Inosine induces acute hyperuricaemia in rhesus monkey (Macaca mulatta) as a potential disease animal model.

CONTEXT: The uric acid metabolism pathway is more similar in primates and humans than in rodents. However, there are no reports of using primates to establish animal models of hyperuricaemia (HUA). OBJECTIVES: To establish an animal model highly related to HUA in humans. MATERIALS AND METHODS: Inosine (75, 100 and 200 mg/kg) was intraperitoneally administered to adult male rhesus monkeys (n = 5/group). Blood samples were collected over 8 h, and serum uric acid (SUA) level was determined using commercial assay kits. XO and PNP expression in the liver and URAT1, OAT4 and ABCG2 expression in the kidneys were examined by qPCR and Western blotting to assess the effects of inosine on purine and uric acid metabolism. The validity of the acute HUA model was assessed using ulodesine, allopurinol and febuxostat. RESULTS: Inosine (200 mg/kg) effectively increased the SUA level in rhesus monkeys from 51.77 ± 14.48 at 0 h to 178.32 ± 14.47 µmol/L within 30 min and to peak levels (201.41 ± 42.73 µmol/L) at 1 h. PNP mRNA level was increased, whereas XO mRNA and protein levels in the liver were decreased by the inosine group compared with those in the control group. No changes in mRNA and protein levels of the renal uric acid transporter were observed. Ulodesine, allopurinol and febuxostat eliminated the inosine-induced elevation in SUA in tested monkeys. CONCLUSIONS: An acute HUA animal model with high reproducibility was induced; it can be applied to evaluate new anti-HUA drugs in vivo and explore the disease pathogenesis.

Treatment of two mitochondrial disease patients with a combination of febuxostat and inosine that enhances cellular ATP.

Since mitochondria are energy-generating micro-organisms, most of the disorders in patients with mitochondrial diseases (mt-disease) are considered secondary to defects in ATP synthesis, although some other factors such as reactive oxygen species may be involved. A simultaneous oral administration of febuxostat and inosine was reported to elevate both hypoxanthine and ATP levels in peripheral blood. Based on those results, we attempted co-administration of febuxostat and inosine in two patients with mitochondrial disease: one patient with mitochondrial cardiomyopathy and the other patient with mitochondrial diabetes. In the former case, brain natriuretic peptide (BNP), which is a specific marker for heart failure, was decreased by 31%, and in the latter case, the insulinogenic index increased 3.1 times, suggesting the favorable action of the treatment. Considering that there is no effective treatment available for this disorder, the present therapy may be quite useful for the management of patients with mitochondrial diseases.

Influence of dietary inosine and vitamin C supplementation on growth, blood chemistry, oxidative stress, innate and adaptive immune responses of red sea bream, Pagrus major juvenile.

Both inosine (INO) and vitamin C (l-ascorbic acid, AsA) play important roles in growth performance, feed utilization and health status of fish. Therefore, a 56 days feeding trial was conducted to determine the interactive effects of dietary INO and AsA on growth performance, oxidative status, innate and adaptive immune responses of red sea bream. Fish growth performance and fed utilization parameters were significantly affected by dietary INO supplementation but not by AsA. Fish fed diets with INO at 4 g kg-1 diet in combination of high and low levels of AsA (3.1 g kg-1 and 9.3 g kg-1) produced the highest growth and feed utilization performances. In terms of growth and feed utilization performances no significant interaction effects were observed between INO and AsA. Dietary INO significantly influenced hematocrit, glucose and glutamyl oxaloacetic transaminase (GOT) content of red sea bream meanwhile AsA also significantly influenced hematocrit, glucose, total cholesterol, blood urea nitrogen (BUN) and glutamic-pyruvate transaminase (GPT) content of the test fish. No significant interaction effects was also observed between INO and AsA on measured hematological parameters. Reactive oxygen metabolites (d-ROMs) significantly influenced by both INO and AsA. Fish fed diet groups D1, D4 and D6 showed best oxidative stress resistance. Only INO was a significant factor on nitro-blue-tetrazolium activity (NBT) and bactericidal activity (BA). Neither INO nor AsA was a significant factor on serum catalase activity (CAT), total serum protein (TSP), peroxidase activity (PA) and lysozyme activity (LA). No significant interaction effects was observed between INO and AsA on measured innate immune parameters. Agglutination antibody titer was significantly influenced by dietary supplementation, after 15 days of vaccination but not in 21 days. In the day 15th fish and diet group D3 and D5 showed significantly higher values compared to diet groups control and D1. INO was the only significant factor of increasing agglutination antibody titer in 15 t h day. While AsA was not a significant factor on agglutination antibody titer values in day 15 t h, there was an interaction between dietary INO and AsA levels. Finally under the experimental conditions, fish fed high INO and low AsA levels (4 g kg-1 and 0.31 g kg-1 diet, respectively) showed best growth and feed utilization performance. Simultaneously, low level of INO and high level of AsA (2 g kg-1 and 0.93 g kg-1 diet, respectively) improved blood chemistry and immunological parameters. Furthermore, combined use of INO and AsA is possible to improve hemato-immunological responses of red sea bream.

