Glycerol Administration Research Articles

Dietary Supplementation of Crossbred Pigs with Glycerol, Vitamin C, and Niacinamide Alters the Composition of Gut Flora and Gut Flora-Derived Metabolites.

The addition of glycerin, vitamin C, and niacinamide to pig diets increased the redness of longissimus dorsi; however, it remains unclear how these supplements affect gut microbiota and metabolites. A total of 84 piglets (20.35 ± 2.14 kg) were randomly allotted to groups A (control), B (glycerin-supplemented), C (vitamin C and niacinamide-supplemented), and D (glycerin, vitamin C and niacinamide-supplemented) during a feeding experiment. Metagenomic and metabolomic technologies were used to analyze the fecal compositions of bile acids, metabolites, and microbiota. The results showed that compared to pigs in group A, pigs in group D had lower virulence factor expressions of lipopolysaccharide (p < 0.05), fatty acid resistance system (p < 0.05), and capsule (p < 0.01); higher fecal levels of ferric ion (p < 0.05), allolithocholic acid (p < 0.01), deoxycholic acid (p < 0.05), tauroursodeoxycholic acid dihydrate (p < 0.01), glycodeoxycholic acid (p < 0.05), L-proline (p < 0.01) and calcitriol (p < 0.01); and higher (p < 0.05) abundances of iron-acquiring microbiota (Methanobrevibacter, Clostridium, Clostridiaceae, Clostridium_sp_CAG_1000, Faecalibacterium_sp_CAG_74_58_120, Eubacteriales_Family_XIII_Incertae_Sedis, Alistipes_sp_CAG_435, Alistipes_sp_CAG_514 and Methanobrevibacter_sp_YE315). Supplementation with glycerin, vitamin C, and niacinamide to pigs significantly promoted the growth of iron-acquiring microbiota in feces, reduced the expression of some virulence factor genes of fecal pathogens, and increased the fecal levels of ferric ion, L-proline, and some secondary bile acids. The administration of glycerol, vitamin C, and niacinamide to pigs may serve as an effective measure for muscle redness improvement by altering the compositions of fecal microbiota and metabolites.

Renoprotective effect of thymoquinone against rhabdomyolysis-induced acute kidney injury in the rat model.

Rhabdomyolysis leads to the release of myoglobin, sarcoplasmic proteins, and electrolytes into the blood circulation causing acute kidney injury (AKI). Thymoquinone, a natural compound found in Nigella sativa seeds, has antioxidant and anti-inflammatory effects. This investigation assessed the renoprotective effect of thymoquinone on rhabdomyolysis-induced AKI in rats. Male Wistar rats were categorized into six groups (n = 6): 1. Control: (normal saline), 2. Glycerol (50 ml/kg, single dose, IM), 3-5: Glycerol + thymoquinone (1, 2.5 and 5 mg/kg, 4 days, IP), 6. Thymoquinone (5 mg/kg). On day 5, serum and kidney tissue were isolated and the amounts of serum creatinine and blood urea nitrogen (BUN), renal malondialdehyde (MDA), glutathione (GSH.), tumor necrosis factor-alpha (TNF-α), neutrophil gelatinase-associated lipocalin (NGAL), and pathological changes were evaluated. Glycerol increased creatinine, BUN, MDA, TNF-α, and NGAL levels. It decreased GSH amounts and caused renal tubular necrosis, glomerular atrophy, and myoglobin cast in kidney tissue. Co-administration of glycerol and thymoquinone reduced creatinine, BUN, histopathological alterations, and MDA levels, and enhanced GSH amounts. Administration of glycerol and thymoquinone (5 mg/kg) had no significant effect on TNF-α amount but decreased NGAL protein levels. The administration of thymoquinone (5 mg/kg) alone did not display a significant difference from the control group. Rhabdomyolysis from glycerol injection in rats can cause kidney damage. Thymoquinone may attenuate renal dysfunction and oxidative stress. However, the TNF-α level was not significantly affected. Further studies are needed to explore the potential therapeutic effects of thymoquinone in managing AKI.

Renal protection by ellagic acid in a rat model of glycerol-induced acute kidney injury.

