Irradiated Rats Research Articles

The probable radioprotective role of Acacia nilotica L. against biochemical and cytogenetic disorders induced in gamma irradiated male rats

Gum Arabic (Acacia nilotica L.) is a respected plant that has many nutrients and curative practices. It hinders, improves, or manages many disorders. The radio-protective activity of Acacia nilotica was investigated against γ-rays-induced testicle damage in rats. Twenty-four rats were correspondingly distributed into 4 groups; control, Acacia nilotica (15mg/kg, daily for 30 days), γ-irradiated (5Gy γ-rays, single dose) and Acacia nilotica plus γ-rays treated groups. The plasma testosterone and total antioxidant status (TAS) were estimated. Lipid peroxidation; malondialdehyde (MDA), reduced glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), also glutathione peroxidase (GPx), catalase (CAT), tumor necrosis factor-α (TNF-α) with interleukin-1β (IL-1β), were determined in the testicle tissues. A testis weight, sperm count and motility, peripheral-blood and bone-marrow micronuclei (PMN and BMN), and frequency of chromosomal aberrations (CAs) were scored. A significant decline in the levels of plasma testosterone with TAS observed in the γ-irradiated rats. The results also showed significantly increased levels of testicle MDA, inflammatory markers, PMN, BMN and CAs frequencies and decrease in testes weight, sperm count and motility and levels of testicle antioxidants markers in gamma irradiated group. All these biochemical and fertility indices results were significantly enhanced in the Acacia nilotica plus γ-rays treated groups. However, the possible alleviate activity of Acacia nilotica on γ-rays-induced testicle injury in rats has not previously conversed, and this is the topic of this study.

Difference in the occurrence of capsular contracture according to the characteristics of the tissue in an irradiated rat model.

In this study, it was hypothesized that the capsule formation varies according to the radiation dose in the muscle tissues; chest wall tissues, including the ribs; and acellular dermal matrices (ADM) that are in contact with the silicone implant. This study consisted of 20 SD rats that underwent submuscular plane implant reconstruction using ADM. They were divided into four groups: Group 1 as the un-radiated control (n = 5), Group 2 with non-fractionated radiation at a dose of 10 Gy (n = 5), Group 3 with non-fractionated radiation at a dose of 20 Gy (n = 5), and Group 4 with fractionated radiation at a dose of 35 Gy (n = 5). Three months after surgery, hardness was measured. Moreover, the histology and immunochemistry of the capsule tissues of the ADM, muscle tissues, and chest wall tissues were analyzed. As the radiation dose increased, the silicone implant became harder. But no significant difference in capsule thickness according to the radiation dose was observed. Based on the tissue in contact with the silicone implant, ADM has a thinner capsule thickness than the muscle tissues and less inflammation as well as less neovascularization compared with the other tissues. This study described a new rat model of clinically relevant implant-based breast reconstruction using a submuscular plane and ADM with irradiation. Therefore, it was confirmed that the ADM in contact with the silicone implant, even after irradiation, was protected from radiation compared with the other tissues.

The effect of human recombinant epidermal growth factor on capsule contraction in an irradiated rat model

The effect of human recombinant epidermal growth factor on capsule contraction in an irradiated rat model

Analysis of the urinary metabolic profiles in irradiated rats treated with Activated Protein C (APC), a potential mitigator of radiation toxicity

