix protein (COMP) in serum. The serum levels of tumour necrosis factor-alpha (TNF-α), nitric oxide (NO) and the oxidative stress biomarkers such as blood glutathione (GSH) and plasma malondialdehyde (MDA) levels.Results: Induction of arthritis led to a reduction in GAG and hydroxyproline content of femoral cartilage and a corresponding rise in COMP in serum. Previous exposure to irradiation resulted in a milder reduction of GAG and hydroxyproline and a lesser rise in COMP. Treatment of arthritic irradiated and non-irradiated rats with 13% AEP markedly prevented the breakdown of cartilage in a much more effective manner than diclofenac. Both AEP and diclofenac were equipotent in reducing the level of TNF-α and were able to normalize NO and the oxidative stress biomarkers in non-irradiated and irradiated arthritic rats.Conclusion: The ability of propolis to protect cartilage degradation could therefore prove of value in the treatment of chronic arthritic diseases, offering an advantage over some NSAID, particularly those with a potential detrimental effect on cartilage integrity.

Early biological effects of whole body irradiation on rat lungs.

The influence of whole-body irradiation (WBI) with 4, 8 and 15 Gy ionizing radiation upon some biochemical indices in the bronchoalveolar lavage fluid (BALF) of rat lungs was studied. It was established that lactate dehydrogenase (LDH), alkaline phosphatase, (APH) and acid phosphatase (AcPH) activities show a dose-dependent decrease on the day 1 and day 5 after the irradiation. A similar trend was observed in the total protein content on the day 1. Angiotensin converting enzyme (ACE) activity was increased on the day 1 in the groups irradiated with 8 Gy and 15 Gy in comparison with the controls (190,2% and 187,5%, respectively). It was concluded that WBI decreases LDH, APH and AcPH levels in the lung cells, which secrete them into bronchoalveolar spaces. An irradiation with 8 Gy and 15 Gy WBI provokes an early damage on cytoplasmic membranes of the endothelial cells in lung capillars. It was considered that the bronchoalveolar lavage can find a more wide application for evaluation of the biological effect of ionizing radiation in lungs.

Influence of whole body irradiation and local shielding on matrix-induced endochondral bone differentiation

Subcutaneous implantation of demineralized bone matrix into allogeneic rats induces endochondral bone formation. We have investigated the effects of irradiation on the sequelae of the interaction of collagenous matrix and mesenchymal cells and on cartilage and bone differentiation. Rats were irradiated in a vertical direction with a midline dose of 850 rad. Radiation entered the rats ventrally while a small area of the upper thorax was locally shielded. After irradiation, bone matrix was implanted in shielded and nonshielded sites, and the implants were studied at various stages. On day 3, [3H]thymidine incorporation, an index of cell proliferation, was inhibited by 70% in the nonshielded sites compared to nonirradiated control rats. The degree of inhibition (35%) was less pronounced in shielded sites. Furthermore, there was recovery of cell proliferation in the shielded sites as opposed to the nonshielded contralateral site. A similar pattern was observed on day 7 as assessed by 35SO4 incorporation into proteoglycans during chondrogenesis. Bone formation and mineralization were quantified on day 11 by alkaline phosphatase activity and 45Ca incorporation. In nonshielded sites, there was a 73% inhibition of alkaline phosphatase activity. In conclusion, radiation impaired progenitor cell proliferation which resulted in decreased cartilage and bone differentiation. These findings imply that local mesenchymal cells proliferate and differentiate into bone in response to implanted collagenous matrix.

Studies on chemical protectors against radiation. XIX. Influence of whole body irradiation by soft X-ray on mouse skin (author's transl)

Studies on chemical protectors against radiation. XIX. Influence of whole body irradiation by soft X-ray on mouse skin (author's transl)

Influence of whole body irradiation on bcg contact suppression of a rat sarcoma and tumour-specific immunity.

Influence of whole body irradiation on bcg contact suppression of a rat sarcoma and tumour-specific immunity.

The Influence of Whole-Body Irradiation on Calcium and Phosphate Homeostasis in the Rat

PENTO, J. T., AND KENNY, A. D. The Influence of Whole-Body Irradiation on Calcium and Phosphate Homeostasis in the Rat. Radiat. Res. 63, 468-473 1975. Previous irradiation studies have revealed marked alterations in calcium metabolism. Moreover, the maintenance of calcium homeostasis with parathyroid hormone or calcium salts has been reported to reduce radiation lethality. Therefore, the present study was designed to evaluate the influence of irradiation on calcium homeostasis in the rat. Nine hundred rad of whole-body irradiation produced a significant depression of both plasma calcium and phosphate at 4 days postirradiation. This effect of irradiation was observed to be dose-dependent over a range of 600-1200 rad, and possibly related to irradiation-induced anorexia. The physiological significance of these observations is discussed.

Course of the post-irradiation syndrome after irradiation with lethal doses in newborn conventional, germ-free and Escherichia coli-monoassociated piglets.

The influence of whole-body irradiation with lethal doses of ionizing radiation (60Co) was studied in conventional, germ-free andEscherichia coli-monoassociated newborn piglets. The dose 1,200 R produced an acute intestinal death (i.e. within 3–4 days) in conventional animals, whereas survival was three times as long in their germ-free counterparts. Artificial colonization of the intestinal tract of germ-free piglets with non-pathogenic strain ofEscherichia coli, prior to irradiation with the same dose, produced the conventionalization of these animals and reduction in the survival time almost to the level of conventional animals. In conventional animals, profound focal regressive changes of the epithelium accompanying the denudation of intestinal villi were found already on the 2nd–3rd day after irradiation with 1,200 R. On the other hand, the intestinal epithelium of germ-free piglets, irradiated with 1,200 R, was found to be intact on the 7th–9th day of post-irradiation, and the first signs of damage started to occur around the 9–10th days. The morphological characteristics of the intestinal mucous membrane ofEscherichia coli-monoassociated piglets were comparable to those of conventional, irradiated piglets. The role of the presence of the microbial factor for the turnover and radiosensitivity-resistance of enterocytes, and for the survival-death rate of animals irradiated with doses producing the post-irradiation gastro-intestinal syndrome, is discussed.