Effects of Highly Oxygenated Water in a Hyperuricemia Rat Model

Recent years have seen a rapidly rising number of oxygenated water brands that claim to impart health benefits and increase athletic performance by improving oxygen availability in the body. Drinks with higher dissolved oxygen concentrations have in recent times gained popularity as potential ergogenic aids, despite the lack of evidence regarding their efficacy. The aim of this study was to characterize oxygenated water and assess the improvement in uric acid metabolism while identifying performance enhancements in animals administered oxygenated water. Oxygenated water was characterized by hydrogen and oxygen nuclear magnetic resonance (NMR) spectroscopy. Hyperuricemia in rats was induced by treatment with oxonic acid potassium salt, and the animals were given oxygenated drinking water before, during, or after oxonic acid treatment. Serum uric acid was measured to confirm the effects on uric acid metabolism. Following oxygenation, the full width at half maximum (FWHM) was reduced to 11.56 Hz and 64.16 Hz in the hydrogen and oxygen NMR spectra, respectively. Oxygenated water molecule clusters were reduced in size due to the reduction in FWHM. Oxygen concentration did not vary significantly with increased temperature. However, standing time played a critical role in the amount of oxygen dissolved in the water. The rat studies indicated that oxygenated water reduced serum uric acid levels and their rate of increase and enhanced uric acid metabolism. A significant improvement in uric acid metabolism and rate of increase in serum uric acid concentration was observed in hyperuricemic rats administered oxygenated water compared to that in rats administered regular water. High oxygen concentrations enhanced the rate of oxygen absorption, leading to increased glycolysis and mitochondrial protein synthesis. Therefore, oxygenated water is a potential adjuvant therapy or health food for treatment of hyperuricemia.

Metabolic Acidosis Alters Expression of Slc22 Transporters in Mouse Kidney

Introduction: The kidneys play a central role in eliminating metabolic waste products and drugs through transporter-mediated excretion along the proximal tubule. This task is mostly achieved through a variety of transporters from the solute carrier family 22 (SLC22) family of organic cation and anion transporters. Metabolic acidosis modulates metabolic and renal functions and also affects the clearance of metabolites and drugs from the body. We had previously shown that induction of metabolic acidosis in mice alters a large set of transcripts, among them also many transporters including transporters from the Slc22 family. Objective: Here we further investigated the impact of acidosis on Slc22 family members. Methods: Metabolic acidosis was induced for 2 or 7 days with NH4Cl, some animals also received the uricase inhibitor oxonic acid for comparison. Expression of transporters was studied by qPCR and immunoblotting. Results: NH4Cl induced no significant changes in plasma or urine uric acid levels but caused downregulation of Slc22a1 (Oct1), Slc22a6 (Oat1), Slc22a19 (Oat5), and ­Slc22a12 (Urat1) at mRNA level. In contrast, Slc22a4 mRNA (Octn1) was upregulated. On protein level, NH4Cl increased Octn1 (after 7 days) and Urat1 (after 2 days) abundance and decreased Oat1 (after 2 days) and Urat1 (after 7 days). Oxonic acid had no impact on protein abundance of any of the transporters tested. Conclusion: In summary, metabolic acidosis alters expression of several transporters involved in renal excretion of metabolic waste products and drugs. This may have implications for drug kinetics and clearance of waste metabolites.

STUDY OF Coleus amboinicus STEM EXTRACT IN INHIBITING MACROPHAGE CD-68 EXPRESSION IN WISTAR RATS WITH URIC ACID-INDUCED NEPHROPATHY

The purpose of this study was to evaluate effect of Coleus amboinicus (CA) stem extracts on uric acid-induced nephropathy by comparingthe levels of Macrophage CD-68 expression and concentration of serum Cystatine C (CYS C ) in Wistar rats. Twenty-four male Wistar rats(Rattus norvegicus) with a body weight (bw) of 200-250 g, were allocated into three groups, with eight animals per group. The rats in controlgroup (PO) received 0.1% carboxymethyl cellulose (CMC) solution orally The rats in group 2 (P1) were orally induced with uric acid (UA) (500mg/kg) and oxonic acid (OA) (750 mg/kg.) and the rats in group 3 (P2) received uric acid (500 mg/kg), oxonic acid (750 mg/kg), and 500 mg/kgof the CA stem extracts for 35 days. Bloods were collected for analysis of serum CYS C expression and concentration of serum creatinine andblood nitrogen urea (BUN). The rats in all groups were sacrificed for kidney tissue extractions for macrophage CD-68 identification andhistopathology analysis. The levels of CYS C concentrations were analyzed by Avidin-Horseradish Peroxidase (HRP) Sandwich-ELISA. Theresults showed that Coleus amboinicus stem extract at dose of 500 mg/kg bw can significantly reduce BUN and creatinine levels (P≤0.05), whileCys C levels were not different. In the treatment group (P2) compared with group (P1). CD-68 (ED-1) macrophage activity decreasedsignificantly (P≤0.05) in the treatment group (P2) compared to the control group and (P1). Nephrophaty induction using UA and OA causessevere kidney lesions characterized by degeneration, necrosis and inflammation of the renal tubules and glomerulus in the treatment group.

