Adenosine Triphosphatase Activity Research Articles

Research on Fuzi based on animal thermotropism behavior to discover if it has fewer “hot” characteristics without Ganjiang

ObjectiveTo investigate whether Fuzi (Radix Aconiti Praeparata) has fewer “hot” characteristics when administered without Ganjiang (Rhizoma Zingiberis). MethodsDifferences in the thermotropism behaviors of mice treated either with Fuzi (Radix Aconiti Praeparata), Ganjiang (Rhizoma Zingiberis) or the combination of the two given intragastrically were investigated using the Animal Thermotropism Behavior Surveillance System. The water intake volume, oxygen consumption volume, adenosine triphosphatase (ATPase) activity, total antioxidant capacity (T-AOC) and total superoxide dismutase (T-SOD) activity were determined during the investigation. ResultsWhen Fuzi and Ganjiang were administered together, the rate at which mice remained on a warm plate (“remaining rate”) and the times and distances of their movement were all significantly reduced (P<0.05). Compared with the Normal group, the reduction was 55.1%, 48.3% and 44.8%, while compared with the Fuzi group, the reduction was 57.6%, 34.3% and 36.0%, indicating that “cold” tropism was significantly increased. Compared with the Normal and Fuzi groups, the ATPase activity and the respiratory oxygen consumption volume of the Fuzi + Ganjiang group were significantly increased (P<0.05), suggesting an improvement in energy metabolism and showing a “hot” characteristic when Fuzi and Ganjiang are present together. Additionally, the T-AOC and T-SOD activity were significantly enhanced (P<0.05). ConclusionThe behavior of mice tending toward “cold” tropism can be regarded as a quantitative reflection of Fuzi having fewer characteristics consistent w ith a “hot” nature when not used with Ganjiang, the functional mechanism of which may be a change in the ATPase activity in liver tissue.

Histochemical demonstration of five enzymes\' activities in Macrogyrodactylus clarii (Monogenea: Gyrodactylidae) from the catfish Clarias gariepinus

Histochemical techniques were applied to whole mounts, to study the distribution of the enzymes alkaline phosphatase, acid phosphatase, adenosine triphosphatase, 5'-nucleotidase and glucose-6-phosphatase in the organs and tissues of a viviparous monogenean, Macrogyrodactylus clarii Gussev, 1961, from the gills of the North African catfish Clarias gariepinus (Burchell) in Egypt. The following organs and tissues were studied: head region, anterior adhesive glands, mouth region, pharynx, intestine, testis, vesicula seminalis, male accessory gland, male accessory reservoir, copulatory organ, receptaculum seminis, egg-cell forming region, embryonic cells, excretory system, nerve cells, haptor, muscle fibres and subtegumental cell bodies (cytons). The enzymes showed marked differences in their activities among the studied organs and tissues. Alkaline phosphatase and acid phosphatase activities were detected in many organs and tissues, while the activities of adenosine triphosphatase, 5'-nucleotidase and glucose-6-phosphatase were restricted to a few organs. Although no positive reaction for any enzyme was observed in the anterior adhesive gland cells, a positive reaction for acid phosphatase was detected in the anterior adhesive areas. All enzymes showed marked activity in the digestive and excretory systems. The distribution of the enzymes in the tissues and organs of M clarii is compared with those of other monogeneans, including other gyrodactylids parasitizing the same host fish. Some possible functions of the enzymes are discussed.

D3 dopamine receptor regulation of D5 receptor expression and function in renal proximal tubule cells

Dopamine receptor, via D(1)-like and D(2)-like receptors, increases sodium excretion in kidney. We have reported positive interactions between D(3) and D(1) receptors in renal proximal tubule (RPT) cells. These reports, however do not preclude that there may be also interaction between D(3) and D(5) receptors, because of the lack of selective D(1) and D(5) receptor agonists or antagonists. We hypothesize that D(3) receptors can regulate D(5) receptors, and that D(3) receptor regulation of D(5) receptors in RPTs is impaired in spontaneously hypertensive rats (SHRs). It showed that a D(3) receptor agonist, PD128907, by the activation of protein kinase C activity, increased the expression of D(5) receptors in a concentration- and time-dependent manner in RPT cells from Wistar-Kyoto (WKY) rats. The stimulatory effect of the D(3) receptor on D(5) receptor expression was impaired in RPT cells from SHRs. The effect of D(3) receptor on D(5) receptor is functionally relevant; stimulation of D(5) receptor decreases Na(+)-K(+) adenosine triphosphatase (ATPase) activity in WKY cells. Pretreatment with D(3) receptor agonist for 24 h enhances the D(5) receptor expression and D(5) receptor-mediated inhibitory effect on Na(+)-K(+) ATPase activity in WKY cells, but decreases them in SHR cells. The effect of D(3) receptor on D(5) receptor expression and function was also confirmed in the D(5) receptor-transfected HEK293 cells. It indicates that activation of D(3) receptor increases D(5) receptor expression and function. Altered regulation of D(3) receptor on D(5) receptors may have a role in the pathogenesis of hypertension.

