Automated experimental system capturing three behavioral components during murine forced swim test

AimsAn automated experimental system applying a commercially available video image analyzer was developed for the simultaneous detection and measurement of three behavioral components; immobility, swimming (horizontal movements) and climbing (vertical movements) that occur in the murine forced swim test (FST). The system was validated using four typical antidepressants.Main methodsSystem validity was confirmed by demonstrating no significant difference in 6 min time course of control group and imipramine-dosed group (30 mg/kg) between manual examinations and automated digital analysis for all the three behaviors (i.e., correlation coefficients were 0.96, 0.83 and 0.94 for immobility, swimming and climbing, respectively). The effects of acute single treatment with four antidepressants in clinical use, i.e., imipramine, desipramine, bupropion and fluvoxamine were evaluated at doses of 15, 30 and 60 mg/kg using the system.Key findingsIn 2–4 min time span analysis, all four antidepressants reduced immobility and increased climbing significantly, desipramine and bupropion increased swimming significantly, while imipramine and fluvoxamine did not.SignificanceThe automated experimental system enabled efficient and accurate analysis of the three murine behaviors during FST at once. Climbing could be more sensitive parameter to detect anti-depressant-like effect than immobility in this system.     

Different roles of zinc plus arachidonic acid on insulin sensitivity between high fructose- and high fat-fed rats

AimsThis study was to determine the effects of zinc plus arachidonic acid (ZA) treatment on the insulin action in the specific ZA target organs using hyperinsulinemic euglycemic clamp method.Main methods18 Sprague–Dawley rats weighing ~ 130 g were divided into 3 groups of 6 rats and treated them with 1) normal rat chow, 2) high fructose (60.0%) diet only, or 3) the same fructose diet plus drinking water containing 10 mg zinc plus 50 mg arachidonic acid (AA)/L. In a separate study, male Wistar rats weighing ~ 250 g were fed normal rat chow (n = 4) or high fat (66.5%) diet with drinking water containing zero (n = 9) or 10 mg AA plus 20 mg zinc /L (n = 9). After 4 week treatment, insulin action was assessed using the hyperinsulinemic eguglycemic clamp technique.Key findingsHigh fructose feeding impaired suppression of hepatic glucose output by insulin compared to controls during the clamp procedure (4.39 vs. 2.35 mg/kg/min; p < 0.05). However, ZA treatment in high fructose-fed rats showed a significant improvement of hepatic insulin sensitivity compared to non-treatment controls (4.39 vs. 2.18 mg/kg/min; p < 0.05). Glucose infusion rates in Wistar rats maintained on a high fat diet (HFD) were significantly lower compared to control rats (22.8 ± 1.3 vs. 31.9 ± 1.4 mg/kg/min; p < 0.05). ZA treatment significantly improved (~ 43%) peripheral tissue insulin sensitivity in HFD fed animals (26.7 ± 1.3 [n = 9] vs. 22.8 ± 1.3 mg/kg/min; p < 0.05).SignificanceThese data demonstrate that ZA treatment is effective in improving glucose utilization in hyperglycemic rats receiving either a high-fructose or a high-fat diet.     

Involvement of src-kinase activation in ischemic preconditioning induced protection of mouse brain

AimsTo investigate the role of src-kinase in ischemic preconditioning induced reversal of ischemia and reperfusion induced cerebral injury in mice.Main methodsBilateral carotid artery occlusion of 17 min followed by reperfusion for 24 h was employed to produce ischemia and reperfusion induced cerebral injury in mice. Cerebral infarct size was measured using triphenyltetrazolium chloride staining using both by volume and by weight methods differently. Memory was evaluated using elevated plus maze test. Rota rod test was employed to assess motor incoordination.Key findingsBilateral carotid artery occlusion followed by reperfusion produced cerebral infarction and impaired memory and motor co-ordination. Three preceding episodes of bilateral carotid artery occlusion for 1 min and reperfusion of 1 min (ischemic preconditioning) prevented markedly ischemia–reperfusion-induced cerebral injury measured in terms of infarct size (38.5 ± 1.3% and 38.5 ± 2.9% mean infarct of control animals was reduced to 24.3 ± 1.2% and 23.5 ± 1.8% of the preconditioning groups respectively), loss of memory (72.2 ± 3.6 mean transfer latency time of control animals was reduced to 25.6 ± 5.2 of the preconditioning group respectively) and motor coordination (78.3 ± 17.6 s mean falling down latency time of control animals was increased to a mean value of 180.9 ± 6.5 s of the preconditioning groups respectively). SU6656 (2 mg/kg, ip) and PP1 (0.1 mg/kg, ip), highly selective src-kinase inhibitors, attenuated this neuroprotective effect of ischemic preconditioning.SignificanceTherefore, neuroprotective effect of ischemic preconditioning may be due to src-kinase linked mechanism.     

