Effects of two-vessel forebrain ischemia and of administration of indomethacin and quinacrine on Na<Superscript>+</Superscript>, K<Superscript>+</Superscript>-ATPase activity in various rat brain areas

The effect of a two-vessel forebrain ischemia (induced by occlusion of carotid arteries and hypotension), subsequent reperfusion, and administration of indomethacin and quinacrine on the Na⁺,K⁺-ATPase activity and diene conjugate content was studied in various rat forebrain fields. The most pronounced metabolic alterations were observed during ischemia and reperfusion. Under these effects, there was a statistically significant reduction of the Na⁺,K⁺-ATPase activity in the brain cortex and striatum and an increase of the diene conjugate content in the rat brain cortex in comparison with sham-operated animals. Injection of indomethacin, a cyclooxygenase inhibitor, to rats subjected to ischemia and reperfusion, resulted to a statistically significant increase of the Na⁺,K⁺-ATPase activity in the brain cortex, hippocampus, and striatum (p < 0.02) as compared with control animals. The diene conjugate content in the rat brain cortex during brain ischemia and reperfusion was statistically significantly lower in the rats injected with indomethacin. The effect of quinacrine (a blocker of phospholipase A₂) was similar to that of indomethacin in the rat cortex, whereas in the rat striatum and hippocampus, the quinacrine effect during ischemia and reperfusion was less marked than that of indomethacin. The obtained data indicate the ability of inhibitors of the arachidonic pathway of free radical formation to normalize the Na⁺, K⁺-ATPase activity during brain ischemia. There also revealed local peculiarities of metabolic disturbances in different regions of the rat forebrain during ischemia and reperfusion.Translated from Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, Vol. 41, No. 1, 2005, pp. 33–38.Original Russian Text Copyright © 2005 by Molchanova, Moskvin, Zakharova, Yurlova, Nosova, Avrova.     

Effect of Propionyl-L-Carnitine On Rat Spinal Cord Ischaemia and Post-Ischaemic Reperfusion Injury

In this study we have examined the effect of propionyl-L-carnitine (PC) on rat spinal cord ischaemia and post-ischaemic reperfusion injury by evaluating two lipid peroxidation indices, thiobarbituric acid reactive substances (TBARS) and diene conjugation, before and after the addition of an ADP-Fe⁺² complex to spinal cord homogenates. Aerobic, ischaemic, and post ischaemic reperfusion rat spinal cord homogenates from PC treated and untreated animals did not show any statistically significant difference in their TBARS and conjugated diene content. The addition of the ADP-Fe⁺² complex to these homogenates resulted in an increased production of both the lipid peroxidation indices, though the magnitude of such formation was related to the type of experimental intervention. The post-ischaemic reperfusion samples of untreated rats showed the highest TBARS and conjugated diene content, while ischaemic samples in either treated and untreated rats did not show any statistically significant difference with respect to the aerobic samples. The post-ischaemic reperfusion samples of treated rats showed a statistically significant decrease of TBARS and conjugated diene production in comparison to the untreated samples. In addition, PC was also able to partially inhibit TBARS and conjugated diene formation in linoleic acid micelles exposed to hemoglobin, though it did not protect albumin fragmentation from the irradiation of water with an X-ray source.     

Increase in cellular pool of low-molecular-weight iron during ethanol metabolism in rat hepatocyte cultures