Cardiometabolic Changes in Different Gonadal Female States Caused by Mild Hyperuricemia and Exposure to a High-Fructose Diet

Background. The objective of this study is to observe if mild hyperuricemia and a high-fructose diet influence the cardiovascular and metabolic systems in hypogonadic female Wistar rats compared to normogonadic female rats. Methods. Fifty-six (56) adult female Wistar rats were used in the present work. Animals were divided into two groups: normogonadic (NGN) and hypogonadic (HGN). These groups were also divided into four subgroups in accordance with the treatment: control with only water (C), fructose (F), oxonic acid (OA), and fructose + oxonic acid (FOA). Lipid profile, glycemia, uric acid, and creatinine determinations were assessed. Cardiovascular changes were evaluated by measuring blood pressure, myocyte volume, fibrosis, and intima-media aortic thickness. Results. HGN rats had higher levels of total cholesterol (TC) (p<0.01) and noHDLc (p<0.01), in addition to higher levels of uric acid (p<0.05). The OA group significantly increased myocyte volume (p<0.0001) and the percentage of fibrosis as well as the group receiving FOA (p<0.001) in both gonadal conditions, being greater in the HGN group. Hypogonadic animals presented a worse lipid profile. Conclusion. Mild hyperuricemia produces hypertension together with changes in the cardiac hypertrophy, fibrosis, and increased thickness of the intima media in hypogonadic rats fed high-fructose diet.

Influence of Normo- and Hypogonadal Condition, Hyperuricemia, and High-Fructose Diet on Renal Changes in Male Rats

Background. There is a gender disparity in the incidence, prevalence, and progression of renal disease. The object of this paper is to evaluate the presence and type of renal lesion in normogonadic and hypogonadic male rats in a mild hyperuricemia induced condition and exposed to a high-fructose diet. Methods. 56 adult male Wistar rats were used. Animals were divided into two groups, one normogonadic (NGN) and one hypogonadic (HGN), and each group was divided into four subgroups in accordance with the treatment: control with only water (C), fructose (F), oxonic acid (OA), and fructose + oxonic acid (FOA). Renal changes were evaluated by measuring glomerulosclerosis, fibrosis, and arteriolar media/lumen (M/L) ratio.Results. The OA and FOA groups presented significantly hypertension (p<0.001). The OA group significantly increased (p<0.05) the percentage of glomerulosclerosis as well as the FOA group (p<0.001). When comparing NGN versus HGN, we observed a trend to a lower glomerulosclerosis in the latter. A higher arteriolar M/L ratio was observed in the OA (p<0.05) and FOA (p<0.001). Conclusion. Hyperuricemia conditions and a high-fructose diet favor blood pressure increase together with changes in the arteriolar media/lumen ratio and renal glomerular damage. These changes were more apparent in normogonadic animals.

Podocyte Injury and Albuminuria in Experimental Hyperuricemic Model Rats

Although hyperuricemia is shown to accelerate chronic kidney disease, the mechanisms remain unclear. Accumulating studies also indicate that uric acid has both pro- and antioxidant properties. We postulated that hyperuricemia impairs the function of glomerular podocytes, resulting in albuminuria. Hyperuricemic model was induced by oral administration of 2% oxonic acid, a uricase inhibitor. Oxonic acid caused a twofold increase in serum uric acid levels at 8 weeks when compared to control animals. Hyperuricemia in this model was associated with the increase in blood pressure and the wall-thickening of afferent arterioles as well as arcuate arteries. Notably, hyperuricemic rats showed significant albuminuria, and the podocyte injury marker, desmin, was upregulated in the glomeruli. Conversely, podocin, the key component of podocyte slit diaphragm, was downregulated. Structural analysis using transmission electron microscopy confirmed podocyte injury in this model. We found that urinary 8-hydroxy-2′-deoxyguanosine levels were significantly increased and correlated with albuminuria and podocytopathy. Interestingly, although the superoxide dismutase mimetic, tempol, ameliorated the vascular changes and the hypertension, it failed to reduce albuminuria, suggesting that vascular remodeling and podocyte injury in this model are mediated through different mechanisms. In conclusion, vasculopathy and podocytopathy may distinctly contribute to the kidney injury in a hyperuricemic state.

Impact of elevated uric acid on ventricular remodeling in infarcted rats with experimental hyperuricemia

Hyperuricemia is associated with cardiovascular disease, but it is usually considered a marker rather than a risk factor. Previous studies using uric acid-lowering drugs in normouricemic animals are not suitable to answer the effect of hyperuricemia on ventricular remodeling after myocardial infarction. The purpose of this study was to determine whether hyperuricemia adversely affects ventricular remodeling in infarcted rats with elevated uric acid. Male Wistar rats aged 8 wk were randomly assigned into either vehicle, oxonic acid, oxonic acid + allopurinol, oxonic acid + benzbromarone, oxonic acid + ABT-627, or oxonic acid + tempol for 4 wk starting 24 h after ligation. Postinfarction was associated with increased oxidant production, as measured by myocardial superoxide, isoprostane, xanthine oxidase activity, and dihydroethidium staining. Compared with normouricemic infarcted rats, hyperuricemic infarcted rats had a significant increase of superoxide production (1.7×) and endothelin-1 protein (1.2×) and mRNA (1.4×) expression, which was associated with increased left ventricular dysfunction and enhanced myocardial hypertrophy and fibrosis. These changes were all prevented by treatment with allopurinol. For similar levels of urate lowering, the uricosuric agent benzbromarone had no effect on ventricular remodeling. In spite of equivalent hyperuricemia, the ability of both ABT-627 and tempol to attenuate ventricular remodeling suggested involvement of endothelin-1 and redox pathways. Hyperuricemia is associated with unfavorable ventricular remodeling probably through a superoxide and endothelin-1-dependent pathway. Uric acid lowering without inhibition of superoxide and endothelin-1 may not have an effect on remodeling. Chronic administration of allopurinol, ABT-627, and tempol is associated with attenuated ventricular remodeling.