Purpose The goal of the current study was to identify longitudinal changes in urinary metabolites following IR exposure and to determine potential alleviation of radiation toxicities by administration of recombinant APC formulations. Materials and methods Female adult WAG/RijCmcr rats were irradiated with 13.0 Gy leg-out partial body X-rays; longitudinally collected urine samples were subject to LC-MS based metabolomic profiling. Sub-cohorts of rats were treated with three variants of recombinant APC namely, rat wildtype (WT) APC, rat 3K3A mutant form of APC, and human WT APC as two bolus injections at 24 and 48 hours post IR. Results Radiation induced robust changes in the urinary profiles leading to oxidative stress, severe dyslipidemia, and altered biosynthesis of PUFAs, glycerophospholipids, sphingolipids, and steroids. Alterations were observed in multiple metabolic pathways related to energy metabolism, nucleotide biosynthesis and metabolism that were indicative of disrupted mitochondrial function and DNA damage. On the other hand, sub-cohorts of rats that were treated with rat wildtype-APC showed alleviation of radiation toxicities, in part, at the 90-day time point, while rat 3K3A-APC showed partial alleviation of radiation induced metabolic alterations 14 days after irradiation. Conclusions Taken together, these results show that augmenting the Protein C pathway and activity via administration of recombinant APC may be an effective approach for mitigation of radiation induced normal tissue toxicity.

Protective Potentials of Alpha-Lipoic Acid against Ionizing Radiation-Induced Brain Damage in Rats.

This study was aimed at determining the effects of alpha-lipoic acid on ionizing irradiation-induced oxidative damage and apoptosis in the brain of rats. The animals were exposed to whole-brain X-radiation with a 15 Gy single dose in the absence or presence of alpha-lipoic acid (200 mg/kg body weight) pretreatment for one week. The rats were divided into four groups (5 rats in each group): vehicle control, alpha-lipoic acid alone (ALA), radiation alone (RAD), and radiation plus alpha-lipoic acid (RAD+ALA). In the next stage, malondialdehyde (MDA), nitric oxide, catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the brain tissue of the rats were measured. Furthermore, the Western blot analysis technique was performed to assess the NOX2, NOX4, and caspase-3 protein expression levels. Twenty-four hours after the irradiation, MDA and nitric oxide levels in the irradiated rats were significantly higher than those in the control group (p < 0.001); however, the pretreatment with alpha-lipoic acid resulted in a significant reduction in these stress oxidative markers (p < 0.05). Moreover, a significant decrease in CAT, SOD, and GPx levels was observed in the radiation group alone compared to the control group (p < 0.01); in contrast, the activities of these antioxidant enzymes significantly increased in the radiation plus alpha-lipoic acid group in comparison to the radiation group alone (p < 0.05). The results of Western blot analysis revealed that NOX2, NOX4, and caspase-3 protein expressions significantly elevated in the irradiated rats compared to the control group (p < 0.001). The pretreatment with alpha-lipoic acid could significantly decrease the expression levels of NOX2, NOX4, and caspase-3 in comparison with the radiation group alone (p < 0.05). According to the obtained findings, it can be mentioned that the alpha-lipoic acid pretreatment could mitigate the ionizing irradiation-induced oxidative damage and apoptosis in the brain of the rats.

Dose- and Segment-Dependent Disturbance of Rat Gut by Ionizing Radiation: Impact of Tight Junction Proteins.

The damaging effect of ionizing radiation (IR) exposure results in the disturbance of the gut natural barrier, followed by the development of severe gastrointestinal injury. However, the dose and application segment are known to determine the effects of IR. In this study, we demonstrated the dose- and segment-specificity of tight junction (TJ) alteration in IR-induced gastrointestinal injury in rats. Male Wistar rats were subjected to a total-body X-ray irradiation at doses of 2 or 10 Gy. Isolated jejunum and colon segments were tested in an Ussing chamber 72 h after exposure. In the jejunum, 10-Gy IR dramatically altered transepithelial resistance, short-circuit current and permeability for sodium fluorescein. These changes were accompanied by severe disturbance of histological structure and total rearrangement of TJ content (increased content of claudin-1, -2, -3 and -4; multidirectional changes in tricellulin and occludin). In the colon of 10-Gy irradiated rats, lesions of barrier and transport functions were less pronounced, with only claudin-2 and -4 altered among TJ proteins. The 2-Gy IR did not change electrophysiological characteristics or permeability in the colon or jejunum, although slight alterations in jejunum histology were noted, emphasized with claudin-3 increase. Considering that TJ proteins are critical for maintaining epithelial barrier integrity, these findings may have implications for countermeasures in gastrointestinal acute radiation injury.