Ethanol-induced lipid peroxidation was studied in primary rat hepatocyte cultures supplemented with ethanol at the concentration of 50 mM. Lipid peroxidation was assessed by two indices: (1) conjugated dienes by second-derivative UV spectroscopy in lipid extract of hepatocytes (intracellular content), and (2) free malondialdehyde (MDA) by HPLC-UV detection and quantitation for the incubation medium (extracellular content). In cultures supplemented with ethanol, free MDA increased significantly in culture media, whereas no elevation of conjugated diene level was observed in the corresponding hepatocytes. The cellular pool of low-mol-wt (LMW) iron was also evaluated in the hepatocytes using an electron spin resonance procedure. An early increase of intracellular LMW iron (≤1 hr) was observed in ethanol-supplemented cultures; it was inhibited by 4-methylpyrazole, an inhibitor of alcohol dehydrogenase, whereas α-tocopherol, which prevented lipid peroxidation, did not inhibit the increase of LMW iron. Therefore, the LMW iron elevation was the result of ethanol metabolism and was not secondarily induced by lipid hydroperoxides. Thus, ethanol caused lipid peroxidation in rat hepatocytes as shown by the increase of free MDA, although no conjugated diene elevation was detected. During ethanol metabolism, an increase in cellular LMW iron was observed that could enhance conjugated diene degradation.     

Day-night variations in pro-oxidant reactions of hypothalamic,hepatic and pancreatic tissue in mice with spontaneous obesity (Neotomodon alstoni)

Objectives: The present work compares the pro-oxidant properties in hypothalamic, hepatic, and pancreatic tissue of spontaneously obese and lean Neotomodon alstoni during day and night. Methods: Lipid peroxidation from hypothalamus, liver, and pancreas from lean and obese mice were quantified by the two-thiobarbituric acid method. Lipid peroxidation in vivo was also determined by means of detection of conjugated dienes in lipid extracts. Results: Hypothalamic tissue from obese Neotomodon showed a notorious increase (nearly 700%) in the production of thiobarbituric acid-reactive substances (TBARS) at day, either in basal as well as in an assay supplemented with Fe²⁺; the presence of conjugated dienes was also notably greater (76%) at day. Hypothalamus of lean mice presented an increase (170%) in assay supplemented with Fe²⁺. Hepatic tissue in obese mice showed diurnal increasing in TBARS + Fe²⁺ (34%) and in conjugated dienes (38%), while lean mice showed only a diurnal increase (45%) in TBARS + Fe²⁺. Pancreatic tissue from obese mice presented a diurnal increasing in basal TBARS (130%) but a decrease (72%) in TBARS + Fe²⁺. Presence of conjugated dienes was also decreased during the day in lean (60%) and in obese (40%) mice. Conclusions: In the obese Neotomodon, there is a larger day–night change in pro-oxidant status in the hypothalamus and in pancreas than the one observed in the liver, suggesting a differential equilibrium between oxidative reactions and antioxidant defenses in the different tissues during the day–night cycle.     

Chronic taurine supplementation ameliorates oxidative stress and Na+ K+ ATPase impairment in the retina of diabetic rats

Summary.  This study evaluates the effect of 4 months supplementation with 2% and 5% taurine (w/w) on the retina of diabetic rats. In non-diabetic rats, taurine does not modify glycemia, body weight, retinal conjugated dienes (CD), lipid hydroperoxide (LP), and Na⁺K⁺ATPase activity. In diabetic rat, at 2, 4, 8, 16 weeks following the onset of diabetes, retinal CD and LP are significantly and progressively increased, while pump activity is gradually and significantly reduced. In taurine supplemented diabetic rats, glycemia is not affected but lipid peroxidation is significantly decreased. Finally, taurine preserves ATPase activity being 5% more effective than 2% taurine. We conclude that taurine supplementation ameliorates biochemical retinal abnormalities caused by diabetes, thereby suggesting that taurine may have a role in the prevention of retinal changes in diabetes. Received November 26, 2001 Accepted January 10, 2002 Published online October 3, 2002 Authors' address: Prof. Flavia Franconi, Department of Pharmacology, University of Sassari, Via Muroni 23a, I-07100 Sassari, Italy, Fax: 39-79228715, E-mail: franconi@ssmain.uniss.it     