Effect of different propranolol doses on skeletal structural and mechanic efficiency in an animal model of growth retardation

ObjectiveTo assess in a growth retardation (GR) model the impact of different propranolol (P) doses on anthropomorphometric and biomechanical variables of the appendicular skeleton.Materials and methodsTwenty-one day-old male Wistar rats were divided into the following groups: control (C), C + P3.5 (CP3.5); C + P7 (CP7); C + P10.5 (CP10.5); C + P14 (CP14); ED, ED + P3.5 (EDP3.5); ED + P7 (EDP7); ED + P10.5 (EDP10.5), and ED + P14 (EDP14). Control animals with/without P were fed a rodent diet ad libitum. GR rats with/without P were given 80% of the same diet per 100 g body weight for 4 weeks (T4). Propranolol 3.5, 7, 10.5, and 14 mg/kg/day was intraperitoneally injected 5 days/week for 4 weeks to the CP3.5 and EDP3.5; CP7 and EDP7; CP10.5 and EDP10.5, and CP14 and EDP14 groups respectively.ResultsAt T4, energy restriction had negative effects upon overall growth, femur, and its mechanical competence. Propranolol improved bone rigidity in GR animals at doses of 7 and 10.5 mg/kg/day, with a maximum response at 7 mg/kg/day.ConclusionsPropranolol 7 mg/kg/day would be the most effective dose for modeling incorporation of bone, as shown by the increased skeletal structural and mechanic efficiency in this animal model of growth retardation. Such effect may result from maintenance of mechanosensor viability, changes in its sensitivity, the biomechanical reference point and/or effector response in GR rats.     

Antidepressant-like profile and MAO-A inhibitory activity of 4-propyl-2H-benzo[h]-chromen-2-one

AimsTo evaluate the central nervous pharmacological profile of 4-propyl-2H-benzo[h]-chromen-2-one (FCS-304) in ICR mice and its monoamine oxidase inhibitor activity.Main methodsFCS-304 was evaluated in screening test of central nervous system in ICR mice and against MAO activity.Key findingsFCS-304 (25–200 mg/Kg, p.o.) significantly reduced immobility time during the forced swimming test (FST) and tail suspension test (TST), but did not show effects in the rota-rod tests, maximal electroshock seizures (MES), pentylenetetrazole seizures, light–dark box, barbiturate sleeping time and cold plate tests. Furthermore, FCS-304 inhibited monoamine oxidase A (MAO-A) with IC₅₀: 2.28 ± 0.15 µM, but not MAO-B.SignificanceThese results suggest that FCS-304 could elicit antidepressant effects related to MAO-A inhibitory activity.     

Rb1 postconditioning attenuates liver warm ischemia-reperfusion injury through ROS-NO-HIF pathway

AimsGinsenoside Rb1 could prevent ischemic neuronal death and focal cerebral ischemia, but its roles to liver warm I/R injury remain to be defined. We determined if Rb1 would attenuate warm I/R injury in mice.Main methodsMice were divided into sham, I/R, Rb1 + I/R (Rb1 postconditioning, 20 mg/kg, i.p. after ischemia), sham + L-NAME, I/R + L-NAME, and Rb1 + I/R + L-NAME groups using 60 min of the liver median and left lateral lobes ischemia. Serum levels of alanine aminotransferase (ALT) were measured and morphology changes of livers were evaluated. Contents of nitric oxide (NO) and nitric oxide synthase (NOS), malondialdehye (MDA) and activity of superoxide dismutase (SOD) were measured. Expressions of Akt, p-Akt, iNOS, HIF-1alpha, tumor necrosis factor-a (TNF-α) and intercellular adhesion molecule-1 (ICAM-1) were also determined by western blot or immunohistochemistry.Key findingsRb1 postconditioning attenuated the dramatically functional and morphological injuries. The levels of ALT were significantly reduced in Rb1 group (p < 0.05). Rb1 upregulated the concentrations of NO, iNOS in serum, iNOS, and activity of SOD in hepatic tissues (p < 0.05), while it dramatically reduced the concentration of MDA (p < 0.05). Protein expressions of p-Akt, iNOS and HIF-1alpha were markedly enhanced in Rb1 group. Protein and mRNA expressions of TNF-α and ICAM-1 were markedly suppressed by Rb1 (p < 0.05).SignificanceWe found that Rb1 postconditioning could protect liver from I/R injury by upregulating the content of NO and NOS, and also HIF-1alpha protein expression. These protective effects could be abolished by L-NAME. These findings suggested Rb1 may have the therapeutic potential through ROS-NO-HIF pathway for management of liver warm I/R injury.     