Morphology of the epithelium of the fallopian tubes of rats under the influence of chronic low-intensity γ-radiation

The purpose of the study was to investigate the functional morphology of the ciliary transport system of the fallopian tubes of sexually mature rats under the influence of chronic low-intensity γ-radiation.Material and methods. Using a complex technique of intravital microscopic observation, the motor activity of the ciliary apparatus was studied. The frequency of the main types of epithelial cells in the layer was determined on histological sections stained with hematoxylin and eosin. There was also determined morphometry of digitized images of cell structures (cell height, length of cilia) of the epithelial lining of the fallopian tubes of 16 female Wistar rats subjected to experimental chronic γ-irradiation for 55–70 days (total absorbed doses – 5 cGy and 50 cGy) and 8 control animals that were under natural background radiation.Results. The epithelium of the fallopian tubes in the control and experiment in rats contains three types of cells: ciliated, secretory and intercalary (cambial). Compared to the control of the irradiated rats the average height of ciliated cells and the length of cilia were decreased by 30% and 23%, respectively, at a total absorbed dose of 5 cGy and by 16% and 13% at 50 cGy (p 18% (p recorded, while the dimensional characteristics of secretory cells did not significantly differ from the control (p&gt;0,05).Conclusions. The effects of chronic low-intensity γ-radiation on the epithelial lining of the fallopian tubes can be clearly manifested at the level of physiological reactions of cells; irradiation at a minimum dose of 5 cGy is already capable of causing atrophic rearrangements and dysfunction of the ciliated epithelium. The results obtained indicate a high radiosensitivity of the studied tissue elements and make it possible to consider chronic ionizing radiation as a potential risk factor disrupting the structure and function of the epithelial lining of the organ.

THE INFLUENCE OF ENTEROSORPTION ON SYSTEM “TUMOR AND HOST” AND TOXIC MANIFESTATIONS OF SOME CHEMOTHERAPEUTIC AGENTS

Summary. Development of malignant neoplasms is a serious pathological condition accompained by a significant body intoxication. Complex application of surgery, radiation and chemotherapy greatly improves the results of treatment of the patients with cancer, however, their toxic effects are enhanced that manifested as suppression of hematopoesis, immunosupression, nephrotoxicity, hepatotoxicity, cardiotoxicity. Enterosorption using highly active carbon sorbents is one of the perspective methods of overcoming endotoxicosis caused by systemic intoxication. The results of the study obtained on laboratory animals, namely on mice with Leweis lung carcinoma, rats with Geren’s carcinoma treated with cisplatin, rats treated with melphalan, doxorubicin, as well as irradiated rats, showed excellent efficiency of carbon enterosorbents in reducing the toxic manifestations of radiation and chemotherapy. The enterosorbents showed a myeloprotective action, lead to significant improvement of some haematological and biochemical parameters of blood and reduced manifestations of oxidative stress and the level of endogenous intoxication.

EXPERIMENTAL BACKGROUND FOR HORMONE-VITAMIN COMPLEX USING IN COURSE OF REHABILITATION AFTER IONIZING RADIATION.

The aim: To determine the efficacy of the original hormone-vitamin complex in terms of biochemical activity enhancement and muscle system functional activity restoration in the irradiated rat's descendents. Materials and methods: The activity of NADP-dependent malatedehydrogenase and the content of ATP, ADP and AMP were determined in the blood, myocardium and thigh muscles of rats exposed to ionizing gamma-radiation. The rats were also checked in the forced swimming test. The efficacy of the hormone-vitamin complex was determined in all mentioned indexes. Results: Our results testify the expressed changes in muscle tissue functioning in an irradiated person, which was expressed by the dysfunction of biochemical reactions aimed at synthetic energy processes, and by the macroergic compounds level depletion together with physical performance minimization. Our data showed the hormone-vitamin complex injection to irradiated animals and their descendants improved the muscle energy resources due to glycolytic substrate phosphorylation enhancement and due to tricarboxylic acids cycle oxidative potential strengthening. Conclusions: Original scheme of post-radiation lesions complex pharmacological correction prevented the development of tissues providing with macroergic compounds, anaerobic processes strengthening, metabolic acidosis, weakening of both substrate phosphorylation and tricarboxylic acids cycle. The original scheme of ionizing radiation-induced energetic disorders pharmacological corrections in the irradiated animals' descendents we consider as an experimental basis for the reasonability of these compound radioprotective effects testing during the physiotherapeutic treatment of persons exposed to ionizing radiation.