Muscle fiber types, growth and development in the whole myotome of cultured Pacific bluefin tuna Thunnus orientalis

Following the successful development of Pacific bluefin tuna (PBT) aquaculture, it is of considerable importance to determine the muscle fiber types and their growth patterns for future development. Muscle fiber profiles of dorsal ordinary, lateral ordinary (LO) and dark muscles and their growth patterns in PBT from 3.0 to 54.3 kg body weight were studied. Muscle fibers were histochemically stained for NADH-diaphorase and myosin adenosine triphosphatase activity (mATPase), and immunohistochemically stained with S-58 slow-muscle myosin antibody. All muscle fibers in dorsal and LO muscles showed low NADH-diaphorase activity, and acid-labile (pH 4.0 or 4.3) and alkali-stable mATPase activity. In LO muscle adjacent to dark muscle, three intensities of mATPase activity were observed after acid pre-incubation at pH 4.5 or 5.0, and the activity was related to the muscle fiber diameter. In dark muscle, all small and some large fibers stained intensely for NADH-diaphorase activity, related to their high aerobic metabolism. The high-active fibers with NADH-diaphorase in dark muscle were positive for S-58 antibody. Some large fibers in dark muscle showed intermediate NADH-diaphorase activity and high mATPase activity after alkali pre-incubations. These are fast-twitch oxido-glycolytic fibers in dark muscle and transformed to red muscle fibers with increasing body weight.

Combined treatment of HEDTA and propolis prevents aluminum induced toxicity in rats

A study was undertaken to evaluate protective effect of chelating agent, N-(2-hydroxy ethyl ethylene diamine triacetic acid) [HEDTA] with and without propolis against aluminum (Al) induced toxicity in liver, kidney and brain. Toxicity was induced by single administration of aluminum nitrate at a dose of 32.5mg/kg (½ of LD50). HEDTA (20mg/kg, ip), propolis (200mg/kg, po), and combination of HEDTA and propolis, respectively, were administered for 3days after 24h of Al exposure. Significant enhancement in AST, ALT, uric acid, urea, cholesterol, and triglyceride contents was found in serum, whereas albumin was decreased after Al exposure. Hepatic, renal, and neuronal LPO were found significantly increased after Al exposure, whereas it inhibited AChE activity in forebrain, midbrain, and hindbrain. Al significantly reduced the activity of adenosine triphosphatase, superoxide dismutase and catalase and GSH contents in hepatic, renal and nervous tissues. However, individual treatment of HEDTA and propolis restored biochemical parameters towards control but combined treatment of HEDTA and propolis offered better protection in comparison to monotherapy. Combined treatment of HEDTA and propolis preserved histological features, mitigated oxidative stress and improved liver, kidney and brain functions more profoundly.

Reversal of Carbon Tetrachloride-Induced Hepatic Injury by Aqueous Extract of Artemisia absinthium in Sprague-Dawley Rats

In the present study, we evaluated the protective activity of an aqueous extract of Artemisia absinthium against CCl4-induced hepatic damage in rats. The protective activity of this extract at three doses (2.5, 5, and 10 ml/ kg, once orally) against CCl4-induced oxidative damage (1.5 ml/kg, once intraperitoneally) in rats was analyzed. Various blood and tissue biochemical studies were performed, and the administration of the toxicant significantly altered blood biochemical variables. Hepatic lipid peroxidation (LPO) was significantly elevated, whereas glutathione (GSH) level was considerable depleted after intoxication. Remarkable decreases in the activities of adenosine triphosphatase (ATPase) and glucose-6-phosphatase (G-6-Pase) after intoxication were observed. Treatment with all three doses reversed altered tissue biochemical values, but the greatest protection was observed at the lowest dose (2.5 ml/kg). The results of this study show that A. absinthium induces strong hepatoprotective activity. It decreased the hexobarbitone-induced sleep time and improved cholerectic activity (bile flow and bile solids) and excretory capacity, and it also stimulated bile secretion. The potent antioxidant activity of A. absinthium was indicated by scavenging effects on 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and hydrogen peroxide (H2O2). Thus, be considered for use in reducing hepatic damage and may serve as an alternative medicine in hepatic etiologies.