Suppressing inflammatory cascade by cyclo-oxygenase inhibitors attenuates quinolinic acid induced Huntington's disease-like alterations in rats

AimsThe aim of this study was to investigate the protective effects of cyclo-oxygenase inhibitors against quinolinic acid (QA) induced Huntington's disease-like alterations in rats.Main methodsQuinolinic acid (300 nmol) was administered intrastriatally into the striatum to induce Huntington's disease-like alteration. Cyclo-oxygenase inhibitors celecoxib (15 and 30 mg/kg) and meloxicam (10 and 20 mg/kg) were given for 21 days. In behavioral assessment locomotor, rotarod, and balance beam walk performances were assessed. Oxidative stress, mitochondrial dysfunction, proinflammatory cytokines and caspase-3 were assessed on day 21 after behavioral assessments.Key findingsIntrastriatal quinolinic acid (300 nmol) administration significantly altered the body weight, motor coordination, and induced oxidative damage (as indicated by the increase in lipid peroxidation and nitrite concentration) in the striatum as compared to sham group. Besides quinolinic acid (300 nmol) significantly depleted the mitochondrial enzyme complex levels and increased TNF-α, IL-6 and caspase-3 (marker of apoptotic cell death) levels in the striatum. Chronic treatment with celecoxib (15 and 30 mg/kg) significantly attenuated the quinolinic acid-induced behavioral and biochemical alterations, while meloxicam was able to reverse behavioral alterations at higher dose (20 mg/kg) as compared to the quinolinic acid treated group. Chronic treatment with the selective COX-2 inhibitors significantly restored the mitochondrial enzyme complex activities as well as attenuated TNF-α, IL-6 and caspase-3 levels as compared to the quinolinic acid treated group.SignificanceResults of the present study demonstrate the protective effect of cyclo-oxygenase inhibitors in the experimental models of Huntington's disease; and further provide evidence toward the involvement of neuroinflammatory cascade in the pathogenesis of Huntington's disease.     

Polaprezinc prevents ongoing thioacetamide-induced liver fibrosis in rats

AimsCirrhotic patients commonly have a liver zinc deficiency, which may aggravate liver fibrosis due to the lack of antioxidative effects of zinc. This study examined the ability of polaprezinc, N-(3-aminopropionyl)-l-histidinato zinc, to prevent fibrosis in a rat model of thioacetamide (TAA)-induced hepatic fibrosis.Main methodsLiver cirrhosis was induced by orally administering TAA for 20 weeks. The rats were cotreated with one of the following for the last 10 weeks of TAA treatment: (1) polaprezinc (50 or 200 mg/kg/day); (2) l-carnosine (155 mg/kg/day), which contained equal amounts of l-carnosine as 200 mg/kg/day polaprezinc; (3) zinc sulfate (112 mg/kg/day) or (4) zinc-l-aspartic complex (317.8 mg/kg/day). Both zinc supplementations contained equal amounts of zinc as high-dose polaprezinc.Key findingsHepatic zinc levels fell significantly in rats treated with TAA for 20 weeks. Cotreating with high-dose polaprezinc and zinc-l-aspartic complex for 10 weeks prevented hepatic zinc loss. Hepatic hydroxyproline and tissue inhibitor of metalloproteinases-1 (TIMP-1) were significantly higher in rats treated with TAA for 20 weeks than 10 weeks, whereas polaprezinc prevented changes in these fibrosis markers and reduced hepatic transforming growth factor-β1 protein concentration, macroscopic and histologic changes. TAA caused oxidative stress-related changes in the liver that were prevented by high-dose polaprezinc and partially by zinc-l-aspartic complex. Treatment with l-carnosine, low-dose polaprezinc or zinc sulfate for 10 weeks did not affect liver fibrosis progression or oxidative stress-related changes.SignificancePolaprezinc may prevent ongoing fibrosis by preventing zinc depletion, oxidative stress and fibrosis markers in cirrhotic livers.     

