A brain specific alternatively spliced isoform of nonmuscle myosin IIA lacks its mechanoenzymatic activities.

Recent genomic studies reported that 90 to 95% of human genes can undergo alternative splicing, by which multiple isoforms of proteins are synthesized. However, the functional consequences of most of the isoforms are largely unknown. Here, we report a novel alternatively spliced isoform of nonmuscle myosin IIA (NM IIA), called NM IIA2, which is generated by the inclusion of 21 amino acids near the actin-binding region (loop 2) of the head domain of heavy chains. Expression of NM IIA2 is found exclusively in the brain tissue, where it reaches a maximum level at 24 h during the circadian rhythm. The actin-dependent Mg2+-ATPase activity and in vitro motility assays reveal that NM IIA2 lacks its motor activities but localizes with actin filaments in cells. Interestingly, NM IIA2 can also make heterofilaments with NM IIA0 (noninserted isoform of NM IIA) and can retard the in vitro motility of NM IIA, when the two are mixed. Altogether, our findings provide the functional importance of a previously unknown alternatively spliced isoform, NM IIA2, and its potential physiological role in regulating NM IIA activity in the brain.

Contamination gradient affects differently carbonic anhydrase activity of mollusks depending on their feeding habits.

Aquatic organisms that inhabit coastal areas are often exposed to several contaminants. It is known that the bioaccumulation of contaminants can be amplified according to the species feeding habits and contaminant properties. As a consequence, species can experience different effects to contaminant exposure even if they inhabit the same area. The present study aimed to investigate the activities of carbonic anhydrase (CA), Ca2+-ATPase, and Mg2+-ATPase in different tissues (soft tissue, mantle, and gill) of three mollusk species (Lottia subrugosa, Stramonita brasiliensis, and Crassostrea brasiliana) with different feeding habits (herbivore, carnivore, and filter-feeder, respectively) which were sampled within a known contamination gradient at Santos Estuarine System (Southeastern Brazil). From the three enzymes tested, only CA was affected by the presence of contaminants within the contamination gradient evaluated. In general, the CA activity from the three species were lower in contaminated sites when compared to the reference site. The contrasting CA activity response observed in S. brasiliensis compared to L. subrugosa and C. brasiliana could be related to the tissue-specificity of this enzyme activity and species feeding habits (filter-feeders can accumulate more contaminants than herbivores and even carnivores). Results indicated that C. brasiliana mantle is the most suitable tissue for the use of CA analysis as a biomarker.

Na+/K+- and Mg2+-ATPases and Their Interaction with AMPA, NMDA and D2 Dopamine Receptors in an Animal Model of Febrile Seizures.

Febrile seizures (FS) are one of the most common seizure disorders in childhood which are classified into short and prolonged, depending on their duration. Short FS are usually considered as benign. However, epidemiological studies have shown an association between prolonged FS and temporal lobe epilepsy. The development of animal models of FS has been very useful to investigate the mechanisms and the consequences of FS. One of the most used, the "hair dryer model", has revealed that prolonged FS may lead to temporal lobe epilepsy by altering neuronal function. Several pieces of evidence suggest that Na+/ K+-ATPase and Mg2+-ATPase may play a role in this epileptogenic process. In this work, we found that hyperthermia-induced seizures (HIS) significantly increased the activity of Na+/ K+-ATPase and Mg2+-ATPase five and twenty days after hyperthermic insult, respectively. These effects were diminished in response to AMPA, D2 dopamine A1 and A2A receptors activation, respectively. Furthermore, HIS also significantly increased the protein level of the AMPA subunit GluR1. Altogether, the increased Na+/ K+-ATPase and Mg2+-ATPase agree well with the presence of protective mechanisms. However, the reduction in ATPase activities in the presence of NMDA and AMPA suggest an increased propensity for epileptic events in adults.

A Preparative Method for the Isolation of Calponin from Molluscan Catch Muscle.

We describe the development of a preparative method to isolate molluscan catch muscle, calponin. This method is based on the ability of calponin to interact with actin in a temperature-dependent manner. After extracting thin filaments, as previously described, the extract was ultracentrifuged at 2 °C. While other surface proteins of thin filaments co-precipitated with actin, calponin, along with some minor contaminants, remained in the supernatant. Calponin was purified through cation-exchange chromatography. The yield of pure protein was four-fold higher than that achieved through high-temperature extraction. To evaluate functionally isolated proteins, we determined the effect of calponin on Mg2+-ATPase activity of hybrid and non-hybrid actomyosin. The degree of ATPase inhibition was consistent with previously published data but strongly dependent on the environmental conditions and source of actin and myosin used. Furthermore, at low concentrations, calponin could induce the ATPase activity of hybrid actomyosin. This result was consistent with data indicating that calponin can modulate actin conformation to increase the relative content of "switched on" actin monomers in thin filaments. We assume that calponin obtained by the isolation method proposed herein is a fully functional protein that can both inhibit and induce the ATPase activity.