Oral Inosine Persistently Elevates Plasma antioxidant capacity in Parkinson's disease.

INTRODUCTION: Higher serum urate predicts slower progression in PD. The aim of this work was to assess whether oral inosine alters antioxidant capacity of plasma or CSF or urinary markers of oxidative injury in early PD. METHODS: We assayed plasma and CSF antioxidant capacity by ferric-reducing antioxidant power and measured DNA oxidation adduct 8-hydroxydeoxyguanosine from urine in Safety of URate Elevation in PD, a randomized, placebo-controlled trial of oral inosine assessing safety of elevating serum urate from <6 mg/dL to 6.1-7.0 or 7.1-8.0 mg/dL in patients with early PD. RESULTS: At 6 months, antioxidant capacity was 29% higher among mild and 43% higher among moderate group participants compared to placebo and correlated with change in serum urate (r = 0.86) and inversely with rate of clinical decline (r = -0.26). CSF antioxidant capacity and urine 8-hydroxydeoxyguanosine did not differ. CONCLUSIONS: The findings demonstrate a dose-dependent, persistent elevation of plasma antioxidant capacity from oral inosine of potential therapeutic relevance.

Associated Inosine to interferon: results of a clinical trial in multiple sclerosis.

BACKGROUND: Uric acid (UA) could act as a natural peroxynitrite scavenger with antioxidant properties. It has been proposed that hyperuricemia might protect against multiple sclerosis (MS). METHODS: Patients with relapsing-remitting MS starting treatment with interferon beta-1a 44 µg sc 3/week were randomly assigned to receive either inosine 3 g/day or placebo in a double-blind manner. Follow-up was 12 months. Outcome measures were adverse events and UA laboratory results. Secondary end point was clinical and radiological activity of MS. Relapse rates, percentage of patients without relapses, and progression to secondary MS (SPMS) were assessed. RESULTS: Thirty six patients were included. Two patients in the inosine group showed UA serum level above 10 mg/ml, and symptoms derived from renal colic not leading to hospital admission. Ten additional patients had asymptomatic hyperuricemia (>7 mg). Efficacy parameters (clinical and radiological) were similar between groups. No patient progressed to SPMS CONCLUSIONS: Inosine administration was associated with hyperuricemia and renal colic with no additional effect on MS. We cannot conclude inosine is a safe and well-tolerated drug. Doses of around 2 g/day may be more appropriate for future trials.

Preventive use of hepatoprotectors yields limited efficacy on the liver toxicity of anti-tuberculosis agents in a large cohort of Chinese patients.