Meal timing and composition influence ghrelin levels, appetite scores and weight loss maintenance in overweight and obese adults

BackgroundAlthough dietary restriction often results in initial weight loss, the majority of obese dieters fail to maintain their reduced weight. Diet-induced weight loss results in compensatory increase of hunger, craving and decreased ghrelin suppression that encourage weight regain. A high protein and carbohydrate breakfast may overcome these compensatory changes and prevent obesity relapse.MethodsIn this study 193 obese (BMI 32.2 ± 1.0 kg/m²), sedentary non diabetic adult men and women (47 ± 7 years) were randomized to a low carbohydrate breakfast (LCb) or an isocaloric diet with high carbohydrate and protein breakfast (HCPb). Anthropometric measures were assessed every 4 weeks. Fasting glucose, insulin, ghrelin, lipids, craving scores and breakfast meal challenge assessing hunger, satiety, insulin and ghrelin responses, were performed at baseline, after a Diet Intervention Period (Week 16) and after a Follow-up Period (Week 32).ResultsAt Week 16, groups exhibited similar weight loss: 15.1 ± 1.9 kg in LCb group vs. 13.5 ± 2.3 kg in HCPb group, p = 0.11. From Week 16 to Week 32, LCb group regained 11.6 ± 2.6 kg, while the HCPb group lost additional 6.9 ± 1.7 kg. Ghrelin levels were reduced after breakfast by 45.2% and 29.5% following the HCPb and LCb, respectively. Satiety was significantly improved and hunger and craving scores significantly reduced in the HCPb group vs. the LCb group.ConclusionA high carbohydrate and protein breakfast may prevent weight regain by reducing diet-induced compensatory changes in hunger, cravings and ghrelin suppression. To achieve long-term weight loss, meal timing and macronutrient composition must counteract these compensatory mechanisms which encourage weight regain after weight loss.     

Hemodynamic effects of inducible nitric oxide synthase inhibition combined with sildenafil during acute pulmonary embolism

While endogenous nitric oxide (NO) may be relevant to the beneficial hemodynamic effects produced by sildenafil during acute pulmonary embolism (APE), huge amounts of inducible NO synthase (iNOS)-derived NO may contribute to lung injury. We hypothesized that iNOS inhibition with S-methylisothiourea could attenuate APE-induced increases in oxidative stress and pulmonary hypertension and, therefore, could improve the beneficial hemodynamic and antioxidant effects produced by sildenafil during APE. Hemodynamic evaluations were performed in non-embolized dogs treated with saline (n = 4), S-methylisothiourea (0.01 mg/kg followed by 0.5 mg/kg/h, n = 4), sildenafil (0.3 mg/kg, n = 4), or S-methylisothiourea followed by sildenafil (n = 4), and in dogs that received the same drugs and were embolized with silicon microspheres (n = 8 for each group). Plasma nitrite/nitrate (NOx) and thiobarbituric acid reactive substances (TBARS) concentrations were determined by Griess and a fluorometric assay, respectively. APE increased mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance index (PVRI) by 25 ± 1.7 mm Hg and by 941 ± 34 dyn s cm^?5 m^?2, respectively. S-methylisothiourea neither attenuated APE-induced pulmonary hypertension, nor enhanced the beneficial hemodynamic effects produced by sildenafil after APE (>50% reduction in pulmonary vascular resistance). While sildenafil produced no change in plasma NOx concentrations, S-methylisothiourea alone or combined with sildenafil blunted APE-induced increases in NOx concentrations. Both drugs, either alone or combined, produced antioxidant effects. In conclusion, although iNOS-derived NO may play a key role in APE-induced oxidative stress, our results suggest that the iNOS inhibitor S-methylisothiourea neither attenuates APE-induced pulmonary hypertension, nor enhances the beneficial hemodynamic effects produced by sildenafil.     