Studies conducted on animal models have shown that the administration of glycerol can lead to kidney tissue damage and impaired renal function. This is believed to be caused by oxidative stress and inflammation, which in turn can result in elevated levels of blood urea nitrogen (BUN) and creatinine. These metabolites are commonly used as indicators of renal function. The aim of the current experimental research was to investigate the protective efficacy of ellagic acid in a rat model of rhabdomyolysis induced by glycerol. Sixty healthy adult male Wistar rats weighing between 250 - 300 g were divided into five equal groups including control, rhabdomyolysis (administered 8.00 mL kg-1 of glycerol), and three rhabdomyolysis plus various doses of ellagic acid (25.00, 50.00 and 100 mg kg-1 per day; 72 hr after receiving glycerol for 14 days successively) groups. Serum levels of BUN, creatinine, lactate dehydrogenase, alkaline phosphatase, electrolytes and inflammatory cytokines were evaluated in all rats. Histopathological studies were also performed on kidney tissues from all groups. The administration of ellagic acid resulted in a significant increase in renal function biomarkers compared to the rats with acute kidney injury. This increase was consistent with notable reductions in tumor necrosis factor-α levels and increases in interleukin-10 levels observed in blood samples. Furthermore, the improvement in histopathological indices observed in rats received ellagic acid confirmed its nephroprotective role. The results of the current experimental study suggest that ellagic acid can improve kidney damage following glycerol injection, potentially by modulating the inflammatory process.

Legal Performance-enhancing Drugs Alter Course and Treatment of Rhabdomyolysis-induced Acute Kidney Injury.

Rhabdomyolysis-induced acute kidney injury (RIAKI) can interrupt physical training and increase mortality in injured warfighters. The legal performance-enhancing drugs caffeine and ibuprofen, which can cause renal injury, are widely used by service members. Whether caffeine or ibuprofen affects RIAKI is unknown. Cilastatin treatment was recently identified as an experimental treatment to prevent RIAKI at injury. To determine potential interacting factors in RIAKI treatment, we test the hypothesis that caffeine and ibuprofen worsen RIAKI and interfere with treatment. In mice, RIAKI was induced by glycerol intramuscular injection. Simultaneously, mice received caffeine (3 mg/kg), ibuprofen (10 mg/kg), or vehicle. A second cohort received volume resuscitation (PlasmaLyte, 20 mL/kg) in addition to caffeine or ibuprofen. In a third cohort, cilastatin (200 mg/kg) was administered concurrently with drug and glycerol administration. Glomerular filtration rate (GFR), blood urea nitrogen (BUN), urine output (UOP), renal pathology, and renal immunofluorescence for kidney injury molecule 1 were quantified after 24 hours. Caffeine did not worsen RIAKI; although BUN was modestly increased by caffeine administration, 24-hour GFR, UOP, and renal histopathology were similar between vehicle-treated, caffeine-treated, and caffeine + PlasmaLyte-treated mice. Ibuprofen administration greatly worsened RIAKI (GFR 14.3 ± 19.5 vs. 577.4 ± 454.6 µL/min/100 g in control, UOP 0.5 ± 0.4 in ibuprofen-treated mice vs. 2.7 ± 1.7 mL/24 h in control, and BUN 264 ± 201 in ibuprofen-treated mice vs. 66 ± 21 mg/dL in control, P < .05 for all); PlasmaLyte treatment did not reverse this effect. Cilastatin with or without PlasmaLyte did not reverse the deleterious effect of ibuprofen in RIAKI. Caffeine does not worsen RIAKI. The widely used performance-enhancing drug ibuprofen greatly worsens RIAKI in mice. Standard or experimental treatment of RIAKI including the addition of cilastatin to standard resuscitation is ineffective in mice with RIAKI exacerbated by ibuprofen. These findings may have clinical implications for the current therapy of RIAKI and for translational studies of novel treatment.

N-Acetylcysteine Improves Renal Function and Reduces Tissue Malondialdehyde Levels in Glycerol-Induced Acute Kidney Injury

Introduction: The etiology of myoglobinuric acute kidney injury involves oxidative injury brought on by the Fenton reaction and myoglobin redox cycle. Renal tubules may be harmed, and lipid peroxidation compounds with vasoconstrictor characteristics may be produced. N-acetylcysteine (NAC) is an antioxidant shown to improve renal microcirculation and have protective effects in various models of renal damage. The aim of the study was to demonstrate the protective impact of NAC in glycerol-induced rats by measuring tissue malondialdehyde (MDA) level and renal function test (RFT), and to determine the correlation between the protective effect and NAC dose.Methods: This study measured tissue malondialdehyde (MDA) and renal function to examine any protective effect of NAC in a glycerol-induced rat model and to determine whether the effect was dose-related. Five groups of male Wistar rats were used: 1) saline control group, (2) glycerol (50%, 8mL/kg, i.m) plus saline i.v group, 3) glycerol plus NAC (100 mg/kg)-treated group, 4) glycerol plus NAC (200 mg/kg)-treated group, 5) glycerol plus NAC (400 mg/kg)-treated group. At 24 hrs, after glycerol injection, rats were sacrificed, cardiac blood was taken for renal function measurement, and renal tissues were removed for thiobarbituric acid MDA level assessment.Results: Our study revealed that glycerol administration significantly amplified renal tissue MDA, serum creatinine, and BUN (blood urea nitrogen) levels. However, NAC administration dampened the MDA increment and renal function deterioration (p&lt;0.05). Moreover, tissue MDA, BUN, and serum creatinine levels were significantly correlated to NAC dose (r=0.485; r=0.491; rs=0.544, respectively; all p&lt;0.05), indicating that NAC protection declines by dose increments.Conclusion: In this glycerol-induced acute kidney injury rat model, the administration of intravenous NAC 100 mg/kg reduced lipid peroxidation and improved renal function. Nevertheless, the protective effect was diminished in higher doses.