Mitochondrial Filamentation: Some Methods of Isolation and Assay

Working transiently but recurrently, during more than 40 years we managed to achieve the isolation of cellular mitochondria by differential centrifugation with less mechanical, thermal and chemical trauma; mostly from rodents' livers, kidneys and brains, and principally at moments of deep rest. The mitochondria present new substructures: filaments, cones and veils. Filamented mitochondria have different rates of oxidative phosphorylation loss, adenosine triphosphatase activity and glycolysis compartmentalization. These preliminary findings could pave the way towards a more physiological consideration of mitochondria and represent important steps forward for an understanding of the nature, cause and treatment of very serious diseases among which we can count cancer and neural degeneration. The initial considerations of a deeper understanding of planetary life oxygen and physiological and metabolic death are also in sight.

Effects of Nifedipine on Cation Transport and Na - K-ATPase Activity in Erythrocytes and Electrolyte Homeostasis in Rats

Calcium channel antagonists have been reported to reduce blood pressure in those individuals at risk of cardiac and cerebrovascular events. There is no specific study available regarding the role of electrolyte alterations in blood pressure lowering effects of nifedipine. The present study was designed to investigate the role of electrolyte homeostasis, changes in ouabain-sensitive Na+ K+ adenosine triphosphatase (ATPase) activity, and net sodium efflux and potassium influx across blood cell membranes. Rats were divided into two experimental groups . Nifedipine (20mg/ kg body weight ) was administered by gastric tube to the test group . Control group received same volume of deionize water .The intra-erythrocyte sodium, serum sodium, potassium, calcium and sodium, calcium content of heart and kidney tissues were decreased significantly. Whereas, intra-erythrocyte potassium was slightly decreased or remained normal in nifedipine treated rats as compared to normal healthy rats. The Na - K - ATPase activity, serum magnesium, potassium and magnesium content in heart and kidney tissues were increased significantly. Results confirmed that nifedipine represses ion channels, transporters and calcium-binding proteins in tissues. Erythrocyte studies indicate that nifedipine blocks the entrance of calcium into the cells but also stimulate Na - K - ATPase activity, resulting in reduction of intracellular sodium concentration, thus suggesting direct nifedipine-induced blood pressure reduction.

Histochemical Studies on The Palatine Tonsils of Sheep(Ovis aries)

Tissue pieces from the oropharynx for the palatine tonsil from different prenatal and postnatal age groups of sheep were collected from Corporation slaughter house, Perambur, Chennai. Mild activity to periodic acid Schiff (PAS) reaction was observed in the tonsillar tissue of all the age groups of sheep. The mucous glands at the palatine tonsil showed strong PAS positive reaction. A strong alkaline phosphatase activity was observed in the parafollicular areas and crypt epithelium. An intense activity of acid phospahatase was observed in the parafollicular or interfollicular regions, whereas the crypt epithelium showed mild activity. Strong reaction of adenosine triphosphatase activity was noticed around the tonsillar follicles and a mild reaction was observed in the interfollicular regions. The activity of 5’ nucleotidase was intense in the tonsillar follicles and a mild activity of the enzyme was noticed in the interfollicular region.

Elevated intracellular Ca2+ reveals a functional membrane nucleotide pool in intact human red blood cells