BACKGROUND AND AIMS: We aimed to explore the effectiveness of preventive usage of hepatoprotectors in patients with tuberculosis (TB) receiving anti-TB treatment. METHODS: With stratified cluster sampling strategy, a prospective cohort with 4488 sputum smears positive pulmonary TB patients was established from 52 counties of four regions in China. During anti-TB treatment, prescriptions of hepatoprotectors were documented in detail, and liver enzymes were routinely monitored. Anti-TB drug-induced liver injury (ATLI) was assessed based on liver enzymes following the criteria of American Thoracic Society. The incidence of ATLI between the preventive usage group and reference group was compared by propensity score adjusted Cox proportional hazard analysis. Preexisting diseases, history of liver disease, hepatitis B surface antigen status, primary/re-treatment of TB, income per year, and liver enzymes before anti-TB treatment were included in the propensity score model. RESULTS: After 6-9 months of follow-up and monitoring, 4304 patients sustained in our cohort. Two thousand seven hundred fifty-two (63.9%) patients preventively took hepatoprotectors with a median course of 183 days. Most frequently used drugs were Hu Gan Pian, silymarin, glucurone, and inosine. Two thousand one hundred forty-four (77.9%) patients took those drugs more than 6 months. Sixty-nine (2.4%) patients of preventive usage group and 37 (2.5%) of reference group experienced ATLI, respectively. Statistical significances were not found by propensity score analysis for the association between using hepatoprotectors (hazard ratio[HR] = 0.99, 95% confidence interval [CI]: 0.65-1.52), using hepatoprotectors in the whole course (HR = 0.94, 95% CI: 0.60-1.48), using Hu Gan Pians, silymarin, glucurone, and inosine with ATLI occurrence. CONCLUSIONS: No preventive effect of hepatoprotectors was observed in patients receiving anti-TB treatment.

Oral administration of inosine promotes recovery after experimental spinal cord injury in rat.

Inosine, a purine nucleoside, is one of the novel substances, which can preserve the neuronal and glial viability and stimulate intact neurons to extend axons. We, herein, evaluated the effect of oral inosine treatment on spinal cord injury (SCI) recovery by means of locomotor and bladder function, quantification of neurons and spinal cord tissue sparing. Rats after compression SCI were divided into groups-SCI-Aqua and SCI-Inosine (daily application of aqua for injection or inosine)-locomotion of hind limbs (BBB score) and urinary bladder function were evaluated from day 1 to 28 after SCI. The neuronal profile was determined by immunohistochemistry with NeuN antibodies and tissue sparing by Luxol fast blue staining method. SCI affected the functional movement of hind limbs in both groups with gradual improvement (increased BBB score) during survival. However, we found a significant difference in BBB score and recovery of bladder function between SCI-Aqua and SCI-Inosine groups during the second week of survival following SCI. In addition, the number of NeuN positive cells and percentage of tissue sparing was also significantly higher in SCI-Inosine group when compared with the SCI-Aqua group. Daily oral administration of inosine after SCI throughout the survival was beneficial for locomotion and micturition, neuronal survival and tissue sparing. This indicates that inosine may represent one of the co-stimulatory factors for treatment strategies to promote neuronal plasticity after SCI.

[Effect of preparation "Korargin" on metabolic syndrome manifestations in adult and old rats exposed to x-ray irradiation].

Introduction to the diet of adult and old rats for 30 days after R-irradiation at a dose of 5 Gy drug "Korargin" prevented the development of some manifestations of radioinduced metabolic syndrome (MS) in animals of both age groups: in adult irradiated animals--a tendency to decrease insulin levels in blood plasma, increase of cholesterol levels in liver tissue, significantly increased serum high density lipoprotein as compared both to controls and irradiated animals, prevented the decrease in the levels of anions NO2- and NO3- in tissue of the aorta and anions NO2- in tissue of the heart; in old irradiated animals--prevented tended to increase of body weight, the increase in insulinresistance (index HOMA), the decrease in the level of anions NO2- in the aorta tissue, increased levels of anions NO2- and NO3- in the heart tissue compared to controls. Prevention through drug "Korargin" some manifestations of radioinduced MS in adult and old animals, indicates the prospects of exploring the possibility of correction of the violations of carbohydrate and lipid metabolism caused by exposure to ionizing radiation, in individuals of both age groups.

Inosine alters gene expression and axonal projections in neurons contralateral to a cortical infarct and improves skilled use of the impaired limb.