Electrogenic Staphylococcus epidermidis colonizes nasal cavities and alleviates IL-6 progression induced by the SARS2-CoV nucleocapsid protein.

Certain probiotic bacteria have been shown to possess an immunomodulatory effect and a protective effect on influenza infections. Using the Staphylococcus epidermidis K1 colonized mice model, we assessed the effect of nasal administration of glycerol or flavin mononucleotide (FMN) on the production of interleukin (IL)-6 mediated by the severe acute respiratory syndrome coronavirus 2 (SARS2-CoV) nucleocapsid protein (NPP). FMN, one of the key electron donors for the generation of electricity facilitated by S. epidermidis ATCC 12228, was detected in the glycerol fermentation medium. Compared to the S. epidermidis ATCC 12228, the S. epidermidis K1 isolate showed significant expression of the electron transfer genes, including pyruvate dehydrogenase (pdh), riboflavin kinase (rk), 1,4-dihydroxy-2-naphthoate octaprenyltransferase (menA), and type II NADH quinone oxidoreductase (ndh2). Institute of cancer research (ICR) mice were intranasally administered with S. epidermidis K1 with or without pretreatment with riboflavin kinase inhibitors, then nasally treated with glycerol or FMN before inoculating the NPP. Furthermore, J774A.1 macrophages were exposed to NPP serum and then treated with NPP of SARS2-CoV. The IL-6 levels in the bronchoalveolar lavage fluid (BALF) of mice and macrophages were quantified using a mouse IL-6 enzyme-linked immunosorbent assay kit. Here, we report that nasal administration of NPP strongly elevates IL-6 levels in both BALF and J774A.1 macrophages. It is worth noting that NPP-neutralizing antibodies can decrease IL-6 levels in macrophages. The nasal administration of glycerol or FMN to S. epidermidis K1-colonized mice results in a reduction of NPP-induced IL-6 production.

Protective effect of thymol on glycerol-induced acute kidney injury

Acute kidney injury (AKI) is a syndrome characterized by an accelerating decrease in renal function in a short time. Thymol is one of the main components of thyme species and has a variety of pharmacological effects. Here, we investigated whether thymol could ameliorate rhabdomyolysis (RM)-induced AKI and its related mechanism. Glycerol was used to induce RM-associated AKI in rats. Rats received thymol (20 mg/kg/day or 40 mg/kg/day) gavage 24 h before glycerol injection until 72 h after injection daily. Kidney injury was identified by measuring serum creatinine (Scr) and urea levels and by H&E and PAS staining and immunohistochemistry (the expression of proliferating cell nuclear antigen (PCNA)). Renal superoxide dismutase (SOD), malondialdehyde (MDA), and oxidative stress-related Nrf2/HO-1 signaling pathways were measured. The expression of the inflammatory markers TNF-α, IL-6, MCP-1, and NF-κB was assessed by ELISA and western blotting. Finally, the expression of the PI3K/Akt signaling pathway was detected by western blotting. Glycerol administration induced obvious renal histologic damage and increased Scr, urea, and PCNA expression. Notably, thymol treatment attenuated these structural and functional changes and prevented renal oxidative stress, inflammatory damage and PI3K/Akt pathway downregulation associated with glycerol-induced AKI. In conclusion, thymol might have potential applications in the amelioration of AKI via its antioxidant and anti-inflammatory effects and upregulation of the PI3K/Akt signaling pathway.