Elevated intracellular calcium generates rapid, profound, and irreversible changes in the nucleotide metabolism of human red blood cells (RBCs), triggered by the adenosine triphosphatase (ATPase) activity of the powerful plasma membrane calcium pump (PMCA). In the absence of glycolytic substrates, Ca2+-induced nucleotide changes are thought to be determined by the interaction between PMCA ATPase, adenylate kinase, and AMP-deaminase enzymes, but the extent to which this three-enzyme system can account for the Ca2+-induced effects has not been investigated in detail before. Such a study requires the formulation of a model incorporating the known kinetics of the three-enzyme system and a direct comparison between its predictions and precise measurements of the Ca2+-induced nucleotide changes, a precision not available from earlier studies. Using state-of-the-art high-performance liquid chromatography, we measured the changes in the RBC contents of ATP, ADP, AMP, and IMP during the first 35 min after ionophore-induced pump-saturating Ca2+ loads in the absence of glycolytic substrates. Comparison between measured and model-predicted changes revealed that for good fits it was necessary to assume mean ATPase Vmax values much higher than those ever measured by PMCA-mediated Ca2+ extrusion. These results suggest that the local nucleotide concentrations generated by ATPase activity at the inner membrane surface differed substantially from those measured in bulk cell extracts, supporting previous evidence for the existence of a submembrane microdomain with a distinct nucleotide metabolism.

Therapeutic role of terbutaline in a rat whole-lung lavage model

ABSTRACTWhole-lung lavage (WLL) is the preferred therapy for patients with pulmonary alveolar proteinosis (PAP). However, WLL can cause fluid retention, surfactant lost, and hypoxia. Terbutaline has been shown to accelerate the rate of alveolar fluid clearance and augment surfactant secretion. The present study aimed at investigating effects of terbutaline and oxygen ventilation in rats with WLL. Forty rats were randomly divided into control, ventilation, NS (normal saline) + ventilation, LT (terbutaline in low concentration, 10−4 M) + ventilation, and HT (terbutaline in high concentration, 10−3 M) + ventilation groups. The left thoracic cavity was opened and a cannula was inserted into the left bronchus. The left lung was ventilated, while the right lung was lavaged. Arterial blood gas, electrocardiogram, histological changes, and wet/dry ratio of lung tissues were examined. The concentrations of total protein (TP), total phospholipids (TPL), and disaturated phosphatidylcholine (DSPC) in recovery fluid were measured. For the in vitro study, alveolar type II (ATII) cells were isolated from healthy male rats, incubated for 24 hours, and divided into control, LT, and HT groups and exposed to different concentration of terbutaline (10−4 and 10−3 M) for 2 hours, followed by measuring sodium-potassium adenosine triphosphatase (Na+,K+-ATPase) activity. Oxygen ventilation significantly increased Pao2/Fio2 after lavage in the ventilation group, as compared to control group (249.4 ± 7.9 vs 210.6 ± 9.4; P = .001). Compared with NS + venlitation group, a higher concentration of terbutaline decreased the wet/dry ratio of lung tissues (5.0 ± 0.1 vs 5.6 ± 0.1; P = .007), increased the concentrations of TPL (175.9 ± 14.0 vs 162.0 ± 6.8 mg/L; P = .031) and DSPC (93.2 ± 6.9 vs 70.9 ± 6.2 mg/L, P = .0001) in the recovery fluid, and alleviated hypoxia significantly. Terbutaline in both low and high doses increased Na+,K+-ATPase activity in ATII cells (62.5 ± 2.4 and 62.6 ± 2.8 vs 32.2 ± 2.1 mmol/h/mg protein; P < .01). Theses results show that the administration of terbutaline facilitates alveolar fluid absorption and increases surfactant secretion during lung lavage, the former is partly driven by increasing Na+,K+-ATPase activity. The modified lavage method, with the use of terbutaline and oxygen ventilation, is one of potential therapies for patients with PAP.

Anti-hypoxic activity at simulated high altitude was isolated in petroleum ether extract of Saussurea involucrata

Ethnopharmacological relevanceRhodiola algida, Saussurea involucrata, and other herbs grown in Qinghai-Tibetan plateau have long been used to prevent and treat acute mountain sickness. Aim of the studyTo screen and identify the anti-hypoxic constituents in the herbs grown in Qinghai-Tibetan plateau of Northwestern China. Materials and methodsThe anti-hypoxic activities of 20 selected plateau herbs were examined against two positive controls, Rhodiola algida and acetazolamide, using the normobaric hypoxia model of mice. The herb with the highest activity was successively extracted with 70% ethanol, petroleum ether, chloroform, ethyl acetate and n-butanol. The extract with the highest activity was identified by comparing the survival time of mice under normobaric hypoxia condition after being subjected to different extracts. The identified extract was further tested by simulating high altitudes through an acute decompression model and a chronic decompression model for mice. ResultsThe herb found to have the highest anti-hypoxic activity was Saussurea involucrate (Kar. et Kir.) Sch.-Bip, and the most effective fraction was in the petroleum ether extract. Administration of petroleum ether extract of Saussurea involucrata (PESI) to mice at 50mg/kg significantly decreased the mortality of animals under acute decompression conditions. Changes in biochemical indicators for glycometabolism and energy metabolism, including adenosine triphosphate (ATP) content and adenosine triphosphatase (ATPase) activity in brain and cardiac muscle, lactic acid (LAC) and lactate dehydrogenase (LDH) in blood and cardiac muscles, blood sugar, and glycogen content in liver and skeletal muscle were reversed under chronic decompression conditions. ConclusionsSaussurea involucrata (Kar. et Kir.) Sch.-Bip exhibits high anti-hypoxic activity that may be effective in preventing acute mountain sickness, and the active constituents are mainly in the petroleum ether extract.