Recovery after stroke and other types of brain injury is restricted in part by the limited ability of undamaged neurons to form compensatory connections. Inosine, a naturally occurring purine nucleoside, stimulates neurons to extend axons in culture and, in vivo, enhances the ability of undamaged neurons to form axon collaterals after brain damage. The molecular changes induced by inosine are unknown, as is the ability of inosine to restore complex functions associated with a specific cortical area. Using a unilateral injury model limited to the sensorimotor cortex, we show that inosine triples the number of corticospinal tract axons that project from the unaffected hemisphere and form synaptic bouton-like structures in the denervated half of the spinal cord. These changes correlate with improved recovery in animals' ability to grasp and consume food pellets with the affected forepaw. Studies using laser-capture microdissection and microarray analysis show that inosine profoundly affects gene expression in corticospinal neurons contralateral to the injury. Inosine attenuates transcriptional changes caused by the stroke, while upregulating the expression of genes associated with axon growth and the complement cascade. Thus, inosine alters gene expression in neurons contralateral to a stroke, enhances the ability of these neurons to form connections on the denervated side of the spinal cord, and improves performance with the impaired limb.

Inosine prevents hyperlocomotion in a ketamine-induced model of mania in rats.

Bipolar Disorder is a disorder characterized by alternating episodes of depression, mania or hypomania, or even mixed episodes. The treatment consists on the use of mood stabilizers, which imply serious adverse effects. Therefore, it is necessary to identify new therapeutic targets to prevent or avoid new episodes. Evidence shows that individuals in manic episodes present a purinergic system dysfunction. In this scenario, inosine is a purine nucleoside known to act as an agonist of A1 and A2A adenosine receptors. Thus, we aimed to elucidate the preventive effect of inosine on locomotor activity, changes in purine levels, and adenosine receptors density in a ketamine-induced model of mania in rats. Inosine pretreatment (25 mg/kg, oral route) prevented the hyperlocomotion induced by ketamine (25 mg/kg, intraperitoneal route) in the open-field test; however, there was no difference in hippocampal density of A1 and A2A receptors, where ketamine, as well as inosine, were not able to promote changes in immunocontent of the adenosine receptors. Likewise, no effects of inosine pretreatments or ketamine treatment were observed for purine and metabolic residue levels evaluated. In this sense, we suggest further investigation of signaling pathways involving purinergic receptors, using pharmacological strategies to better elucidate the action mechanisms of inosine on bipolar disorder. Despite the limitations, inosine administration could be a promising candidate for bipolar disorder treatment, especially by attenuating maniac phase symptoms, once it was able to prevent the hyperlocomotion induced by ketamine in rats.

Improved Parkinsons disease motor score in a single-arm open-label trial of febuxostat and inosine.

BACKGROUND: Cellular energetics play an important role in Parkinsons disease etiology, but no treatments directly address this deficiency. Our past research showed that treatment with febuxostat and inosine increased blood hypoxanthine and ATP in healthy adults, and a preliminary trial in 3 Parkinson's disease patients suggested some symptomatic improvements with no adverse effects. METHODS: To examine the efficacy on symptoms and safety in a larger group of Parkinsons disease patients, we conducted a single-arm, open-label trial at 5 Japanese neurology clinics and enrolled thirty patients (nmales = 11; nfemales = 19); 26 patients completed the study (nmales = 10; nfemales = 16). Each patient was administered febuxostat 20 mg and inosine 500 mg twice-per-day (after breakfast and dinner) for 8 weeks. The primary endpoint was the difference of MDS-UPDRS Part III score immediately before and after 57 days of treatment. RESULTS: Serum hypoxanthine concentrations were raised significantly after treatment (Pre = 11.4 µM; Post = 38.1 µM; P < .0001). MDS-UPDRS Part III score was significantly lower after treatment (Pre = 28.1 ±â€Š9.3; Post = 24.7 ±â€Š10.8; mean ±â€ŠSD; P = .0146). Sixteen adverse events occurred in 13/29 (44.8%) patients, including 1 serious adverse event (fracture of the second lumbar vertebra) that was considered not related to the treatment. CONCLUSIONS: The results of this study suggest that co-administration of febuxostat and inosine is relatively safe and effective for improving symptoms of Parkinsons disease patients. Further controlled trials need to be performed to confirm the symptomatic improvement and to examine the disease-modifying effect in long-term trials.