#4392 TWEAK/FN14 SYSTEM IS INVOLVED IN RHABDOMYOLYSIS-INDUCED ACUTE KIDNEY INJURY

Abstract Background and Aims Rhabdomyolysis is a pathological syndrome associated with massive and severe skeletal muscle injury. A common complication of rhabdomyolysis is acute kidney injury (AKI), a process that increases mortality of these patients. In rhabdomyolysis, myoglobin (Mb) is released from muscle cells and subsequently absorbed by the renal tubular epithelium causing a series of deleterious effects. TWEAK/Fn14 axis regulates renal inflammation and tubular cell death, pathogenic mechanisms involved in AKI. However, the role of this pathway in rhabdomyolysis-AKI has not been previously analyzed. In this study we analyzed the role of TWEAK/Fn14 axis in AKI associated with rhabdomyolysis and the AKI to chronic kidney disease (CKD) transition. Method We performed an experimental model of AKI associated to rhabdomyolysis by the intramuscular injection of 50% glycerol (10mg/Kg of weight) in Wild Type C57BL/6 (WT), TWEAK deficient (TWEAK -/-) and Fn14 deficient (Fn14 -/-) mice (male, 12 weeks old). In another set of experiments, C57BL/6 mice were intraperitoneally injected with anti-TWEAK mAb (10 mg/kg) or irrelevant isotype control IgG (10 mg/kg) every 48 hours. Blood and renal samples were taken 3 and 6 hours or 1, 3, 7 and 30 days after glycerol administration to perform gene expression studies by Real Time-PCR, immunohistochemistry analysis, protein expression studies by Western Blot and cell death assays (TUNEL). In vitro studies in murine tubular cells (MCTs) were also conducted to determine the effects of Mb on TWEAK/Fn14 expression, and the intracellular pathways involved in Mb-mediated regulation of TWEAK/Fn14 system. Results Fn14 renal expression was increased at earlier stages of rhabdomyolysis, correlating with decline of renal function. In MCTs cells, Mb induced Fn14 expression in a time- and dose-dependent manner, whereas TWEAK expression remained unchanged. The use of general antioxidants (N-Acetylcysteine) or Nrf2 inducers (curcumin or Sulforaphane) reduced Mb-mediated Fn14 upregulation in vivo and in cultured renal cells, whereas the opposite effect was observed with the HO-1 inhibitor tin protoporphyrin IX (SnPP). Furthermore, MAPK p38 and ERK1/2 inhibitors, such as SB203580 and PD98059 respectively, diminished Mb effects on Fn14 expression. Moreover, Mb enhanced pro-inflammatory effects of TWEAK in vitro. In the animal model, we observed that genetic TWEAK or Fn14 deficiency ameliorated rhabdomyolysis-related loss of renal function, reduced histological damage, tubular cell death, lipid peroxidation, and decreased the expression of inflammatory mediators (Ccl2, Tnf, Il6, Tlr4 and Ccl5), tubular injury markers (Havcr1 and Lcn2) and endothelial dysfunction (Edn1 and Icam1). TWEAK or Fn14 knockout mice also showed decreased long-term renal fibrosis (Collagen content and Fn1 expression) and inflammation (F4/80 macrophage infiltration and Ccl2 expression) 30 days after rhabdomyolysis induction. Treatment with a blocking anti-TWEAK monoclonal antibody reduced expression of Lcn2 and cell death at early stages of rhabdomyolysis and decreased long-term consequences, mainly fibrosis and inflammation. Conclusion Our data suggest that TWEAK/Fn14 axis is involved in AKI-rhabdomyolysis, as well as in the transition from AKI to CKD. TWEAK/Fn14 may be a potential therapeutic target to decrease harmful effects of rhabdomyolysis.

Administration of a single dose of lithium ameliorates rhabdomyolysis-associated acute kidney injury in rats.

Rhabdomyolysis is characterized by muscle damage and leads to acute kidney injury (AKI). Clinical and experimental studies suggest that glycogen synthase kinase 3β (GSK3β) inhibition protects against AKI basically through its critical role in tubular epithelial cell apoptosis, inflammation and fibrosis. Treatment with a single dose of lithium, an inhibitor of GSK3β, accelerated recovery of renal function in cisplatin and ischemic/reperfusion-induced AKI models. We aimed to evaluate the efficacy of a single dose of lithium in the treatment of rhabdomyolysis-induced AKI. Male Wistar rats were allocated to four groups: Sham, received saline 0.9% intraperitoneally (IP); lithium (Li), received a single IP injection of lithium chloride (LiCl) 80 mg/kg body weight (BW); glycerol (Gly), received a single dose of glycerol 50% 5 mL/kg BW intramuscular (IM); glycerol plus lithium (Gly+Li), received a single dose of glycerol 50% IM plus LiCl IP injected 2 hours after glycerol administration. After 24 hours, we performed inulin clearance experiments and collected blood / kidney / muscle samples. Gly rats exhibited renal function impairment accompanied by kidney injury, inflammation and alterations in signaling pathways for apoptosis and redox state balance. Gly+Li rats showed a remarkable improvement in renal function as well as kidney injury score, diminished CPK levels and an overstated decrease of renal and muscle GSK3β protein expression. Furthermore, administration of lithium lowered the amount of macrophage infiltrate, reduced NFκB and caspase renal protein expression and increased the antioxidant component MnSOD. Lithium treatment attenuated renal dysfunction in rhabdomyolysis-associated AKI by improving inulin clearance and reducing CPK levels, inflammation, apoptosis and oxidative stress. These therapeutic effects were due to the inhibition of GSK3β and possibly associated with a decrease in muscle injury.