Effects of oral administration of (L)-arginine, (L)-NAME and allopurinol on intestinal ischemia/reperfusion injury in rats

AimsIntestinal ischemia/reperfusion (I/R) injury is implicated in many clinical conditions, and it performs a fundamental role in their pathophysiologies. Oral administration of antioxidants and nitric oxide (NO) donors ameliorate intestinal injury. Here, the effects of l-arginine, allopurinol and N^G-nitro-l-arginine methyl ester (l-NAME) were investigated.Main methodsOne hundred twenty-eight male Wistar rats were separated into 4 groups and subjected to occlusion of the superior mesenteric artery for 60 min. The Control group did not receive any substance before the surgical operation. However, the 3 other groups received the following: l-arginine (800 mg/kg body weight; l-Arg group), l-NAME (50 mg/kg; l-NAME group) or allopurinol (100 mg/kg; Allo group). Each substance was given by mouth in 3 equal doses 24, 12 and 1 h before the surgical operation. Each group was then divided into 4 subgroups, which underwent different durations of reperfusion (0, 1, 8 or 24 h). At the end of each time point, blood and tissue samples were collected, and histological examinations were performed. Serum nitrite and catalase, intestinal tissue myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) levels were determined.Key findingsAt each reperfusion time point, the Allo group exhibited the mildest histological lesions in contrast to the l-NAME group, which showed the most severe lesions. MPO was decreased significantly in the Allo and l-Arg groups during reperfusion, and allopurinol administration caused earlier and stronger effect. iNOS and NT levels were higher in the l-Arg group and lower in the Allo group. Serum nitrite and catalase were increased in the l-NAME group after 24 h.SignificanceOral administration of allopurinol exerted a strong and protective effect on the intestinal tissue that was subjected to I/R earlier than l-arginine. This finding was also supported with the MPO, iNOS and NT data.     

The effect of tumor necrosis factor-α inhibitor soon after hypoxia-ischemia on heart in neonatal rats

AimsPerinatal hypoxic-ischemic insult has acute and long term deleterious effects on many organs including heart. Although tumor necrosis factor alpha (TNF-α) has been reported to increase soon after hypoxia, the inhibition of this mediator has not been documented. The aim of this study was to investigate the effects of a TNF-α inhibitor (etanercept) on contractility and ultrastructure of rat heart muscles exposed to hypoxia-ischemia during neonatal period.Main methodsForty-five seven-day old rats divided into three groups were included in this study. The right carotid arteries of Saline and Etanercept groups of rats were ligated and kept in a hypoxia chamber containing 8% oxygen for 2 h. Immediately after hypoxia, while Etanercept group was administered 10 mg/kg etanercept, Saline group had only saline intraperitoneally. The carotid arteries of rats in Sham group were located without ligation and hypoxia. Mechanical activity of heart was recorded and tissue samples were examined by electron microscopy in the sixteenth week following the hypoxia-ischemia.Key findingsWhile atrial contractile force in Etanercept group was similar to Sham group, there was significant decrease in Saline group (p < 0.001). However, there was only non-significant decrease in ventricular contractility of Saline group comparing to Sham group (p > 0.05). After hypoxia-ischemia, ultrastructural degenerative changes and mitochondrial damage in atriums of Etanercept group were significantly less severe than Saline group.SignificanceThis study demonstrated that neonatal hypoxia-ischemia caused long term cardiac dysfunction and ultrastructural degenerative changes in the heart of rats. TNF-α inhibitor administration soon after hypoxia-ischemia may have heart protective effect.     