Melatonin Improves Reduced Activities of Membrane ATPases and Preserves Ultrastructure of Gray and White Matter in the Rat Brain Ischemia/Reperfusion Model.

Ischemia/reperfusion (I/R) is among the most frequent neurological problems and early intervention to limit the damage is crucial in decreasing mortality and morbidity. Based on reports regarding beneficial effects of melatonin, we investigated its impact on Na+-K+/Mg2+ ATPase and Ca2+/Mg2+ ATPase activities and ultrastructure of gray and white matter in the rat forebrain I/R model. Adult Wistar-albino rats (n = 78), were randomized into control, ischemia (I), ischemia/reperfusion (I/R), low (I/R + melatonin 400 µg/kg), moderate (I/R + melatonin 1200 µg/kg), and high (I/R + melatonin 2400 µg/kg) dose melatonin. Two-vessel occlusion combined with hypotension (15 min) induced ischemia and reperfusion (75 min) achieved by blood reinfusion were performed. Activities of the membrane-bound enzyme, brain malondialdehyde levels, and brain matter ultrastructure were examined in frontoparietal cortices. Melatonin lowered production of malondialdehyde in a dose-dependently. The enzyme activities attenuated under I and I/R, improved with melatonin treatment. I and I/R severely disturbed gray and white matter morphology. Melatonin, in all applied doses, decreased ultrastructural damages in both gray and white matter. Favorable effects of melatonin can be attributed to its antioxidant properties suggesting that it could be a promising neuroprotective agent against I/R injury being effective both for gray and white matter due to favorable biological properties.

Contraceptive efficacy of sperm agglutinating factor from Staphylococcus warneri, isolated from the cervix of a woman with inexplicable infertility.

BACKGROUND: Voluntary control of fertility is of paramount importance to the modern society. But since the contraceptive methods available for women have their limitations such as urinary tract infections, allergies, cervical erosion and discomfort, a desperate need exists to develop safe methods. Vaginal contraceptives may be the answer to this problem, as these are the oldest ways of fertility regulation, practiced over the centuries. With minimal systemic involvement, these are also the safest. Natural substances blocking or impairing the sperm motility offer as valuable non-cytotoxic vaginal contraceptives. Antimicrobial peptides (AMPs) isolated from plants, animals and microorganisms are known to possess sperm immobilizing and spermicidal properties. Following this, in the quest for alternative means, we have cloned, over expressed and purified the recombinant sperm agglutinating factor (SAF) from Staphylococcus warneri, isolated from the cervix of a woman with unexplained infertility. METHODS: Genomic library of Staphylococcus warneri was generated in Escherichia coli using pSMART vector and screened for sperm agglutinating factor (SAF). The insert in sperm agglutinating transformant was sequenced and was found to express ribonucleotide-diphosphate reductase-α sub unit. The ORF was sub-cloned in pET28a vector, expressed and purified. The effect of rSAF on motility, viability, morphology, Mg++-dependent ATPase activity and acrosome status of human sperms was analyzed in vitro and contraceptive efficacy was evaluated in vivo in female BALB/c mice. RESULTS: The 80 kDa rSAF showed complete sperm agglutination, inhibited its Mg2+-ATPase activity, caused premature sperm acrosomal loss in vitro and mimicked the pattern in vivo showing 100% contraception in BALB/c mice resulting in prevention of pregnancy. The FITC labeled SAF was found to bind the entire surface of spermatozoa. Vaginal application and oral administration of rSAF to mice for 14 successive days did not demonstrate any significant change in vaginal cell morphology, organ weight and tissue histology of reproductive and non-reproductive organs and had no negative impact in the dermal and penile irritation tests. CONCLUSION: The Sperm Agglutinating Factor from Staphylococcus warneri, natural microflora of human cervix, showed extensive potential to be employed as a safe vaginal contraceptive.

Relationship between the characteristics of rigor-mortis-related actomyosin and muscle fiber types in the ordinary muscle of various fishes.