PS-R06-1: A CASE OF PATIENT WITH END-STAGE KIDNEY DISEASE INTRODUCED HEMODIALYSIS AFTER CEREBRAL HEMORRHAGE.

A 46-year-old male had been treated for end-stage kidney disease due to diabetic nephropathy and adaptive FSGS, and underwent surgery of arteriovenous fistula 3 weeks before the admission. He was scheduled to be introduced hemodialysis, but was urgently hospitalized due to cerebral hemorrhage. The head CT scan showed a subcutaneous hematoma of about 45 ml in the left frontal lobe, and the patient had impaired consciousness and worsening respiratory status. There were no surgical indications for cerebral hemorrhage, we initiated blood pressure control with nicardipine. Hyperkalemia was also seen, but urgent dialysis was not necessary, and we planned to introduce dialysis the next day or later. The next day hemodialysis was introduced, but soon after hemodialysis completed, worsening of respiratory condition and dilated pupil were observed. The head CT scan showed worsening cerebral edema compared to pre-dialysis CT scan on the same day. Thereafter, respiratory and general condition did not improve, and he died 11 days after the admission. It is recommended that dialysis should be avoided within 24 hours of the onset of cerebral hemorrhage because of the high risk of hematoma expansion. In addition, in the acute phase of cerebral hemorrhage, it is considered to choose a dialysis method that causes less intracranial pressure increase, such as peritoneal dialysis or continuous hemodiafiltration dialysis, if possible. Administration of hypertonic glycerol may also be helpful. When a patient with end-stage kidney disease is introduced hemodialysis soon after cerebral hemorrhage, control of blood and intracranial pressure should be cared.

GLYCEROL TOXICITY AND QUALITY OF FROZEN-THAWED BALI CATTLE SPERMATOZOAS

&#x0D; &#x0D; &#x0D; This study aimed to determine the effect of glycerol concentration on motility, viability and abnormalities of frozen thawed spermatozoa of Bali cattle. The study was conducted using a completely randomized design with 5 treatments and 6 replications. The treatments consisted of T0 (0% glycerol), T1 (6% glycerol), T2 (12% glycerol), T3 (18% glycerol), P4 (24% glycerol). The results showed that the administration of glycerol had a very significant effect (p&lt;0.01) on the motility, viability, and abnormality of spermatozoa. Six percent glycerol in diluent able to reduce the decrease in motility, viability. and prevent the increase of spermatozoa abnormality. Toxic effects of glycerol were higher in accordance to higher concentration started in 12%.&#x0D; &#x0D; &#x0D;

Optimization and Validation of Glycerol-induced Acute Renal Failure Model in Rats in Predicting the Pharmacokinetics in Patients with Acute Renal Failure

The study standardized the glycerol induced (intra-peritoneal and intra-muscular) acute renal failure (ARF) models in Sprague-Dawley rats and validated its potential to predict the change in pharmacokinetics of the selected probe drugs in renal impairment. We assessed the induction of ARF by measuring the serum creatinine and blood-urea-nitrogen (BUN) levels at different time points (baseline, 6 h, 12 h, 24 h, 48 h and 72 h). Glycerol administrations via both intra-peritoneal and intra-muscular routes caused a significant increase in serum creatinine and BUN levels in rats at 6 h; however, the levels decreased within 24 h with intra-peritoneal administration. In contrast, with intra-muscular administration, a sustained increase in serum creatinine and BUN levels was observed up to 72 h post glycerol treatment demonstrating a sustained ARF like condition in rats that was suitable to evaluate the pharmacokinetics of drugs. Therefore, intra-muscular glycerol administration model was used to evaluate the pharmacokinetics of selected probe drugs including metformin, digoxin, atorvastatin and linezolid. The pharmacokinetics of metformin and digoxin were significantly altered in ARF versus control rats with increase in plasma exposure, prolonged elimination half-life and decreased systemic clearance. However, the pharmacokinetics of atorvastatin and linezolid did not show significant differences between ARF and control rats. These results demonstrated the utility of the ARF model in rats in predicting pharmacokinetic changes in patients with renal impairment. Such models may prove useful in early discovery work to screen and prioritize compounds requiring dose adjustment in patients with renal impairment.