Effects of hyaluronic acid and chondroitin sulfate on acute radiation proctitis in rats.

This study was designed to investigate the prophylactic and therapeutic effects of hyaluronic acid and chondroitin sulfate combination (HA/CS) on a model of acute radiation proctitis. Rats were divided into five groups: SHAM; irradiation (IR) + saline (1 mL for 5th and 10th day); IR + HA/CS (1 mL for 5th and 10th day). A single fraction of 17.5 Gy was delivered to each rat. HA/CS was administered rectally each day after irradiation. Each rat was observed daily for signs of proctitis. Irradiated rats were euthanized on days 5 and 10. The mucosal changes were evaluated macroscopically and pathologically. According to the clinical findings, five rats in the irradiation + saline group showed grade 3-4 symptoms on the 10th day. No significant difference in the macroscopic finding scores on the 5th day was observed between the irradiation + saline and irradiation + HA/CS groups. In the pathological examination, radiation-induced mucosal damage was the most prominent finding 10 days after irradiation in saline-treated rats. On the 10th day, the irradiation + HA/CS group showed mild inflammation and slight crypt changes, which corresponded to grade 1-2 pathological findings. We think that HA/CS used in radiation cystitis can be beneficial for radiation proctitis.

Fine motor deficits exhibited in rat string-pulling behavior following exposure to sleep fragmentation and deep space radiation.

Deep space flight missions will expose astronauts to multiple stressors, including sleep fragmentation and space radiation. There is debate over whether sleep disruptions are an issue in deep space. While these stressors independently impair sensorimotor function, the combined effects on performance are currently unknown. String-pulling behavior involves highly organized bimanual reach-to-grasp and withdraw movements. This behavior was examined under rested wakeful conditions and immediately following one session of sleep fragmentation in Sham and irradiated rats 3months after exposure (10cGy 4Helium or 5-ion simulated Galactic Cosmic Radiation). Sleep fragmentation disrupted several aspects of string-pulling behavior, such that rats' ability to grasp the string was reduced, reach endpoint concentration was more variable, and distance traveled by the nose increased in the Y-range compared to rested wakeful performance. Overall, irradiated rats missed the string more than Sham rats 3months post-exposure. Irradiated rats also exhibited differential impairments at 3months, with additional deficits unveiled after sleep fragmentation. 4Helium-exposed rats took longer to approach the string after sleep fragmentation. Further, rats exposed to 4Helium traveled shorter withdraw distances 3months after irradiation, while this only emerged in the other irradiated group after sleep fragmentation. These findings identify sleep fragmentation as a risk for fine motor dysfunction in Sham and irradiated conditions, in addition to radiation exposure. There may be complex temporal alterations in performance that are stressor- and ion-dependent. Thus, it is critical to implement appropriate models of multi-flight stressors and performance assessments in preparation for future deep space flight missions.