不同声强超声对孕鼠子宫收缩及胎鼠神经损伤的影响及机制

目的:探讨不同声强超声对孕鼠子宫收缩及胎鼠神经损伤的影响及机制。方法:将32只孕鼠随机分为A(0)组、B(2)组、C(4)组、D(8)组,每组各8只,分别接受声强为0 W cm~(-2)、2 W cm~(-2)、4 W cm~(-2)和8 W cm~(-2)的超声辐照20 min。记录孕鼠子宫收缩及子宫平滑肌ATP酶的活力,检测胎鼠大脑皮层与海马神经元凋亡及胆碱能神经系统相关酶的活力。结果:超声增加孕鼠子宫收缩频率、收缩幅度、收缩张力和子宫活动度(P均0.05),降低孕鼠子宫平滑肌中钠钾ATP酶、钙ATP酶和钙镁ATP酶的活性(P均0.05)。超声降低胎鼠大脑皮层和海马中Bcl~(-2)水平(P0.05),增加Bax和Caspase-3水平(P均0.05)。以及促进乙酰胆碱酯酶活力,降低乙酰胆碱和乙酰胆碱转移酶水平(P均0.05)。且4 W cm~(-2)和8 W cm~(-2)的超声比2 W cm~(-2)超声对这些指标的作用更强。结论:4 W cm~(-2)和8 W cm~(-2)超声可能通过降低ATP酶的活性促进孕鼠子宫平滑肌收缩,并可引起胎鼠大脑皮层和海马神经元损伤,机制可能与胆碱能神经元系统失衡有关,2 W cm~(-2)声强的超声对胎鼠神经元损伤甚小。     

Distribution of l-Leucine-pyruvate Transaminase in Bacteria

Dodecadien-1-ols, tetradecadien-1-ols and hexadecadien-1-ols with a conjugated (E,E)- or (E)-diene system between the ωl,ω3- and ω5, ω7-positions, their acetates, and aldeh?de derivatives (lepidopterous sex pheromones and candidates) were analyzed by electron impact mass spectrometry, which was operated at 70 eV ionization voltage. Three functional derivatives with a same diene system presented a similar spectral pattern, except for the molecular ions (M⁺), [M ? H₂O]⁺ of the alcohols and [M ? CH₃CO₂H]⁺ of the acetates. Each isomer showed a characteristic fragment ion series of C_nH_2n?2⁺ ~C_nH_2n?5⁺ (C₄~C₉), which reflected the double-bond position in the molecule, indicating a method for determining the position of a natural diene pheromone by comparing its mass spectrum with those of the synthetic dienes. By this method, the natural pheromone of Hellula undalis was confirmed to be a ω3, ω5-diene. Furthermore, the fitness indexes proposed by Kuwahara et al. were calculated for some pheromone components, using the mass spectra of synthetic dienes, in order to examine the possibility and limitation for applications of those mass spectra to natural pheromone studies.     

Hormonal Regulation of Ca2+ Stimulated K+ Influx and Ca2+, K+- ATPase in Rice Roots: in vivo and in vitro Effects of Auxins and Reconstitution of the ATPase

The role of natural and synthetic auxins in regulation of ion transport and ATPase activity was studied in rice roots (Oryza sativa L. cv. Dunghan Shah). In vivo treatment of seedlings with 2,4-dichlorophenoxyacetic acid at 2 × 10^?6M for a short period enhanced subsequent Ca²⁺ stimulated K⁺ influx and ATPase activity, while a longer treatment diminished both K⁺ influx and ATPase activity. Indoleacetic acid at 10^?10–10^?8M induced ATPase activity. In in vitro experiments both 2,4-dichloro phenoxyacetic acid and indoleacetic acid (10^?10–10^?8M) stimulated Ca²⁺, K⁺-ATPase activity of a plasmalemma rich micro somal fraction from the roots. Acetone extracted ATPase preparations lost their activity. The enzyme regained its activity and its sensitivity towards ions (Ca²⁺+ K⁺) when reconstituted with phosphatidyl choline. Addition of auxins also indicated that the presence of the lipid was necessary in the interaction between the ATPase and auxins. Auxins and ions probably interact with the intact ATPase lipoprotein complex, which may possess a receptor site for the auxins, possibly as a sub unit.     