Formulation Development and Evaluation of a Novel Emulsion Composition Embracing Aspirin and Glycerol in the Treatment of Ischemic Stroke

An ischemic stroke occurs when the blood supply to part of the brain is interrupted or reduced, preventing brain tissue from getting oxygen and nutrients. Brain cells begin to die in minutes. Ischemic stroke can be treated by using Antiplatelet drug such as aspirin as an immediate treatment which may prevent blood clots and improve recovery after stroke. Glycerol is also used as it decreases the edema in ischemic stroke. The aim of the present investigation is to develop a novel formulation of oil in Glycerol emulsion comprising aspirin in the treatment of ischemic stroke and in vitro evaluation. The oil in glycerol emulsion was prepared by high shear homogenization and prepared emulsions were evaluated for particle size, drug content, in vitro drug release and stability. Based on log P values of aspirin, olive oil is selected as oil phase and tween 80 was used as emulsifying agent. Total 10 formulations F1to F10 were prepared and among these, in F1-F6 phase separation was observed within 24 hrs whereas F8 to F10 were stable for one week and later creaming was observed and it is re-dispersible. The particle size was determined by optical microscopy and the average particle size for F8, F9 and F10 were 6.04, 3.38 and 7.8 µm respectively. Drug content was determined as 68±3.95%,108±5.816%, 103±4.61% respectively in compositions F8, F9 and F10. Rate of drug release followed first order kinetics and an immediate burst release effect was observed within 15 minutes. It is concluded that olive oil and glycerol emulsions containing aspirin is prepared successfully and evaluated. It is a promising formulation approach for co administration of aspirin and glycerol in the treatment of ischemic stroke. The formulations were physically and chemically stable. In vivo application of this formulation will be done in suitable animal models in future.

A randomized clinical trial evaluating the effect of empagliflozin on triglycerides in obese adults: Role of visceral fat

BackgroundEmpagliflozin, a sodium glucose cotransporter 2 inhibitor, is a medication to treat type 2 diabetes. The effect of empagliflozin in persons without diabetes has received less attention. Here we conducted a randomized, double-blind placebo-controlled clinical trial to examine the effect of empagliflozin on plasma triglycerides in obese non-diabetic adults. MethodsParticipants (n = 35; BMI ≥ 30 kg/m2) underwent body composition assessments using MRI, and were randomly assigned to either placebo or empagliflozin (10 mg/d) for three months. At the baseline and post-treatment visit, after an overnight fast, blood was drawn for biochemical analysis. Participants received [U–13C3]glycerol orally followed by multiple blood draws over 3 h to examine glycerol incorporation into triglycerides using NMR spectroscopy. ResultsThe changes in blood triglyceride concentration with empagliflozin therapy related to the mass of baseline visceral adipose tissue (VAT; r = 0.53, p = 0.04). Empagliflozin slightly lowered triglycerides in obese subjects with low VAT, but increased triglycerides in the subjects with high VAT. Consistently, empagliflozin effectively suppressed triglyceride synthesis following [U–13C3]glycerol administration in the subjects with low VAT (p < 0.05), but not in the subjects with high VAT. The subjects with high VAT lost body weight after three months of empagliflozin treatment. In all subjects, about 20% of the triglyceride backbone originated from mitochondrial metabolism of glycerol. ConclusionsThe effect of empagliflozin on triglycerides in obese adults differed depending on VAT. Empagliflozin suppressed triglyceride synthesis in the subjects with low VAT, but tended to increase triglycerides in those with high VAT.

Effect of Glycerol Administration on ECochG and VEMP Findings in Individual with Meniere's Disease.