Ginsenoside Rk1 attenuates radiation-induced intestinal injury through the PI3K/AKT/mTOR pathway

Radiation-induced intestinal injury (RIII) frequently occurs during radiotherapy; however, methods for treating RIII are limited. Ginsenoside Rk1 (RK1) is a substance that is derived from ginseng, and it has several biological activities, such as antiapoptotic, antioxidant and anticancer activities. The present study was designed to investigate the potential protective effect of Rk1 on RIII and the potential mechanisms. The results showed that RK1 treatment significantly improved the survival rate of the irradiated rats and markedly ameliorated the structural injury of the intestinal mucosa observed by histology. Treatment with RK1 significantly alleviated radiation-induced intestinal epithelial cell oxidative stress apoptosis. Moreover, RNA-Seq identified 388 differentially expressed genes (DEGs) and showed that the PI3K-AKT pathway might be a key signaling pathway by which RK1 exerts its therapeutic effects on RIII. The western blotting results showed that the p-PI3K, p-AKT and p-mTOR expression levels, which were increased by radiation, were markedly inhibited by Rk1, and these effects were reversed by IGF-1. The present study demonstrates that Rk1 can alleviate RIII and that the mechanism underlying the antiapoptotic effects of RK1 may involve the suppression of the PI3K/Akt/mTOR pathway. This study provides a promising therapeutic agent for RIII.

DNA Methylation Alterations in Fractionally Irradiated Rats and Breast Cancer Patients Receiving Radiotherapy.

Radiation-Induced CardioVascular Disease (RICVD) is an important concern in thoracic radiotherapy with complex underlying pathophysiology. Recently, we proposed DNA methylation as a possible mechanism contributing to RICVD. The current study investigates DNA methylation in heart-irradiated rats and radiotherapy-treated breast cancer (BC) patients. Rats received fractionated whole heart X-irradiation (0, 0.92, 6.9 and 27.6 Gy total doses) and blood was collected after 1.5, 3, 7 and 12 months. Global and gene-specific methylation of the samples were evaluated; and gene expression of selected differentially methylated regions (DMRs) was validated in rat and BC patient blood. In rats receiving an absorbed dose of 27.6 Gy, DNA methylation alterations were detected up to 7 months with differential expression of cardiac-relevant DMRs. Of those, SLMAP showed increased expression at 1.5 months, which correlated with hypomethylation. Furthermore, E2F6 inversely correlated with a decreased global longitudinal strain. In BC patients, E2F6 and SLMAP exhibited differential expression directly and 6 months after radiotherapy, respectively. This study describes a systemic radiation fingerprint at the DNA methylation level, elucidating a possible association of DNA methylation to RICVD pathophysiology, to be validated in future mechanistic studies.

Muscle stem cells and fibro-adipogenic progenitors in female pelvic floor muscle regeneration following birth injury

Pelvic floor muscle (PFM) injury during childbirth is a key risk factor for pelvic floor disorders that affect millions of women worldwide. Muscle stem cells (MuSCs), supported by the fibro-adipogenic progenitors (FAPs) and immune cells, are indispensable for the regeneration of injured appendicular skeletal muscles. However, almost nothing is known about their role in PFM regeneration following birth injury. To elucidate the role of MuSCs, FAPs, and immune infiltrate in this context, we used radiation to perturb cell function and followed PFM recovery in a validated simulated birth injury (SBI) rat model. Non-irradiated and irradiated rats were euthanized at 3,7,10, and 28 days post-SBI (dpi). Twenty-eight dpi, PFM fiber cross-sectional area (CSA) was significantly lower and the extracellular space occupied by immune infiltrate was larger in irradiated relative to nonirradiated injured animals. Following SBI in non-irradiated animals, MuSCs and FAPs expanded significantly at 7 and 3 dpi, respectively; this expansion did not occur in irradiated animals at the same time points. At 7 and 10 dpi, we observed persistent immune response in PFMs subjected to irradiation compared to non-irradiated injured PFMs. CSA of newly regenerated fibers was also significantly smaller following SBI in irradiated compared to non-irradiated injured PFMs. Our results demonstrate that the loss of function and decreased expansion of MuSCs and FAPs after birth injury lead to impaired PFM recovery. These findings form the basis for further studies focused on the identification of novel therapeutic targets to counteract postpartum PFM dysfunction and the associated pelvic floor disorders.