Propolis Prevents Hepatorenal Injury Induced by Chronic Exposure to Carbon Tetrachloride

Carbon tetrachloride (CCl4) is a well-known hepatotoxicant, and its exposure induces hepatorenal injury via oxidative stress and biochemical alterations. This study had been conducted to confirm the protective role of propolis extract on CCl4-induced hepatorenal oxidative stress and resultant injury. Propolis extracts collected from Gwalior district and 24 female Sprague Dawley rats were used for experiment. Animals were exposed to CCl4 (0.15 mL/kg, i.p.) for 12 weeks (5 days/week) followed by treatment with propolis extract (200 mg/kg, p.o.) for consecutive 2 weeks. CCl4 exposure significantly depleted blood sugar and hemoglobin level and raised the level of transaminases, alkaline phosphatase, lactate dehydrogenase, protein, urea, albumin, bilirubin, creatinine, triglycerides, and cholesterol in serum. Lipid peroxidation was enhanced, whereas GSH was decreased significantly in liver and kidney in CCl4-intoxicated group. Ethanolic extract of propolis successfully prevented these alterations in experimental animals. Activities of catalase, adenosine triphosphatase, glucose-6-phosphatase, acid, and alkaline phosphatase were also maintained towards normal with propolis therapy. Light microscopical studies showed considerable protection in liver and kidney with propolis treatment, thus, substantiated biochemical observations. This study confirmed hepatoprotective potential of propolis extract against chronic injury induced by CCl4 by regulating antioxidative defense activities.

The influence of PAMAM-OH dendrimers on the activity of human erythrocytes ATPases

Dendrimers are a relatively new and still not fully examined group of polybranched polymers. In this study polyamidoamine dendrimers with hydroxyl surface groups (PAMAM-OH) of third, fourth and fifth generation (G3, G4 and G5) were examined for their ability to influence the activity of human erythrocyte plasma membrane adenosinetriphosphatases (ATPases). Plasma membrane ATPases are a group of enzymes related, among others, to the maintenance of ionic balance inside the cell. An inhibition of their activity may result in a disturbance of cell functioning. Two of examined dendrimers (G4 and G5) were found to inhibit the activity of Na+/K+ ATPase and Ca2+ ATPase by 20–30%. The observed effect was diminished when higher concentrations of dendrimers were used. The experiment with the use of pyrene as fluorescent probe sensitive to the changes in microenvironment's polarity revealed that it was an effect of dendrimers' self-aggregation. Additional studies showed that PAMAM-OH dendrimers were able to decrease the fluidity of human erythrocytes plasma membrane. Obtained results suggest that change in plasma membrane fluidity was not caused by the dendrimer–lipid interaction, but dendrimer–protein interaction. Different pattern of influence of dendrimers on ATPases activity and erythrocyte membrane fluidity suggests that observed change in ATPases activity is not a result of dendrimer–lipid interaction, but may be related to direct interaction between dendrimers and ATPases.

Pretreatment with morin, a flavonoid, ameliorates adenosine triphosphatases and glycoproteins in isoproterenol-induced myocardial infarction in rats