BACKGROUND: Rigor mortis occurs when muscle extension vanishes through the irresistible coupling of actin and myosin by the consumption of adenosine triphosphate as energy. To clarify the cause of the differences in the progression of rigor mortis, seven fish species were used as samples. The superprecipitation reaction and Mg2+ -ATPase activity of actomyosin in dorsal ordinary muscle were measured, and the slope of the regression line between these two variables was calculated for each fish specimen. The fiber types of the dorsal ordinary muscle in each sample fish were discriminated by the stability of actomyosin ATPase at acid and alkaline preincubations. RESULT: Positive correlations were found between Mg2+ -ATPase activity and the superprecipitation reaction of actomyosin in all 27 fish specimens. The slopes of the regression lines were different not only between fish species but also in fish specimens within the same species. The area ratios of pink muscle fibers and the IIa and/or IIb subtypes of white muscle fibers in the dorsal ordinary muscle were also different between fish species, as well as in specimens within the same fish species. A positive correlation was found between the area ratios of pink muscle fibers in dorsal ordinary muscle and the slopes of the regression line. CONCLUSION: It was suggested that the differences in characteristics of rigor-mortis-related actomyosin of fish might have been caused by the differences in the interposition ratio of muscle fiber types, especially of the pink muscle fiber type, in the dorsal ordinary muscle. © 2019 Society of Chemical Industry.

From ATP to PTP and Back: A Dual Function for the Mitochondrial ATP Synthase.

Mitochondria not only play a fundamental role in heart physiology but are also key effectors of dysfunction and death. This dual role assumes a new meaning after recent advances on the nature and regulation of the permeability transition pore, an inner membrane channel whose opening requires matrix Ca(2+) and is modulated by many effectors including reactive oxygen species, matrix cyclophilin D, Pi (inorganic phosphate), and matrix pH. The recent demonstration that the F-ATP synthase can reversibly undergo a Ca(2+)-dependent transition to form a channel that mediates the permeability transition opens new perspectives to the field. These findings demand a reassessment of the modifications of F-ATP synthase that take place in the heart under pathological conditions and of their potential role in determining the transition of F-ATP synthase from and energy-conserving into an energy-dissipating device.

Changes in mitochondrial properties may contribute to enhanced resistance to ischemia-reperfusion injury in the diabetic rat heart.

Diabetes mellitus, besides having deleterious effects, induces cardiac adaptation that may reduce the heart's susceptibility to ischemia-reperfusion (IR) injury. This study aimed to investigate whether changes in mitochondrial properties are involved in the mechanisms of increased resistance of the diabetic heart to IR. Adult male Wistar rats were made diabetic by a single dose of streptozotocin (65 mg·kg-1, i.p.), and on the day 8, Langendorff-perfused hearts were subjected to 30 min global ischemia and 40 min reperfusion. Baseline preischemic parameters in the diabetic hearts did not differ markedly from those in the nondiabetic controls, except for lower left ventricular developed pressure, higher mitochondrial membrane fluidity, and protein levels of manganese superoxide dismutase. On the other hand, diabetic hearts showed significantly better post-IR functional restoration and reduced arrhythmogenesis associated with lower reactive oxygen species production as compared with healthy controls. IR decreased membrane fluidity in both experimental groups; however, it led to a complete recovery of mitochondrial Mg2+-ATPase activity in diabetics in contrast to its reduction in nondiabetics. These findings indicate that the heart may become adapted to diabetes-induced alterations that might increase its tolerance to an ischemic insult. Preserved mitochondrial function might play a role in the mechanisms of the heart's resistance to IR injury in diabetics.

Effects of Fullerene Derivatives on Activity of Ca2+-ATPase of the Sarcoplasmic Reticulum and cGMP Phosphodiesterase.

We studied the effects of new water-soluble polysubstituted fullerene C60 (PFD) derivatives on activity of Ca2+-Mg2+ ATPase of the sarcoplasmic reticulum and cGMP phosphodiesterase. All examined fullerene derivatives inhibited activity of both enzymes. For instance, PFD-I, PFD-II, PFD-III, PFD-V, PFD-IX, PFD-X, and PFD-XI in a concentration of 5×10-5 M completely inhibited hydrolytic and transport functions of Ca2+-ATPase. These compounds in a concentration of 5×10-6 suppressed active transport of calcium ions by 51±5, 77±8, 52±5, 52±5, 100±10, 80±8, and 100±10%, respectively, and inhibited ATP hydrolysis by 31±3, 78±8, 18±2, 29±3, 78±8, 63±7, and 73±9%, respectively, uncoupling the hydrolytic and transport functions of the enzyme. PFD-I noncompetitive and reversibly reduced activity of Ca2+-ATPase (Ki=2.3×10-6 M). All the studied fullerene derivatives (except for PFD-VII) inhibited cGMP phosphodiesterase by more than 80% in concentration of 10-4 M and higher and by more than 50% in concentration of 10-5 M. PFD-I is a non-competitive reversible inhibitor of cGMP phosphodiesterase (Ki=7×10-6 M). These results allow us to expect antimetastatic, antiaggregatory, antihypertensive and vasodilative activity of the studied compounds.