SINGLE AND COMBINED EFFECTS OF 5GHZ FREQUENCY WAVES AND COMPUTED TOMOGRAPHY(CT) SCAN DOSES ON WHOLE BLOOD PARAMETRES, MEMORY AND P53 GENE EXPRESSION IN RATS

AbstractBackgroundExponential increase has emerged globally in the use of non‐ionizing and ionizing radio‐frequency electromagnetic fields(Rf‐emfs) for a wide range of applications, daily activities, communication, diagnostics , therapeutics to mention but a few. However, a significant public concern is how these technologies interacts and affects the biota as electromagnetic field (EMF) emissions is linked to dysregulation of genes involved in neurotransmission,oxidative stress and normal cellular function.MethodsStandard methods (y‐maze, novel object recognition tests, automated hematology analyzer, PCR etc), were used to study how the combination of EM waves from 5Ghz radio and CT irradiation affects whole blood parameters, neurobehavioural profiles (memory and cognition), DNA fragmentation and p53 gene expression in Wistar rats which were grouped into five namely: I‐Negative control, II‐sham, III‐5Ghz only , IV‐ 5Ghz+CT, V‐CT only for fourteen days. Genomic DNA was isolated from rats’ cerebral cortex while target gene and internal control primers (GAPDH) were synthesized for p53 gene exons expression and electrophoresed on a 2.5% agarose gel.ResultsWe found that CT irradiation had higher modulatory effects on platelets, white blood cell counts and memory impairments compared to 5GHz only group. However, there was gross DNA damage and complete loss of p53 (exons 5‐7) gene expression profiles in the 5GHz while the CT irradiated rats expressed mutant p53 gene. The effect of CT irradiation in pre‐exposed 5GHz rats revealed mutant p53(exons 5‐7), elevated memory and cognition impairments amongst others .ConclusionDeleterious single effects of 5GHz was observed in p53 gene expression profiles and cognition with an interferential interaction in its combination with CT irradiation leading to mutant p53 gene expression . The impaired neurobehavioural and p53 gene profiles as a result of the single and combined 5GHz and CT exposure predicts functional radiation waves emission effects, changes in resultant protein and dysregulated cellular functions.

Potential Protective Effect of Bromelain and Pineapple Extract on Gamma Irradiated Female Rats: A Study of Oxidative Stress, Apoptosis, and Hormonal Changes

Potential Protective Effect of Bromelain and Pineapple Extract on Gamma Irradiated Female Rats: A Study of Oxidative Stress, Apoptosis, and Hormonal Changes

Utility of melatonin in mitigating ionizing radiation-induced testis injury through synergistic interdependence of its biological properties

BackgroundIonizing radiations (IR) have widespread useful applications in our daily life; however, they have unfavorable effects on reproductive health. Maintaining testicular health following IR exposure is an important requirement for reproductive potential. The current study explored the role of melatonin (MLT) in mitigating IR-induced injury in young adult rat testis.MethodsRats were given daily MLT (25 mg/kg) for 3 and 14 days after receiving 4 Gy γ-radiation.ResultsSerum MLT levels and other antioxidants, including glutathione content, and the activity of glutathione peroxidase and glutathione reductase in the testis of the irradiated rats were remarkably maintained by MLT administration in irradiated rats. Hence, the hydrogen peroxide level declined with remarkably reduced formation of oxidative stress markers, 4-hydroxynonenal, and 8-Hydroxy-2′-deoxyguanosine in the testis of irradiated animals after MLT administration. The redox status improvement caused a remarkable regression of proapoptotic protein (p53, Cyto-c, and caspase-3) in the testis and improved inflammatory cytokines (CRP and IL-6), and anti-inflammatory cytokine (interleukin IL-10) in serum. This is associated with restoration of disturbed sex hormonal balance, androgen receptor upregulation, and testicular cell proliferation activity in irradiated rats, explaining the improvement of sperm parameters (count, motility, viability, and deformation). Consequently, spermatogenic cell depletion and decreased seminiferous tubule diameter and perimeter were attenuated by MLT treatment post irradiation. Moreover, the testis of irradiated-MLT-treated rats showed well-organized histological architecture and normal sperm morphology.ConclusionsThese results show that radiation-induced testicular injury is mitigated following IR exposure through synergistic interdependence between the antioxidant, anti-inflammatory, anti-apoptotic, and anti-DNA damage actions of MLT.