The aim of this investigation was to evaluate the preventive role of morin, a flavonoid, on cardiac marker enzymes such as aspartate transaminase, lactate dehydrogenase, creatine kinase and creatine kinase-MB, membrane-bound enzymes such as sodium potassium-dependent adenosine triphosphatase, calcium-dependent adenosine triphosphatase and magnesium-dependent adenosine triphosphatase, and glycoproteins such as hexose, hexosamine, fucose and sialic acid in isoproterenol (ISO)-induced myocardial infarction (MI) in rats. Male albino Wistar rats were pretreated with morin (20, 40 and 80 mg/kg) daily for a period of 30 days. After the treatment period, ISO (85 mg/kg) was subcutaneously injected into the rats at an interval of 24 h for 2 days. ISO-induced rats showed significantly (P < 0.05) increased activities of cardiac marker enzymes in serum and decreased activities in the heart, and increased activities of calcium-dependent adenosine triphosphatase and magnesium-dependent adenosine triphosphatase in the heart, and the activity of sodium potassium-dependent adenosine triphosphatase decreased in the heart. ISO induction also showed a significant increase in the levels of glycoproteins in serum and the heart. Pretreatment with morin (40 mg/kg) daily for a period of 30 days exhibited significant (P < 0.05) effects and altered these biochemical parameters positively compared to the other two doses. Thus, our study shows that morin has a protective role in ISO-induced MI in rats. The observed effects might be due to the free radical-scavenging, antioxidant and membrane-stabilising properties of morin.

Deltamethrin induced alterations of hematological and biochemical parameters in fingerlings of Catla catla (Ham.) and their amelioration by dietary supplement of vitamin C

The present study was carried out to investigate the sub-lethal toxicity of technical grade deltamethrin (a synthetic pyrethroid) of concentration 1.61 μg/L (1/3rd of 96 h LC 50) on hematological and biochemical parameters of catla ( Catla catla) fingerlings and its amelioration through dietary vitamin C. The deltamethrin exposed fishes were fed with different levels of supplemented vitamin C such as 50, 250, 500 and 1000 mg/kg diet to see its ameliorating effect by assaying hematological parameters viz. total erythrocyte count (TEC), total leukocyte count (TLC), hemoglobin content (Hb), total serum protein, albumin, globulin, albumin–globulin ratio and biochemical parameters such as lactate dehydrogenase (LDH), acetylcholine esterase (AChE), alanine amino transferase (ALT), aspartate amino transferase (AST), total adenosine triphosphatase (ATPase), magnesium adenosine triphosphatase (Mg 2+-ATPase) and sodium potassium adenosine triphosphatase (Na +, K +-ATPase) activities. The finding of this study showed that deltamethrin had negative effect on the hematological and biochemical parameters of Catla catla. The experimental group, which was exposed to deltamethrin and fed with normal diet showed significantly lower values ( P ⩽ 0.05) of all parameters studied except ALT activity. This might be due to possible disruption of hematopoiesis and proteosynthesis. However, the fish fed with varied concentration of vitamin C in diets neutralized the toxic effect of deltamethrin, as evidenced by significantly lowered hematological and biochemical response. Vitamin C @ 1000 mg/kg diet was the most effective in amelioration of harmful effect of deltamethrin on hematological and biochemical parameters of catla fingerlings. The result suggests that vitamin C can be effectively used to neutralize the toxic effect of deltamethrin on catla.

Crystal Structure of the Maltose Transporter in a Pretranslocation Intermediate State

Adenosine triphosphate (ATP)-binding cassette (ABC) transporters convert chemical energy from ATP hydrolysis to mechanical work for substrate translocation. They function by alternating between two states, exposing the substrate-binding site to either side of the membrane. A key question that remains to be addressed is how substrates initiate the transport cycle. Using x-ray crystallography, we have captured the maltose transporter in an intermediate step between the inward- and outward-facing states. We show that interactions with substrate-loaded maltose-binding protein in the periplasm induce a partial closure of the MalK dimer in the cytoplasm. ATP binding to this conformation then promotes progression to the outward-facing state. These results, interpreted in light of biochemical and functional studies, provide a structural basis to understand allosteric communication in ABC transporters.

The Mechanism of Spleen Injury in Rabbits with Acute Renal Failure

Immune function disorders are common during acute renal failure (ARF), but the mechanisms are unknown. As the spleen is the largest organ of the immune system, we aimed to observe if there are morphological changes in the spleen in rabbits with ARF. In addition, we tried to explore its mechanism from the perspective of oxygen free radicals, nitric oxide (NO), myeloperoxidase (MPO), and membrane pump activities. ARF animal models were established by either hypodermic injection of 1.3 mL/kg bw 1% HgCl2 or intramuscular injection of 10 mL/kg bw 50% glycerin. Animals were divided into 12 h, 24 h, and 48 h treatment groups with six rabbits in each group. Compared with control animals, congestion was found in the spleen and splenic trabeculae were increased in the two ARF model groups at multiple time points. The malonaldehyde, NO, nitric oxide synthase, and MPO levels in the ARF models were increased compared with the control group at 24 h or 48 h, and the superoxide dismutase and adenosine triphosphatase activities were significantly lower than the levels in the control group at multiple time points. These indices of free radical damage were induced gradually with ARF development, and there were statistically significant differences at different time points. These data suggested that histological damage of spleen during ARF may lead to immune disorders, which might be related to free radical injury, NO excessive release, polymorphonuclear neutrophils (PMN) sequestration, and membrane pump dysfunction.