NADPH-d and Fos reactivity in the rat spinal cord following experimental spinal cord injury and embryonic neural stem cell transplantation

AimsThe aim of this study is to determine the role of nitric oxide (NO) in neuropathic pain and the effect of embryonic neural stem cell (ENSC) transplantation on NO content in rat spinal cord neurons following spinal cord injury (SCI).Main methodsNinety adult male Sprague–Dawley rats were divided into 3 groups (n = 30, each): control (laminectomy), SCI (hemisection at T12–T13 segments) and SCI + ENSC. Each group was further divided into sub-groups (n = 5 each) based on the treatment substance (L-NAME, 75 mg/kg/i.p.; l-arginine, 225 mg/kg/i.p.; physiological saline, SF) and duration (2 h for acute and 28 days for chronic groups). Pain was assessed by tail flick and Randall–Selitto tests. Fos immunohistochemistry and NADPH-d histochemistry were performed in segments 2 cm rostral and caudal to SCI.Key findingsTail-flick latency time increased in both acute and chronic L-NAME groups and increased in acute and decreased in chronic l-arginine groups. The number of Fos (+) neurons decreased in acute and chronic L-NAME and decreased in acute l-arginine groups. Following ENSC, Fos (+) neurons did not change in acute L-NAME but decreased in the chronic L-NAME groups, and decreased in both acute and chronic l-arginine groups. NADPH-d (+) neurons decreased in acute L-NAME and increased in l-arginine groups with and without ENSC transplantation.SignificanceThis study confirms the role of NO in neuropathic pain and shows an improvement following ENSC transplantation in the acute phase, observed as a decrease in Fos(+) and NADPH-d (+) neurons in spinal cord segments rostral and caudal to injury.     

Baicalin upregulates the genetic expression of antioxidant enzymes in Type-2 diabetic Goto-Kakizaki rats

AimThe primary purpose of this study was to characterize and investigate the antioxidant and anti-diabetic activities of the flavonoid baicalin in type 2 diabetic Goto-Kakizaki rats.Main methodsFour groups of Goto-Kakizaki rats (n = 6) were subjected to the following oral treatments for 30 days: (1) metformin — 500 mg/kg (2) baicalin — 120 mg/kg (3) metformin 500 mg/kg and baicalin — 120 mg/kg (4) vehicle treated diabetic controls receiving distilled water. The plasma glucose, triglyceride, total cholesterol, lipid peroxide and protein carbonyl contents were measured on a weekly basis. Following the completion of the treatment, the rats were sacrificed and their blood, heart, pancreatic and hepatic tissues were collected for analysis. The antioxidant enzyme activities as well as their expression were quantified using Western Blot, microarray and RT-PCR.Key findingsThe respective analyses showed that the baicalin- and the metformin and baicalin-treated groups had statistically significant increases (p < 0.05) in the activity and expression of the antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) compared with vehicle- and metformin-treated groups. Further complementing the antioxidant enzyme activity increases, the oxidative stress markers of plasma lipid peroxide and protein carbonyl contents were reduced in these groups as well. These treatment groups also had reduced plasma total cholesterol and triglyceride levels compared with vehicle-treated and metformin-treated groups (p < 0.05).SignificanceBaicalin was an efficient antioxidant in reducing hyperglycemia-induced oxidative stress through the increased expression of antioxidant enzyme activities. It was also an efficient anti-hypertriglyceridemic as well as anti-hypercholesterolemic agent compared with metformin.     

Low serum zinc levels in patients undergoing coronary angiography correlate with immune activation and inflammation

IntroductionLow serum zinc concentrations are associated with adverse outcomes. To explain this phenomenon we aimed to investigate whether low zinc levels are related to immune activation, renal function and coronary artery disease (CAD).MethodsSerum concentrations of zinc and the immune activation markers neopterin and C-reactive protein (CRP) were measured in 2048 patients derived from the LUdwigshafen RIsk and Cardiovascular Health (LURIC) study, a cohort study among patients referred for coronary angiography.ResultsZinc concentrations did not differ between patients with CAD (mean ± SD: 13.3 ± 2.4 μmol/L) and controls (13.3 ± 2.2 μmol/L; Welch's t test: p = n.s.) but CAD patients had higher neopterin (8.6 ± 7.4 nmol/L) and CRP (9.7 ± 19.6 mg/L) concentrations compared to controls (neopterin: 7.5 ± 4.8 nmol/L, p = 0.0005; CRP: 5.5 ± 10.0 mg/L, p < 0.0001). There was an inverse correlation between serum zinc concentrations and neopterin (Spearman's rank correlation: r_s = ?0.222) and CRP (r_s = ?0.166; both p < 0.0001) concentrations.ConclusionsOur results indicate increased inflammatory processes in patients with low zinc levels. Further studies should clarify whether inflammation related processes such as renal wasting contribute to zinc deficiency and underlie the adverse health consequences of low serum zinc levels.     