The effects of ultraviolet, gamma- and X-ray irradiation on the growth, antibacterial activity and radio-protective of Lactobacillus rhamnosus.

Ionizing radiation is widely applied in food production as preservation technology and for correction of the gut microbiome of cancer patients, rescuers, astronauts etc. Lactic acid bacteria (LAB) can be used for the same reason. The main goal of this study was to investigate the effect of irradiation on some activities of Lactobacillus rhamnosus MDC 9661 and its effect on the survival of irradiated rats. The results indicate that both ultraviolet (during 45 min) and X-ray irradiations (with 2 Sv) decreased the CFU and the antibacterial activity of the strain. Higher than 700 Sv dose of X-ray irradiation resulted in the total inhibition of antibacterial activity with the total reduction of colony forming units less than 10 cells ml-1 , while irradiated with 1000 Sv dose L. rhamnosus MDC 9661 did not lose its proteolytic activity. It was also shown that L. rhamnosus MDC 9661 was not immunogenic in the organism of the rats and cannot lead to the development of autoimmune responses. L. rhamnosus MDC 9661 demonstrated the necessary properties for probiotics and can be effectively used for the correction of the gut microbiome of all target groups. The co-aggregation of the cells is one of the mechanisms for resistance of LAB to irradiation.

The Difference in the Occurrence of Capsular Contracture According to the Characteristics of the Tissue in Contact with the Breast Implant in an Irradiated Rat Model

The Difference in the Occurrence of Capsular Contracture According to the Characteristics of the Tissue in Contact with the Breast Implant in an Irradiated Rat Model

Photobiomodulation therapy protects red blood cells against nitrative stress during streptozotocin-induced diabetes

Background. According to the International Diabetes Federation Diabetes Atlas, 10th edition, diabetes is responsible for 6.7 million deaths in 2021. Diabetes mellitus is a group of metabolic disorders characterized by hyperglycemia secondary to either resistance to insulin, insufficient insulin secretion, or both. Oxidative and nitrative stress is a vital part of the complex mechanism by which diabetes and its complications develop. It is known that Photobiomodulation therapy accelerates diabetic wound healing, treats relegated inflammation, and increases oxygen availability for cells. Although some basic molecular mechanisms caused by photobiomodulation therapy in different cell types are already known, they have not been studied in erythrocytes and are different due to the absence of central organelles such as nucleus and mitochondria. The aim of the study was to investigate the effect of photobiomodulation therapy on the development of nitrative stress in blood plasma and erythrocytes of rats from different experimental groups. Materials and Methods. The study was performed on white outbred male rats weighing 130–180 g. The diabetes mellitus was induced by intraperitoneal injection of streptozotocin (60 mg/kg). Rats were exposed to photobiomodulation with light-emitting diodes at a wavelength of 630–660 nm daily for 10 days. The irradiation time was 5 minu­tes. The content of nitrite and nitrate anions, total NO synthase activity, as well as the activity of its endothelial and inducible isoforms in red blood cells of rats were determined spectrophotometrically. Results and Discussion. Under streptozotocin-induced diabetes mellitus, the content of nitrite and nitrate anions and NO synthase activity increased in the rats’ red blood cells, as well as in blood plasma. Moreover, we found an increase in inducible NO synthase activity and nitrate ion content in red blood cells of irradiated healthy rats. Also, there was an increase in nitrite and nitrate ion content after photobiomodulation therapy in the blood plasma of healthy animals. On the other hand, irradiation caused a decrease in NO synthase activity with a parallel reduction in both nitrite and nitrate anions content in erythrocytes and blood plasma of rats with experimental diabetes. Conclusion. Photobiomodulation therapy protects rats’ red blood cells from nitrative stress during streptozotocin-induced diabetes mellitus.