The effect of hyperbaric oxygen therapy on rhabdomyolysis-induced myoglobinuric acute renal failure in rats

Hyperbaric Oxygenation: Can It Be a Novel Supportive Method in Acute Kidney Injury? Data Obtained from Experimental Studies

Despite constant achievements in treatment, acute kidney injury (AKI) remains a significant public health problem and a cause of mortality in the human population. In developed countries, AKI is a significant and frequent hospital complication, especially among patients admitted to intensive care units, where mortality rates can reach up to 50%. In addition, AKI has been implicated as an independent risk factor for the development of chronic kidney disease. Hyperbaric oxygenation (HBO) has been used as a primary or adjunctive therapy for the past 50 years, both in experimental and clinical studies. HBO is a treatment in which the patient is occasionally exposed to 100% oxygen at a pressure greater than atmospheric pressure at sea level. However, despite decades of extensive research, the potentially beneficial effects of this therapeutic approach are still not fully understood, although many potential mechanisms have been proposed, such as antioxidative, anti-inflammatory, anti-apoptotic, etc. Furthermore, the low cost and insignificant adverse events make HBO a potentially important strategy in the prevention and treatment of different diseases. Considering all of this, this review highlights the potential role of HBO in maintaining cellular homeostasis disrupted due to AKI, caused in different experimental models.

Rhabdomyolysis, myoglobinuric nephrosis, and crystalline nephropathy in a captive bottlenose dolphin

A 5-y-old female bottlenose dolphin (Tursiops truncatus) from an aquarium in Japan had clinical signs of anorexia, vomiting, and bradykinesia. Enrofloxacin and lactated Ringer solution were administered for treatment of bacterial infection and for rehydration. Elevations of creatine kinase and aspartate aminotransferase activities were detected on day 4 of treatment, indicating that rhabdomyolysis had developed on day 3. On day 5, serum creatinine and urea concentrations increased and remained high throughout the remaining treatment; the dolphin died on day 16. Postmortem examination revealed massive necrosis of the longissimus dorsi muscles. Histologic examination revealed extensive necrosis of skeletal myofibers, multifocal renal tubular necrosis with intratubular casts and crystals, and suppurative bronchopneumonia. The renal casts labeled positively with anti-myoglobin antibody; expression of aquaporin-1 was decreased in renal tubules compared to normal kidney tissue. To our knowledge, this description of clinicopathologic findings of rhabdomyolysis leading to acute kidney injury with concomitant crystalline nephropathy has not been reported previously in a bottlenose dolphin.

Renal Effects of Hyperbaric Oxygen Therapy in Patients with Diabetes Mellitus: A Retrospective Study

Hyperbaric oxygen therapy (HBOT) is an adjunctive treatment for patients with diabetic foot ulcers. The prolonged high oxygen level used in HBOT can produce oxidative stress, which may be harmful to the kidney. Animal experiments suggest HBOT does not harm renal function and may have an antiproteinuric effect, but little is known on the effect of HBOT in humans. We performed a retrospective chart review of 94 patients with diabetes mellitus who underwent HBOT at our institution over an eight-year period. Thirty-two patients had serum creatinine levels within 60 days of the start and the end of treatment. Creatinine levels were 1.41 ± 0.89 mg/dl before and 1.52 ± 1.17 mg/dl after hyperbaric treatments with no statistically significant difference (mean (postcreatinine + precreatinine/2) = 0.10 mg/dl, SE = 0.11, t = 0.89). Twenty-three patients had proteinuria measurements before and after HBOT mainly by urine dipstick analysis. A Wilcoxon signed-rank test showed less proteinuria after HBOT than before (N = 23, p=0.002). Proteinuria was absent in 7 of 23 patients (30%) before HBOT and 13 of 23 patients (57%) after HBOT, a reduction by almost 50%. This observation is remarkable because oxidative stress might be expected to increase rather than decrease proteinuria.

Ramipril blunts glycerol-induced acute renal failure in rats through its antiapoptosis, anti-inflammatory, antioxidant, and renin-inhibiting properties

OBJECTIVES

Acute kidney injury (AKI) is a malady with a sudden onset resulting in buildup of waste matters in the body, but a specific cure hasn't been found as a lasting solution to AKI. In this study, ramipril was evaluated for its potential therapy in glycerol-induced AKI in rats.

METHODS

Twenty animals were divided into four groups of five animals each. Group I was the control while group II was given glycerol on day 8 only, groups III and IV were administered with pioglitazone (reference drug) and ramipril for seven days respectively and on day 8 received glycerol. On the ninth day, blood and tissue samples were taken to assay for serum indicators of oxidative damage, enzymatic and nonenzymatic antioxidants, and creatinine and blood urea nitrogen. Animals were sacrificed thereafter; kidney was harvested for histological and immunohistochemical analysis. Expressions of caspase 3, renin receptor, NK-KB, and KIM-1 were carried out.

RESULTS

Ramipril significantly inhibited indicators of oxidative damage while also significantly increasing levels of enzymatic and nonenzymatic antioxidant markers. These drugs also significantly lowered the levels of creatinine and blood urea nitrogen. Histology also indicated that while there were massive infiltration of leucocytes and congestion of the kidney in toxicant group, the ramipril-treated group showed a milder condition. In immunohistochemistry, the two drugs significantly inhibited the expressions of the four proteins, which were highly expressed in the toxicant group.