Reaction of ozone with phospholipid vesicles and human erythrocyte ghosts

Phospholipid vesicles (unilamellar) and liposomes (multilamellar) made from egg phosphatidylcholine reacted similarly with ozone, producing hydrogen peroxide and malonaldehyde. On the basis of amount of ozone reacted, there was a 20% yield of hydrogen peroxide and 2.4% yield of malonaldehyde. The reactivity of the egg phosphatidylcholine membranes was a function of exposed membrane surface area. Large amounts of ozone caused no change in erythrocyte ghost phospholipid, fatty acid, or cholesterol composition. Thiobarbituric acid-positive material and conjugated dienes were present in very small quantities, suggesting some lipid oxidation which was below the limits of chromatographic detection. Ozone inhibited glyceraldehyde 3-phosphate dehydrogenase more than (Na⁺ + K⁺) adenosine triphosphate in exposed unsealed erythrocyte ghosts. The (Na⁺ + K⁺) adenosine triphosphatase activity sensitive to ozone was the ouabain-insensitive activity. Acetylcholinesterase activity was not significantly inhibited.     

Angiotensin increases microsomal (Na−K-ATPase activity in several tissues

Angiotensin increased microsomal (Na⁺K⁺)-activated ATPase from rat hypothalamus, mucosa of colon and bovine adrenal cortex but not brain cortex. Angiotensin did not change significantly Mg²⁺-ATPase in these tissues. Enhancement by angiotensin was evident at concentrations of 10⁻⁸ − 10⁻¹² M. In bovine adrenal cortex angiotensin increased ATPase activity in the outer and not in the inner layer. Angiotensin increased ATPase activity with Na⁺ above 20 mM and K⁺ above 5 mM present simultaneously, but not with either ion alone.     

Comparison of lipid effects on K+-Mg2+ activated p-nitrophenyl phosphatase and Na+-K+-Mg2+ activated adenosine triphosphatase of membrane

Abstract— A comparison was made between K⁺-Mg²⁺ activated p-nitrophenyl phosphatase and Na⁺-K⁺-Mg²⁺ activated adenosine triphosphatase with a solubilized enzyme preparation from a membrane fraction of cerebral cortex. The NPPase showed activity even in the absence of phospholipid, whereas the ATPase required the lipid for its activity. More varied types of phospholipids were effective in activating the NPPase than the ATPase, and with each phospholipid the extent and the pattern of the NPPase activation differed from that of the ATPase. By deoxycholate treatment the pH optimum of the NPPase was shifted independently from the pH optimum shift of the ATPase. The specific activity ratio of the NPPase to the ATPase was not constant during purification. These two enzymes were, however, not separable with ammonium sulphate fractionation, and their thermo-lability was identical regardless of the presence of phospholipid. The results suggested two possibilities: (1) the NPPase is a separate enzyme entity from the ATPase; (2) although the NPPase is a part of the ATPase system, the mechanism of action of lipids on the former part differs from that on the rest of the system.     

Effect of partial ischemia on phospholipids and postischemic lipid peroxidation in rabbit spinal cord

Rabbit spinal cord, subjected to severe partial ischemia induced by abdominal aorta ligation tightly below the renal arteries, was analyzed for phospholipid composition and levels of lipid peroxidation products after 10, 20, and 40 min of the insult. Under conditions when spinal cord blood flow was decreased below 5% of control, concentrations of inositol and ethanolamine phospholipids were decreased by 30% and 10%, respectively. Phosphatidic acid concentration was also altered during ischemia. No accumulation of thiobarbituric acid reactive substances (TBA-RS), conjugated dienes and fluorescent lipid soluble material was found throughout the ischemic period. Pattern of TBA-RS, conjugated diene, and fluorophore formation during postischemic in vitro incubation without and with a peroxidation couple (Fe²⁺, ascorbic acid) showed increased susceptibility to postischemic lipid peroxidation in tissues after 20 and 40 min of ischemia.     