The present study aimed to find the effect of glycerol administration on Electrocochleography (ECochG), cervical and ocular Vestibular Evoked Myogenic Potential (c-VEMP, o-VEMP) findings in individual with Meniere's disease. Sixteen participants (32 ears) diagnosed with Meniere's disease underwent ECochG, c-VEMP and o-VEMP for both pre and 1h post-glycerol administration. Paired t-test indicated that the SP/AP ratio of ECochG measures was significantly improved with post-glycerol administration. There was no significant difference in the mean amplitude of o-VEMP and c-VEMP between pre and post-glycerol administration. However, while individual differences were compared, 75% of the participants reported either improvement in c-VEMP amplitude or newly emerging c-VEMP& o-VEMP. Based on the recommendation by Adams et al. (Otolaryngol Clin North Am 43(5):995-1009, 2010), the improvement on these tests results with post glycerol administration were considered as a significant indicator for the presence of Meniere's disease.With post glycerol administration, the present study found that 84%of participants were found to have an improvement in the amplitude for ECochG measures. There was an improvement in the amplitude measures of o-VEMP and c-VEMP, which were observed in 75% and 68%of participants respectively with post-glycerol administration. Improvement in the amplitude of test measures with post-glycerol administration were observed to be more for cochlear potentials of ECochG followed by vestibular potentials of c-VEMP and o-VEMP. Thus, improvement of ECochG amplitude with post-glycerol administration might serve as an additional indicator for the presence of Meniere's disease.

Gluconeogenesis is reduced from alanine, lactate and pyruvate, but maintained from glycerol, in liver perfusion of rats with early and late sepsis.

Sepsis induces several metabolic abnormalities, including hypoglycaemia in the most advanced stage of the disease, a risk factor for complications and death. Although hypoglycaemia can be caused by inhibition of hepatic gluconeogenesis, decreased and increased gluconeogenesis were reported in sepsis. Furthermore, gluconeogenesis from glycerol was not yet evaluated in this disease. The main purpose of this study was to investigate the gluconeogenesis from alanine, lactate, pyruvate and glycerol in rats with early (8 hours) and late (18 hours) sepsis. Parameters related to the characterization of sepsis were also evaluated. Sepsis was induced by cecal ligation and puncture and gluconeogenesis was assessed in liver perfusion. Rats with early and late sepsis showed increased lactataemia, depletion of liver glycogen and peripheral insulin resistance, characterizing the establishment of sepsis. Rats with early and late sepsis showed decreased gluconeogenesis from alanine, lactate and pyruvate. Interestingly, gluconeogenesis from glycerol, a precursor that enters in the pathway at a later step, subsequent to the entry of alanine, lactate and pyruvate, was maintained in rats with early and late sepsis. In conclusion, gluconeogenesis is decreased from alanine, lactate and pyruvate, but maintained from glycerol, in liver perfusion of rats with early and late sepsis. SIGNIFICANCE OF THE STUDY: The maintenance of gluconeogenesis from glycerol, but not from alanine, lactate and pyruvate, together with the liver glycogen depletion, points the glycerol as an important precursor for the maintenance of glycaemic homeostasis in sepsis. The findings open the possibility of further investigation on the administration of glycerol in the treatment of hypoglycaemia associated with more advanced sepsis.

Valproate attenuates hypertonic glycerol-induced rhabdomyolysis and acute kidney injury

Background and aimThe current study investigated the effects of treatment with 300 mg/kg valproic acid on rhabdomyolysis and acute kidney injury induced by intramuscular injection of hypertonic glycerol in rats. MethodsFour groups of male wistar rats: control and hypertonic glycerol, valproic acid and valproic acid + hypertonic glycerol treated groups were used. Blood urea nitrogen, serum creatinine, creatinine kinase (CK) and CK MB, myoglobin and renal reduced glutathione (GSH) levels were measured. Histopathological examination of the kidneys was carried out to evaluate the degree of renal injury in each group. The expression of interleukin-1 beta “IL-1β” in renal tissue was detected using immunohistochemistry. ResultsHypertonic glycerol administration led to severe renal tubular damage with a significant elevation of blood urea nitrogen, serum creatinine, creatinine kinase, CK MB and myoglobin levels and overexpression of IL-1β compared to control group. Valproic acid administration attenuated both the muscle injury and the acute kidney injury induced by hypertonic glycerol, estimated through a significant reduction of creatinine kinase, myoglobin, and serum creatinine. Valproic acid administration caused a significant increase in GSH in the hypertonic glycerol + valproic acid group compared to the hypertonic glycerol group. A significant decrease in tubular necrosis grade, and expression of IL-1β in hypertonic glycerol + valproic acid group compared to the hypertonic glycerol group was observed. ConclusionThis study demonstrates, for the first time to the best of our knowledge, that valproic acid could ameliorate the rhabdomyolysis and the related acute kidney injury in rats.