Ardipusilloside-I stimulates gastrointestinal motility and phosphorylation of smooth muscle myosin by myosin light chain kinase.

Ardipusilloside-I is a natural triterpenoid saponin, which was isolated from Ardisia pusilla A. DC. The aim of the study was to evaluate the stimulation of ardipusilloside-I on gastrointestinal motility in vitro and in vivo. The experiment of smooth muscle contraction directly monitored the contractions of the isolated jejunal segment (IJS) in different contractile states, and the effects of ardipusilloside-I on myosin were measured in the presence of Ca2+-calmodulin using the activities of 20 kDa myosin light chain (MLC20) phosphorylation and myosin Mg2+-ATPase. The effects of ardipusilloside-I on gastro emptying and intestinal transit in constipation-predominant rats were observed, and the MLCK expression in jejuna of constipated rats was determined by western blot. The results showed that, ardipusilloside-I increased the contractility of IJS in a dose-dependent manner and reversed the low contractile state (LCS) of IJS induced by low Ca2+, adrenaline, and atropine respectively. There were synergistic effects on contractivity of IJS between ardipusilloside-I and ACh, high Ca2+, and histamine, respectively. Ardipusilloside-I could stimulate the phosphorylation of MLC20 and Mg2+-ATPase activities of Ca2+- dependent phosphorylated myosin. Ardipusilloside-I also stimulated the gastric emptying and intestinal transit in normal and constipated rats in vivo, respectively, and increased the MLCK expression in the jejuna of constipation-predominant rats. Briefly, the findings demonstrated that ardipusilloside-I could effectively excite gastrointestinal motility in vitro and in vivo.

The effect of subchronic supplementation with folic acid and l-arginine on homocysteine-induced seizures.

The aim of the present study was to examine the effect of subchronic co-administration of folic acid (F) and l-arginine (A) on behavioural and electroencephalographic (EEG) characteristics of dl homocysteine thiolactone (H) induced seizures in adult rats. The activity of membrane ATPases in different brain regions were also investigated. Rats were treated with F, A, or vehicle for 15 days (regimen: F 5 mg/kg + A 500 mg/kg (F5A500); F 10 mg/kg + A 300 mg/kg (F10A300)). Seizures were elicited by convulsive dose of H (H, F5A500H, F10A300H) Subchronic supplementation with F and A did not affect seizure incidence, number of seizure episodes, and severity in F5A500H and F10A300H groups vs. H group. However, a tendency to increase latency and decrease the number of seizure episodes was noticed in the F10A300H group. EEG mean spectral power densities during ictal periods were significantly lower in F10A300H vs. H group. The activity of Na+/K+-ATPase and Mg2+-ATPase was significantly increased in almost all examined structures in rats treated with F and A. We can conclude that subchronic supplementation with folic acid and l-arginine has an antiepileptic effect in dl homocysteine thiolactone induced epilepsy.

Insight into mechanism of lanthanum (III) induced damage to plant photosynthesis.

A great deal of literature is available regarding the environmental and ecological effects of rare earth element pollution on plants. These studies have shown that excess lanthanum (La) (III) in the environment can inhibit plant growth and even cause plant death. Moreover, inhibition of plant photosynthesis is known to be one of the physiological bases of these damages. However, the mechanism responsible for these effects is still unclear. In this study, the mechanism of La(III)-induced damage to plant photosynthesis was clarified from the viewpoint of the chloroplast ultrastructure, the contents of chloroplast mineral elements and chlorophyll, the transcription of chloroplast ATPase subunits and chloroplast Mg(2+)-ATPase activity, in which rice was selected as a study object. Following treatment with low level of La(III), the chloroplast ultrastructure of rice was not changed, and the contents of chloroplast mineral elements (Mg, P, K, Ca, Mn, Fe, Ni, Cu, and Zn) increased, but the chlorophyll content did not change significantly. Moreover, the transcription of chloroplast ATPase subunits, chloroplast Mg(2+)-ATPase activity, the net photosynthetic rate and growth indices increased. Following treatment with high levels of La(III), the chloroplast ultrastructure was damaged, chloroplast mineral elements (except Cu and Zn) and chlorophyll contents decreased, and the transcription of chloroplast ATPase subunits, chloroplast Mg(2+)-ATPase activity, the net photosynthetic rate and growth indices decreased. Based on these results, a possible mechanism of La(III)-induced damage to plant photosynthesis was proposed to provide a reference for scientific evaluation of the potential ecological risk of rare earth elements in the environment.