The signaling lipid phosphatidylinositol‐3,5‐bisphosphate targets plant CLC‐a anion/H+ exchange activity

Phosphatidylinositol‐3,5‐bisphosphate (PI(3,5)P₂) is a low‐abundance signaling lipid associated with endo‐lysosomal and vacuolar membranes in eukaryotic cells. Recent studies on Arabidopsis indicated a critical role of PI(3,5)P₂ in vacuolar acidification and morphology during ABA‐induced stomatal closure, but the molecular targets in plant cells remained unknown. By using patch‐clamp recordings on Arabidopsis vacuoles, we show here that PI(3,5)P₂ does not affect the activity of vacuolar H⁺‐pyrophosphatase or vacuolar H⁺‐ATPase. Instead, PI(3,5)P₂ at low nanomolar concentrations inhibited an inwardly rectifying conductance, which appeared upon vacuolar acidification elicited by prolonged H⁺ pumping activity. We provide evidence that this novel conductance is mediated by chloride channel a (CLC‐a), a member of the anion/H⁺ exchanger family formerly implicated in stomatal movements in Arabidopsis. H⁺‐dependent currents were absent in clc‐a knock‐out vacuoles, and canonical CLC‐a‐dependent nitrate/H⁺ antiport was inhibited by low concentrations of PI(3,5)P₂. Finally, using the pH indicator probe BCECF, we show that CLC‐a inhibition contributes to vacuolar acidification. These data provide a mechanistic explanation for the essential role of PI(3,5)P₂ and advance our knowledge about the regulation of vacuolar ion transport.     

Amelioration of altered antioxidant status and membrane linked functions by vanadium andTrigonella in alloxan diabetic rat brains

Trigonella foenum graecum seed powder (TSP) and sodium orthovanadate (SOV) have been reported to have antidiabetic effects. However, SOV exerts hypoglycemic effects at relatively high doses with several toxic effects. We used low doses of vanadate in combination with TSP and evaluated their antidiabetic effects on antioxidant enzymes and membrane-linked functions in diabetic rat brains. In rats, diabetes was induced by alloxan monohydrate (15 mg/100 g body wt.) and they were treated with 2 IU insulin, 0.6 mg/ml SOV, 5% TSP and a combination of 0.2 mg/ml SOV with 5% TSP for 21 days. Blood glucose levels, activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), Na⁺/K⁺ ATPase, membrane lipid peroxidation and fluidity were determined in different fractions of whole brain after 21 days of treatment. Diabetic rats showed high blood glucose (P < 0.001), decreased activities of SOD, catalase and Na⁺/K⁺ ATPase (P < 0.01,P < 0.001 andP < 0.01), increased levels of GPx and MDA (P < 0.01 andP < 0.001) and decreased membrane fluidity (P < 0.01). Treatment with different antidiabetic compounds restored the above-altered parameters. Combined dose ofTrigonella and vanadate was found to be the most effective treatment in normalizing these alterations. Lower doses of vanadate could be used in combination with TSP to effectively counter diabetic alterations without any toxic effects.     