The Influence of Lead on Different Proteins in Gill Cells From the Freshwater Bivalve, Corbicula fluminea, From Defense to Repair Biomarkers

The objective of this study was to evaluate the influence of lead (Pb) on regulatory proteins linked to mechanisms of animal adaptation to polluted environments (using in vivo and in vitro tests) and to validate the in vitro assay as a tool for environmental assessment. Specimens of the bivalve Corbicula fluminea were exposed to nominal concentrations of Pb 5 mg l(-1) for 96 h. Isolated gill cells were exposed to three concentrations (1, 10, and 100 μM) for 5 h. Metal toxicity was evaluated by cell viability (trypan blue exclusion). We also analyzed Na+/K+ adenosine triphosphatase (ATPase) and carbonic anhydrase activity. Additionally, the multixenobiotic-resistance (MXR) phenotype was evaluated by the accumulation of rhodamine B (RB). Immunolabeling was used to quantify the expression of P-glycoproteins (C219) and proteins involved in ion transport, water movement, and cellular repair using antibodies against Na+/K+ ATPase, aquaporin 1, and heat-shock protein 70 (Hsp70). Pb was shown to be toxic in both in vivo and in vitro tests, in which cellular viability significantly decreased by approximately 25%. Cellular viability in the in vivo assays was determined by gill cell isolation after the entire animal was exposed to Pb. We observed that Na+/K+ ATPase activity was inhibited by 70%. Also, the expression of the MXR phenotype significantly increased in our in vivo tests. A statistically significant difference was observed in the expression of all proteins in the in vitro assays, whereas only Hsp70 increased in vivo. Employing these analyses, we could validate the sensitivity of the in vitro tests and can propose our in vitro model as a possible tool for environmental assessment.

Decreased neuronal Na+,K+-ATPase activity inAtp1a3heterozygous mice increases susceptibility to depression-like endophenotypes by chronic variable stress

Unipolar depression and bipolar depression are prevalent and debilitating diseases in need of effective novel treatments. It is becoming increasingly evident that depressive disorders manifest from a combination of inherited susceptibility genes and environmental stress. Genetic mutations resulting in decreased neuronal Na(+) ,K(+) -ATPase (sodium-potassium adenosine triphosphatase) activity may put individuals at risk for depression given that decreased Na(+) ,K(+) -ATPase activity is observed in depressive disorders and animal models of depression. Here, we show that Na(+) ,K(+) -ATPase α3 heterozygous mice (Atp1a3(+/-) ), with 15% reduced neuronal Na(+) ,K(+) -ATPase activity, are vulnerable to develop increased depression-like endophenotypes in a chronic variable stress (CVS) paradigm compared to wild-type littermates (Atp1a3(+/+) ). In Atp1a3(+/+) mice CVS did not decrease Na(+) ,K(+) -ATPase activity, however led to despair-like behavior in the tail suspension test (TST), anhedonia in a sucrose preference test and a minimal decrease in sociability, whereas in Atp1a3(+/-) mice CVS decreased neuronal Na(+) ,K(+) -ATPase activity to 33% of wild-type levels, induced despair-like behavior in the TST, anhedonia in a sucrose preference test, anxiety in the elevated plus maze, a memory deficit in a novel object recognition task and sociability deficits in a social interaction test. We found that a mutation that decreases neuronal Na(+) ,K(+) -ATPase activity interacts with stress to exacerbate depression. Furthermore, we observed an interesting correlation between Na(+) ,K(+) -ATPase activity and mood that may relate to both unipolar depression and bipolar disorder. Pharmaceuticals that increase Na(+) ,K(+) -ATPase activity or block endogenous Na(+) , K(+) -ATPase inhibition may provide effective treatment for depressive disorders and preclude depression in susceptible individuals.