CONCLUSIONS

The study showed that ramipril and pioglitazone have nephroprotective effect and thus have the ability to blunt AKI through their anti-inflammatory, antiapoptosis, antirenin, and antioxidant properties.

Luteolin Attenuates Glycerol-Induced Acute Renal Failure and Cardiac Complications Through Modulation of Kim-1/NF-κB/Nrf2 Signaling Pathways

Acute renal failure (ARF) has been documented as a life-threatening disease with high morbidity and mortality. We investigated the protective effect of Luteolin against ARF. In this study, forty-male Wistar albino rats were randomly divided into four groups (n = 10). Group A received normal saline. Group B received glycerol (10 ml/kg BW, 50% v/v in sterile saline, i.m.). Groups C and D were pretreated with Luteolin 100 and 200 mg/kg for 7 days, and thereafter administered Glycerol (10 ml/kg BW, 50% v/v in sterile saline, i.m.). Administration of glycerol significantly increased systolic blood pressure, diastolic blood pressure and mean arterial pressure. Renal protein carbonyl and xanthine oxidase increased significantly while significant reduction in the activity of renal glutathione peroxidase, glutathione S-transferase and glutathione reductase was observed in the glycerol intoxicated rats. Furthermore, administration of glycerol led to significant increases in serum creatinine and blood urea nitrogen together with reduction in nitric oxide (NO) bioavailability. Immunohistochemistry revealed that glycerol intoxication enhanced expressions of kidney injury molecule 1, nuclear factor kappa beta and cardiac troponin (CTnI). However, Luteolin pretreatment normalized blood pressure, reduced markers of oxidative stress, renal damage, and improved NO bioavailability. Luteolin also downregulated the expressions of kidney injury molecule 1, nuclear factor kappa beta and cardiac troponin. Together, Luteolin might open a novel therapeutic window for the treatment of acute renal failure and cardiac complication.

Clinical utility of hyperbaric oxygen therapy in genitourinary medicine

Hyperbaric oxygen therapy (HBOT) is a medical technique which delivers oxygen at ambient pressures to increase the amount of dissolved oxygen in the blood and oxygen distribution to tissues. There are several beneficial properties of HBOT concomitant with elevated oxygen distribution in tissue including anti-inflammation, angiogenesis through vascular endothelial growth factor proliferation, augmented fibroblast activity through fibroblast growth factor proliferation, tissue and wound repair, enhancement of lymphocyte and macrophage activity, increased male testosterone secretion, and bactericidal activity. Given its renown in treating conditions such as decompression sickness and carbon monoxide poisoning, HBOT is making gradual strides for use in genitourinary medicine due to its low risk and likeliness to achieve favorable results. Early success has been observed in the treatment of Fournier's gangrene, radiation cystitis, and interstitial cystitis via the elimination of clinical symptoms such as pain. Further indications that have exhibited positive outcomes despite HBOT's ambiguous mechanism of action include cyclophosphamide hemorrhagic cystitis, emphysematous cystitis, pelvic radiation disease, radiation-induced proctopathy, dystrophic calcification of the prostate, erectile dysfunction secondary to urethroplasty, priapism, abnormal renal morphology, blood testosterone, calcific uremic arteriolopathy, and hidradenitis suppurativa. For other indications, multicenter studies must be conducted to determine HBOT's true efficacy, mechanism of action, risks, and advantages over conventional treatments.

The Preventive Role of Pioglitazone in Glycerol-Induced Acute Kidney Injury in Rats during Two Different Treatment Periods

BACKGROUND

Acute kidney injury is the most life-threatening complication of rhabdomyolysis. Glycerol is commonly used to induce this injury. The aim was to investigate the renoprotective effects of pioglitazone and the possible advantage of administering the drug for a longer period.

METHODS

Twenty-four male Albino Wistar rats were randomly divided into 4 groups (n=6/group): (A) control, (B) glycerol (50%, 10 mL/kg intramuscularly), (C) glycerol+pioglitazone (10 mg/kg orally for 3 days), and (D) glycerol+pioglitazone (for 6 days). Serum urea and creatinine levels were measured to assess the renal function. Reduced glutathione (GSH) levels and histological alterations were also measured. Statistical analysis was performed using Prism (version 6). The numerical data were evaluated by ANOVA, followed by the Tukey tests. The categorical data were evaluated by the Mann-Whitney test and the Fisher exact tests. P<0.05 was considered significant.

RESULTS

In the glycerol-injected rats, the serum urea and creatinine levels were increased (P<0.001), while the GSH levels were decreased (P<0.001) compared to Group A. The nephrotoxicity showed significant tubular (P=0.01) and glomerular (P=0.02) injuries. In the pioglitazone-treated rats, the changes in the serum biomarkers and in the GSH levels were reversed in Group C (P=0.01) and in Group D (P=0.01). The microscopic examinations of the kidneys also showed some improvement. No obvious statistically significant difference was found between these 2 preventive groups in most studied features.

CONCLUSION

These results indicate that pioglitazone might have nephroprotective effects in this injury model. Pioglitazone succeeded in producing this effect within 3 days. Doubling the drug administration period did not produce any significant superior benefit.