Effect of vitamin D3 on behavioural and biochemical parameters in diabetes type 1‐induced rats

Diabetes is associated with long‐term complications in the brain and reduced cognitive ability. Vitamin D₃ (VD₃) appears to be involved in the amelioration of hyperglycaemia in streptozotocin (STZ)‐induced diabetic rats. Our aim was to analyse the potential of VD₃ in avoiding brain damage through evaluation of acetylcholinesterase (AChE), Na⁺K⁺‐adenosine triphosphatase (ATPase) and delta aminolevulinate dehydratase (δ‐ALA‐D) activities and thiobarbituric acid reactive substance (TBARS) levels from cerebral cortex, as well as memory in STZ‐induced diabetic rats. Animals were divided into eight groups (n = 5): control/saline, control/metformin (Metf), control/VD₃, control/Metf + VD₃, diabetic/saline, diabetic/Metf, diabetic/VD₃ and diabetic/Metf + VD₃. Thirty days after treatment, animals were submitted to contextual fear‐conditioning and open‐field behavioural tests, after which they were sacrificed and the cerebral cortex was dissected. Our results demonstrate a significant memory deficit, an increase in AChE activity and TBARS levels and a decrease in δ‐ALA‐D and Na⁺K⁺‐ATPase activities in diabetic rats when compared with the controls. Treatment of diabetic rats with Metf and VD₃ prevented the increase in AChE activity when compared with the diabetic/saline group. In treated diabetic rats, the decrease in Na⁺K⁺‐ATPase was reverted when compared with non‐treated rats, but the increase in δ‐ALA‐D activity was not. VD₃ prevented diabetes‐induced TBARS level and improved memory. Our results show that VD₃ can avoid cognitive deficit through prevention of changes in important enzymes such as Na⁺K⁺‐ATPase and AChE in cerebral cortex in type 1 diabetic rats. Copyright © 2014 John Wiley & Sons, Ltd.     

The Decrease on Na+, K+-ATPase Activity in the Cortex, but not in Hippocampus, is Reverted by Antioxidants in an Animal Model of Sepsis

In the present study, we investigated whether sepsis induced by cecal ligation and puncture (CLP) modifies Na⁺, K⁺-ATPase activity, mRNA expression, and cerebral edema in hippocampus and cerebral cortex of rats and if antioxidant (ATX) treatment prevented the alterations induced by sepsis. Rats were subjected to CLP and were divided into three groups: sham; CLP??rats were subjected to CLP without any further treatment; and ATX?CCLP plus administration of N-acetylcysteine plus deferoxamine. Several times (6, 12, and 24) after CLP or sham operation, the rats were killed and hippocampus and cerebral cortex were isolated. Na⁺, K⁺-ATPase activity was inhibited in the hippocampus 24?h after sepsis, and ATX treatment was not able to prevent this inhibition. The Na⁺, K⁺-ATPase activity also was inhibited in cerebral cortex 6, 12, and 24?h after sepsis. No differences on Na⁺, K⁺-ATPase catalytic subunit mRNA levels were found in the hippocampus and cerebral cortex after sepsis. ATX treatment prevents Na⁺, K⁺-ATPase inhibition only in the cerebral cortex. Na⁺, K⁺-ATPase inhibition was not associated to increase brain water content. In conclusion, the present study demonstrated that sepsis induced by CLP inhibits Na⁺, K⁺-ATPase activity in a mechanism dependent on oxidative stress, but this is not associated to increase brain water content.     

Variations in myocardial CPK and Na+-K+ ATPase following normo- and hypothermic exposure to dimethyl sulfoxide and glycerol.

Exposure of canine myocardial tissue homogenates to Me₂SO glycerol (20 to 60%) for periods up to 8 hr resulted in significant alterations in enzyme activity at 0 °, 18 °, and 37 °C. Both CPK and Na⁺-K⁺ ATPase demonstrate anomalous enhancement of activity at each temperature with glycerol. Me₂SO provides a similar enhancement of Na⁺-K⁺ ATPase activity at hypothermic temperatures up to 40%. Thereafter, nearly complete inhibition resulted. Under normothermic conditions complete Me₂SO inhibition occurred at 40 °. CPK activity diminished in a linear fashion after 4 hr at 18 ° and 37 ° but was unaffected by up to 40% Me₂SO at 0 °C. The results suggest that disruption of the CPK-Na⁺-K⁺ ATPase systems may be minimized by hypothermic perfusion at low cryoprotectant concentrations.     