Involvement of potassium channels in the antidepressant-like effect of venlafaxine in mice

AimsStudies have shown that the acute administration of venlafaxine elicits an antidepressant-like effect in the mouse forced swim test (FST) by a mechanism dependent on the l-arginine–nitric oxide (NO)–cyclic guanosine monophosphate (cGMP) pathway. Because it has been reported that NO activates different types of potassium (K⁺) channels in the brain, this study investigated the involvement of K⁺ channels in the antidepressant-like effect of venlafaxine in the mouse FST.Main methodsMale adult Swiss mice were pretreated with different K⁺ channel inhibitors or openers 15 min before venlafaxine administration. After 30 min, the open-field test (OFT) and FST were carried out.Key findingsIntracerebroventricular (i.c.v.) pretreatment of mice with subeffective doses of tetraethylammonium (TEA, a non-specific inhibitor of K⁺ channels, 25 pg/site), glibenclamide (an ATP-sensitive K⁺ channel inhibitor, 0.5 pg/site), charybdotoxin (a large- and intermediate-conductance calcium-activated K⁺ channel inhibitor, 25 pg/site) or apamin (a small-conductance calcium-activated K⁺ channel inhibitor, 10 pg/site) was able to potentiate the action of a subeffective dose of venlafaxine (2 mg/kg, i.p.). Moreover, the reduction in the immobility time elicited by an effective dose of venlafaxine (8 mg/kg, i.p.) in the FST was prevented by the pretreatment of mice with the K⁺ channel openers cromakalim (10 µg/site, i.c.v.) and minoxidil (10 µg/site, i.c.v.). The drugs used in this study did not produce any change in locomotor activity.SignificanceThe results demonstrate that the neuromodulatory effects of venlafaxine, via the inhibition of K⁺ channels, are possibly involved in its anti-immobility activity in the mouse FST.     

Synthesis and biological evaluation of a series of benzoxazole/benzothiazole-containing 2,3-dihydrobenzo[b][1,4]dioxine derivatives as potential antidepressants

A series of benzoxazole/benzothiazole-2,3-dihydrobenzo[b][1,4]dioxine derivatives (5a–5d and 8a–8j) was synthesized. Compounds were evaluated for binding affinities at the 5-HT_1A and 5-HT_2A receptors. Antidepressant activities of the compounds were screened using the forced swimming test (FST) and the tail suspension test (TST). The results indicated that the compounds exhibited high affinities for the 5-HT_1A and 5-HT_2A receptors and showed a marked antidepressant-like activity. Compound 8g exhibited high affinities for the 5-HT_1A (K_i = 17 nM) and 5-HT_2A (K_i = 0.71 nM) receptors; it also produced a decrease of the immobility time and exhibited potent antidepressant-like effects in the FST and TST in mice.     

Effect of transcatheter renal arterial embolization combined with cryoablation on regulatory CD4+CD25+ T lymphocytes in the peripheral blood of patients with advanced renal carcinoma

ObjectiveTo analyze the effect of Argon-Helium cryosurgery (AHCS) combined with transcatheter renal arterial embolization (TRAE) on the differentiation of regulatory CD4⁺ CD25⁺ T cell (Treg) and its implication in patients with renal carcinoma.MethodsSeventy seven patients are included in the study, and divided into two groups: TRAE group (n = 45, receiving TRAE only) and TRAE + cryoablation group (n = 32, receiving cryoablation 2–3 weeks after TRAE). The percentage of Treg cells and T lymphocyte subsets (CD4⁺T, CD8⁺T, and CD4⁺T/CD8⁺T) in the peripheral blood is measured by flow cytometry previous to the therapy and 3 months after therapy. Meanwhile, the extent of tumor necrosis is measured by MRI or CT 1 month after therapy.ResultsThe percentages of Treg cells of patients in TRAE + cryoablation group decrease from (6.65 ± 1.22)% to (3.93 ± 1.16)%, (t = 42.768, P < 0.01), and the percentages of CD4⁺T and CD4⁺T/CD8⁺T increase significantly (P < 0.01). However, the results of patients in TRAE group show that the percentages of Treg, CD4⁺T, CD8⁺T and CD4⁺T/CD8⁺T increase slightly although the differences had no statistical significance (P > 0.05). The tumor necrosis rate of TRAE + cryoablation group is 57.5%, significantly higher than those of TRAE group, which shows 31.6% (t = 6.784, P < 0.01). The median survival duration of the TRAE + cryoablation group is 20 months, significantly longer than that of the TRAE group (χ² = 7.368, P < 0.01). The decreasing extent of Treg cells is correlated with tumor necrosis rates (r = 0.90, P < 0.01) and life time (r = 0.67, P < 0.01).ConclusionThe therapy of TRAE combined with cryoablation contributes to reduce the percentage of Treg cells and improve the immune situation of patients with renal cell carcinoma, which consequently increase tumor necrosis rate and prolong the patients‘ survival duration.     