Inosine protects against impairment of memory induced by experimental model of Alzheimer disease: a nucleoside with multitarget brain actions.

RATIONALE: Inosine is a naturally occurring purine nucleoside formed by adenosine breakdown. This nucleoside is reported to exert potent effects on memory and learning, possibly through its antioxidant and anti-inflammatory actions. OBJECTIVE: The objective is to evaluate the effects of inosine on the behavioral and neurochemical parameters in a rat model of Alzheimer's disease (AD) induced by streptozotocin (STZ). METHODS: Adult male rats were divided into four groups: control (saline), STZ, STZ plus inosine (50 mg/kg), and STZ plus inosine (100 mg/kg). STZ (3 mg/kg) was administered by bilateral intracerebroventricular injection. The animals were treated intraperitoneally with inosine for 25 days. Memory, oxidative stress, ion pump activities, acetylcholinesterase (AChE), and choline acetyltransferase (ChAT) activities and expression were evaluated in the cerebral cortex and hippocampus. RESULTS: The memory impairment induced by STZ was prevented by inosine. An increase in the Na+, K+-ATPase, and Mg-ATPase activities and a decrease in the Ca2+-ATPase activity were induced by STZ in the hippocampus and cerebral cortex, and inosine could prevent these alterations in ion pump activities. Inosine also prevented the increase in AChE activity and the alterations in AChE and ChAT expression induced by STZ. STZ increased the reactive oxygen species, nitrite levels, and superoxide dismutase activity and decreased the catalase and glutathione peroxidase activities. Inosine treatment conferred protection from these oxidative alterations in the brain. CONCLUSIONS: Our findings demonstrate that inosine affects brain multiple targets suggesting that this molecule may have therapeutic potential against cognitive deficit and tissue damage in AD.

Role of uric acid in multiple sclerosis.

In the past decade, a growing number of evidence has implicated free radicals in a variety of pathophysiological conditions including aging, cancer, and coronary heart disease. Analyses of different aspects of multiple sclerosis (MS) pathology with respect to oxidative damage have also revealed evidence of free radical injury to the central nervous system (CNS), although attempts to protect the CNS using various antioxidants have met with only moderate success. Several recent studies have reported lower levels of uric acid (UA), a major scavenger of reactive nitrogen species, in MS patients, while other studies found no such correlation. Here, we discuss these studies as well as current efforts to manipulate serum UA levels in MS patients.

Comparison of elimination and cardiovascular effects of adenine nucleosides administered intrapericardially or intravenously in anesthetized dog.

Intrapericardial (IP) administration of certain cardioactive agents allows investigation of local pharmacological actions on the heart and may carry potential benefit to influence myocardial function. The cardioprotective adenosine (ADO) and inosine (INO) may be the most representative candidates. Elimination and cardiovascular effects of IP and intravenously (IV) applied ADO and INO were compared on anesthetized dogs. Their pericardial and systemic concentrations were measured after consecutive administration of increasing ADO and INO doses. In the case of IP administration at the end of the incubation period, pericardial concentrations of adenine nucleosides significantly exceeded the control values. However, the IV applied ADO and INO were rapidly metabolized in the systemic plasma. As characteristic hemodynamic effects, small but sustained decrease in heart rate (IP ADO) and increase in myocardial contractility (IP INO) were observed. During IV administration, ADO and INO exerted remarkable effects on all hemodynamic variables, which then gradually disappeared in 15 minutes. In summary, the elimination of ADO and INO was significantly slower in the pericardial fluid than in the plasma. Considering the balanced cardiac actions and lack of strong systemic hemodynamic effects, IP administration of adenine nucleosides may suggest a promising approach in the local treatment of the diseased heart.

In vitro pharmacology of inosine, with special reference to possible interactions with capsaicin-sensitive mechanisms and inflammatory mediators.