Ameliorative Role of Diallyl Disulfide Against Glycerol-induced Nephrotoxicity in Rats

ABSTRACTIntroduction:This study investigated the role of diallyl disulfide (DADS) against glycerol-induced nephrotoxicity in rats. Moreover, the role of peroxisome proliferator activated receptor-γ (PPAR-γ) in DADS-mediated renoprotection has been explored.Materials and Methods:Male Wistar albino rats were challenged with glycerol (50% w/v, 8 mL/kg intramuscular) to induce nephrotoxicity. Kidney injury was quantified by measuring serum creatinine, creatinine clearance, urea, potassium, fractional excretion of sodium, and microproteinuria in rats. Renal oxidative stress was measured in terms of thiobarbituric acid reactive substances, superoxide anion generation, and reduced glutathione levels. Hematoxylin–eosin (H&E) and periodic acid Schiff staining of renal samples was done to show histological changes. Glycerol-induced muscle damage was quantified by assaying creatine kinase (CK) levels in rat serum.Results:Administration of glycerol resulted in muscle damage as reflected by significant rise in CK levels in rats. Glycerol intoxication led kidney damage was reflected by significant change in renal biochemical parameters, renal oxidative stress and histological changes in rat kidneys. Administration of DADS attenuated glycerol-induced renal damage. Notably, pretreatment with bisphenol A diglycidyl ether, a PPAR-γ antagonist, abolished DADS renoprotection in rats.Conclusion:We conclude that DADS affords protection against glycerol-induced renal damage in rats. Moreover, PPAR-γ plays a key role in DADS-mediated renoprotective effect.

Optical clearing of living brains with MAGICAL to extend i nvivo imaging.

SummaryTo understand brain functions, it is important to observe directly how multiple neural circuits are performing in living brains. However, due to tissue opaqueness, observable depth and spatiotemporal resolution are severely degraded in vivo. Here, we propose an optical brain clearing method for in vivo fluorescence microscopy, termed MAGICAL (magical additive glycerol improves clear alive luminance). MAGICAL enabled two-photon microscopy to capture vivid images with fast speed, at cortical layer V and hippocampal CA1 in vivo. Moreover, MAGICAL promoted conventional confocal microscopy to visualize finer neuronal structures including synaptic boutons and spines in unprecedented deep regions, without intensive illumination leading to phototoxic effects. Fluorescence emission spectrum transmissive analysis showed that MAGICAL improved in vivo transmittance of shorter wavelength light, which is vulnerable to optical scattering, thus unsuited for in vivo microscopy. These results suggest that MAGICAL would transparentize living brains via scattering reduction.

The study of the prooxidant-antioxidant equilibrium in the kidney tissue and blood on the background of ceruloplasmin administration under the conditions of acute kidney injury

Acute kidney injury (AKI) remains a relevant medical problem. The promising direction of the AKI treatment is the use of the antioxidants that inhibit free radical processes and prevent the destruction of cell membranes within pathological processes. Ceruloplasmin (CP) is the main antioxidant of blood plasma, that demonstrates membrane protecting effects and antitoxic activity.The aim of the study was to establish the influence of a single-dose administration of ceruloplasmin on the processes of the peroxidation in the kidney tissue and blood under the conditions of acute kidney injury.Materials and methods. The influence of ceruloplasmin on the prooxidant-antioxidant equilibrium in the kidney tissue and blood was studied in an experiment on white non-line rats under the conditions of rhabdomyolysis-induced acute kidney injury. The acute kidney injury was modeled by intramuscular administration of 50% glycerol solution at a dose of 8 mg/kg. Ceruloplasmin was administered intraperitoneally at a dose of 7 mg/kg/day. The level of main indicators of prooxidant-antioxidant balance in blood and kidney tissue was determined in 24 h after glycerol administration for induction of acute kidney injury.Research results and their discussion. There was a deep disruption of the prooxidant-antioxidant equilibrium as a result of the acute kidney injury. AKI causes an activation of the prooxidant processes by increasing the level of the malonic dialdehyde and the oxidized proteins in the kidney tissue and blood. AKI also reduces the antioxidant protection by decreasing the activity of the antioxidant enzymes in the kidneys and blood plasma.A single-dose administration of ceruloplasmin improved antioxidant protection and reduced peroxidation of lipids and proteins. There was a decrease in levels of malondialdehyde and oxidative modification of proteins. At the same time, the antioxidant protection intensified due to an increase in the activity of glutathione peroxidase and catalase in the kidneys and blood plasma.Conclusions. A single administration of ceruloplasmin influences prooxidant-antioxidant balance, reducing the content of lipid and protein peroxidation products and increasing the activity of antioxidant enzymes.