Protective effect of heme oxygenase-1 induction against hepatic injury in alcoholic steatotic liver exposed to cold ischemia/reperfusion

AimsThe purpose of this study was to investigate the cytoprotective role of heme oxygenase-1 (HO-1) induction in hepatic injury in alcoholic steatotic liver exposed to cold ischemia/reperfusion (I/R).Main methodsAnimals were fed an ethanol liquid diet or isocaloric control diet for 5 weeks. Isolated perfused rat livers were preserved in Histidine–Tryptophan–Ketoglutarate at 4 °C. After 24 h of storage, livers were subjected to 120 min of reperfusion with Krebs–Henseleit bicarbonate buffer at 37 °C. Animals were pretreated with cobalt protoporphyrin (CoPP, 5 mg/kg, i.p.) or zinc protoporphyrin (ZnPP, 25 mg/kg, i.p.), HO-1 inducer and antagonist, respectively.Key findingsIn the model of ischemia/isolated perfusion, endogenous HO-1 was downregulated in the livers fed with ethanol diet (ED I/R). In ED I/R group, portal pressure and lactate dehydrogenase release were significantly increased, while bile output and hyaluronic acid clearance decreased compared to rats fed on control diet (CD I/R). Furthermore, hepatic glutathione content decreased and lipid peroxidation increased in the ED I/R group compared to the CD I/R group. These alterations were attenuated by upregulation of HO-1 with CoPP pretreatment.SignificanceOur results suggest that chronic ethanol consumption aggravates hepatic injury during cold I/R and it is likely due to downregulation of endogenous HO-1. Prior induction of HO-1 expression may provide a new strategy to protect livers against hepatic I/R injury or to increase the donor transplant pool through modulation of marginal alcoholic steatotic livers.     

Nebivolol regulates eNOS and iNOS expressions and alleviates oxidative stress in cerebral ischemia/reperfusion injury in rats

AimsOxidative stress-induced cell damage is reported to contribute to the pathogenesis of cerebral ischemia/reperfusion injury. This study investigated the neuroprotective effect of nebivolol against cerebral ischemia/reperfusion insult in rats.Main methodsThe model adopted was that of surgically-induced forebrain ischemia, performed by means of bilateral common carotid artery occlusion for 1 h, followed by reperfusion for 24 h. The effects of 5 and 10 mg/kg nebivolol, treated for 7 days prior to ischemia/reperfusion insult, were investigated by estimating endothelial and inducible nitric oxide synthases (eNOS and iNOS) protein expressions and assessing oxidative stress-related biochemical parameters in the rat forebrain. Also, infarct volume measurement and histopathological study of the forebrain were examined.Key findingsAdministration of nebivolol increased eNOS expression with simultaneous decrease in iNOS expression in a dose dependent manner. Moreover, nebivolol inhibited ischemia/reperfusion-induced depletion of reduced glutathione level and decreased the elevated total nitric oxide end production and malondialdehyde levels, superoxide dismutase and lactate dehydrogenase activities. A notable finding is that catalase activity was not changed in response to either ischemia/reperfusion insult or nebivolol treatment. However, the results confirmed that nebivolol significantly reduced infarct volume and alleviated ischemia/reperfusion-induced histopathological changes.SignificanceThe present study demonstrates the neuroprotective effect of nebivolol against cerebral ischemia/reperfusion insult. Neuroprotection observed with nebivolol may possibly be explained by regulating eNOS and iNOS expressions and by inhibition of oxidative stress-induced injury. Thus, nebivolol may be considered as a potential candidate for treatment in patients who are prone to stroke.