Early alterations induced by carbon tetrachloride in the lipids of the membranes of the endoplasmic reticulum of the liver cell II. Distribution of the alterations in the various lipid fractions

The distribution of carbon tetrachloride-induced alterations of membrane lipids in various fractions of liver microsomal lipids was studied. The chromatographic spot (referred to as the “D” spot in the previous paper [1]) which has been shown to contain the compounds responsible for the diene conjugation absorption [1], was found in the fatty acid methyl esters prepared from the fraction containing phosphatidylethanolamine (PE) and also in those obtained from the fraction containing phosphatidylserine (PS) and phosphatidylinositol (PI). The absorption of conjugated dienes was very marked in PE and less intense in PS and PI. The fatty acid methyl esters prepared from the fraction containing phosphatidylcholine (PC) showed no presence of the “D” spot and minimal absorption of conjugated dienes.A decrease in arachidonic acid content was found in the fraction containing PE, while no change in content of this fatty acid was found in the fraction containing PC. Results similar to those observed for PC were also found for neutral lipids (NL).Analysis of the fatty acid methyl esters of the various lipid fractions by gas-liquid chromatography (GLC) with an electron capture detector (ECD) gave a qualitative index of the free radical attack by CCl₄ metabolites. Quantitative estimation was attained by study of the irreversible binding of ¹⁴C from ¹⁴CCl₄ to the various lipid fractions. It was found that the fraction containing PS had the highest specific activity, while the fraction containing PC had the lowest specific activity of all the phospholipids. Thin layer chromatography (TLC) of the fraction containing PS revealed that only 11% of the radioactivity was associated with the pure PS moiety, while the remainder was associated with uncharacterized lipids (probably oxidation products).The possible relevance of the alterations induced by carbon tetrachloride in the various phospholipid fractions of liver microsomes to functional changes is discussed.     

Potassium uptake by platelets from Down's syndrome and normal subjects

Potassium uptake was studied in Down's syndrome (D.S.) platelets to determine if the Na⁺/K⁺ ATPase mediated movement of this ion was decreased compared to normal platelets. Total uptake of ⁴²K was 1.58±0.16 μmoles/hr/10⁹ normal platelets but was decreased to 1.06±0.06 μmoles/hr/10⁹ D.S. platelets (p<.001). Na⁺/K⁺ ATPase mediated (ouabain sensitive) K⁺ uptake was 0.87±0.05 μmoles/hr/10⁹ normal platelets but only 0.54±0.04 μmoles/hr/10⁹ in D.S. platelets (p<.001). As the Na⁺/K⁺ ATPase mediated outward movement of Na⁺ is decreased in D.S. platelets, the present work demonstrates that bidirectional functional imparrment of the Na⁺/K⁺ ATPase pump is present in D.S. platelets.     

Clomipramine Treatment and Repeated Restraint Stress Alter Parameters of Oxidative Stress in Brain Regions of Male Rats

This study aimed to compare the effects of repeated restraint stress alone and the combination with clomipramine treatment on parameters of oxidative stress in cerebral cortex, striatum and hippocampus of male rats. Animals were divided into control and repeated restraint stress, and subdivided into treated or not with clomipramine. After 40 days of stress and 27 days of clomipramine treatment with 30 mg/kg, the repeated restraint stress alone reduced levels of Na⁺, K⁺-ATPase in all tissues studied. The combination of repeated restraint stress and clomipramine increased the lipid peroxidation, free radicals and CAT activity as well as decreased levels of NP-SH in the tissues studied. However, Na⁺, K⁺-ATPase level decreased in striatum and cerebral cortex and the SOD activity increased in hippocampus and striatum. Results indicated that clomipramine may have deleterious effects on the central nervous system especially when associated with repeated restraint stress and chronically administered in non therapeutic levels.