The in vitro pharmacology of inosine (Ino), a putative anti-inflammatory compound, has been investigated in smooth muscle preparations, with emphasis on its possible interaction with known inflammatory mediators, as well as capsaicin, an inducer of "neurogenic inflammation". The highest concentration of Ino routinely studied was 1 mM, since 10 mM nonspecifically inhibited many types of smooth muscle motor responses. In the guinea pig isolated ileum or trachea, Ino (1 mM) failed to influence the excitatory effect of capsaicin. The nitric oxide (NO)-mediated relaxant effect of capsaicin in the human colonic circular muscle was not influenced by Ino. Ino only weakly reduced the contractile effect of histamine on the guinea pig ileum. Substance P-mediated nonadrenergic, noncholinergic (NANC) contractions evoked by electrical stimulation in the guinea pig ileum were inhibited by half by Ino (1 mM). Ino showed no or only a weak inhibitory effect on NANC relaxation of the rat ileum. Arachidonic acid- or leukotriene D(4)-induced contractions of the guinea pig ileum were only moderately inhibited by Ino. Collectively, these results indicate that Ino (up to 1 mM) shows no major antagonist activity at histamine H(1) receptors, leukotriene CysLT(1) receptors, the transient receptor potential channel TRPV1 or tachykinin NK(1) or NK(2) receptors, or cyclooxygenase-inhibitory activity. Therefore, its anti-inflammatory activity is probably not associated with these mechanisms. The in vitro methods used in this study are capable of detecting a wide range of biological effects and hence may be recommended as a screening procedure for potential drugs or natural products.

Transition to 37°C reveals importance of NADPH in mitigating oxidative stress in stored RBCs.

The RBC storage lesion is a multiparametric response that occurs during storage at 4°C, but its impact on transfused patients remains unclear. In studies of the RBC storage lesion, the temperature transition from cold storage to normal body temperature that occurs during transfusion has received limited attention. We hypothesized that multiple deleterious events might occur in this period of increasing temperature. We show dramatic alterations in several properties of therapeutic blood units stored at 4°C after warming them to normal body temperature (37°C), as well as febrile temperature (40°C). In particular, the intracellular content and redox state of NADP(H) were directly affected by post-storage incubation at 37°C, as well as by pro-oxidant storage conditions. Modulation of the NADPH-producing pentose phosphate pathway, but not the prevention of hemoglobin autoxidation by conversion of oxyhemoglobin to carboxyhemoglobin, provided protection against storage-induced alterations in RBCs, demonstrating the central role of NADPH in mitigating increased susceptibility of stored RBCs to oxidative stress. We propose that assessing RBC oxidative status after restoration of body temperature constitutes a sensitive method for detecting storage-related alterations that has the potential to improve the quality of stored RBCs for transfusion.

Inosine Accelerates the Regeneration and Anticipates the Functional Recovery after Sciatic Nerve Crush Injury in Mice.

Trauma to the peripheral nervous system (PNS) results in loss of motor and sensory functions. After an injury, a complex series of events begins, allowing axonal regeneration and target reinnervation. However, this regenerative potential is limited by several factors such as age, distance from the lesion site to the target and severity of lesion. Many studies look for ways to overcome these limitations. Inosine, a purine nucleoside derived from adenosine, emerges as a potential treatment, due to its capacity to regulate axonal growth, neuroprotection and immunomodulation, contributing to motor recovery. However, no studies demonstrated their effects on PNS. C57/Black6 mice were submitted to sciatic nerve crush and received intraperitoneal injections of saline or inosine (70 mg/kg), one hour after injury and daily for one week. To evaluate axonal regeneration and functional recovery, electroneuromyography, Sciatic Function Index (SFI), rotarod and pinprick tests were performed. Our results showed that the inosine group presented a higher number of myelinated fibers and a large amount of fibers within the ideal G-ratio. In addition, the results of electroneuromyography showed greater amplitude of the compound muscle action potentials in the first and second weeks, suggesting anticipation of regeneration in the inosine group. We also observed in the inosine group, motor and sensory neurons survival, reduction in the number of macrophages and myelin ovoids in the sciatic nerves, and an early recovery of motor and sensory functions. Thus, we conclude that the use of inosine accelerates axonal regeneration promoting an early recovery of motor and sensory functions.

Inosine promotes recovery of skilled motor function in a model of focal brain injury.

Recovery of function following traumatic brain injury (TBI) is partly through neuronal plasticity. However plasticity is limited in the adult CNS compared with young animals. In order to test whether treatments that enhance CNS plasticity might improve functional recovery after TBI, a new rat head injury model was developed, in which a computer-controlled impactor produced full thickness lesions of the forelimb region of the sensorimotor cortex. Behavioural deficits were seen in several sensorimotor tasks, most of which recovered spontaneously by 21 days. However, skilled paw reaching behaviour, a task that requires corticospinal function, was only approximately 40% recovered by 28 days. In order to promote plasticity inosine was infused into the lateral ventricles for 28 days. This treatment produced an almost complete recovery of skilled paw reaching ability, associated with sprouting of the uninjured corticospinal axons across the midline into the territory of the lesioned pathway. In the cervical spinal cord the number of corticospinal axons originating from the uninjured cortex that innervated the contralateral cervical cord was five times that of controls, and in the red nucleus the number of contralaterally projecting axons was four times control values. Inosine treatment did not affect recovery in unskilled behavioural tasks, most of which recovered to normal levels by 28 days without treatment. Animals were placed in an enriched environment as an alternative method to promote plasticity. This resulted in more rapid recovery in several tasks including skilled paw function, but by 28 days normally housed animals had caught up to the same level of improvement.

Inosine ameliorates the effects of hemin-induced oxidative stress in broilers.

The objective of these studies was to determine whether inosine, a precursor of the antioxidant uric acid, can ameliorate hemin-induced oxidative stress. Dietary inclusion of inosine was begun either before or after hemin-induced oxidative stress. Broilers (4 weeks) were divided into four treatment groups (Control, Hemin, Inosine, Hemin/Inosine). Throughout the study control birds (n=10) were injected daily with a buffer solution, while hemin birds (n=10) were injected daily (i.p.) with a 20 mg/kg body weight hemin buffer solution. Leukocyte oxidative activity (LOA) and concentrations of plasma uric acid (PUA) were measured. Results from the first study showed that hemin birds had increased levels of LOA (P=0.0333) and lower PUA (P=0.1174). On day 10, control and hemin birds were subdivided into inosine birds (n=5) and hemin/inosine birds (n=5). These birds were given 0.6 M/kg of feed/day of dry inosine. Plasma concentrations of uric acid and LOA were then measured on day 15. Results showed that inosine raised concentrations of PUA (P=0.0001) and lowered LOA (P=0.0044) as induced by hemin. In the second study pretreatment of broilers with hemin prevented the increase in LOA induced by hemin (P=0.0001). These results show that modulating the concentrations of uric acid can markedly affect oxidative stress.

Pharmacokinetic properties of a novel inosine analog, 4'-cyano-2'-deoxyinosine, after oral administration in rats.

4'-cyano-2'-deoxyinosine (SK14-061a), a novel nucleoside analog based on inosine, has antiviral activity against the human immunodeficiency virus type 1 that has the ability to acquire resistance against many types of reverse transcriptase inhibitors based on nucleosides. The aim of this study was to investigate the pharmacokinetics studies after its oral administration to rats. For this purpose, we first developed and validated an analytical method for quantitatively determining SK14-061a levels in biological samples by a UPLC system interfaced with a TOF-MS system. A rapid, simple and selective method for the quantification of SK14-061a in biological samples was established using liquid chromatography mass spectrometry (LC-MS) with solid phase extraction. The pharmacokinetic properties of SK14-061a in rats after oral administration were then evaluated using this LC-MS method. SK14-061a was found to be relatively highly bioavailable, is rapidly absorbed from the intestinal tract, and is then mainly distributed to the liver and then ultimately excreted via the urine in an unchanged form. Furthermore, the simultaneous administration of SK14-061a with the nucleoside analog, entecavir, led to a significant alteration in the pharmacokinetics of SK14-061a. These results suggest that the SK14-061a has favorable pharmacokinetic properties with a high bioavailability with the potential for use in oral pharmaceutical formulations, but drug-drug interactions should also be considered.