Exposure to ethanol during neurodevelopment modifies crucial offspring rat brain enzyme activities in a region-specific manner.

The experimental simulation of conditions falling within "the fetal alcohol spectrum disorder" (FASD) requires the maternal exposure to ethanol (EtOH) during crucial neurodevelopmental periods; EtOH has been linked to a number of neurotoxic effects on the fetus, which are dependent upon the extent and the magnitude of the maternal exposure to EtOH and for which very little is known with regard to the exact mechanism(s) involved. The current study has examined the effects of moderate maternal exposure to EtOH (10 % v/v in the drinking water) throughout gestation, or gestation and lactation, on crucial 21-day-old offspring Wistar rat brain parameters, such as the activities of acetylcholinesterase (AChE) and two adenosine triphosphatases (Na(+),K(+)-ATPase and Mg(2+)-ATPase), in major offspring CNS regions (frontal cortex, hippocampus, hypothalamus, cerebellum and pons). The implemented experimental setting has provided a comparative view of the neurotoxic effects of maternal exposure to EtOH between gestation alone and a wider exposure timeframe that better covers the human third trimester-matching CNS neurodevelopment period (gestation and lactation), and has revealed a CNS region-specific susceptibility of the examined crucial neurochemical parameters to the EtOH exposure schemes attempted. Amongst these parameters, of particular importance is the recorded extensive stimulation of Na(+),K(+)-ATPase in the frontal cortex of the EtOH-exposed offspring that seems to be a result of the deleterious effect of EtOH during gestation. Although this stimulation could be inversely related to the observed inhibition of AChE in the same CNS region, its dependency upon the EtOH-induced modulation of other systems of neurotransmission cannot be excluded and must be further clarified in future experimental attempts aiming to simulate and to shed more light on the milder forms of the FASD-related pathophysiology.

Influence of kaempferol, a flavonoid compound, on membrane-bound ATPases in streptozotocin-induced diabetic rats.

CONTEXT: Kaempferol is a flavonoid found in many edible plants (e.g. tea, cabbage, beans, tomato, strawberries, and grapes) and in plants or botanical products commonly used in traditional medicine. Numerous preclinical studies have shown that kaempferol have a wide range of pharmacological activities, including antioxidant, anti-inflammatory, anticancer, cardioprotective, neuroprotective, and antidiabetic activities. OBJECTIVE: The present study investigates the effect of kaempferol on membrane-bound ATPases in erythrocytes and in liver, kidney, and heart of streptozotocin (STZ)-induced diabetic rats. MATERIALS AND METHODS: Diabetes was induced into adult male albino rats of the Wistar strain, by intraperitoneal administration of STZ (40 mg/kg body weight (BW)). Kaempferol (100 mg/kg BW) or glibenclamide (600 µg/kg BW) was administered orally once daily for 45 d to normal and STZ-induced diabetic rats. The effects of kaempferol on membrane-bound ATPases (total ATPase, Na(+)/K(+)-ATPase, Ca(2+)-ATPase, and Mg(2+)-ATPase) activity in erythrocytes and in liver, kidney, and heart were determined. RESULTS: In our study, diabetic rats had significantly (p < 0.05) decreased activities of total ATPases, Na(+)/K(+)-ATPase, Ca(2+)-ATPase, and Mg(2+)-ATPase in erythrocytes and tissues. Oral administration of kaempferol (100 mg/kg BW) or glibenclamide (600 µg/kg BW) for a period of 45 d resulted in significant (p < 0.05) reversal of these enzymes' activities to near normal in erythrocytes and tissues when compared with diabetic control rats. DISCUSSION AND CONCLUSION: Thus, obtained results indicate that administration of kaempferol has the potential to restore deranged activity of membrane-bound ATPases in STZ-induced diabetic rats. Further detailed investigation is necessary to discover kaempferol's action mechanism.

Maternal Caffeine Consumption during Gestation and Lactation Abolishes Cortical Oxidative Stress and Restores Na+/K+-ATPase Activity in Neonates Exposed to Hyperthermia-Induced Seizures.

Caffeine is a psychoactive substance that is widely consumed by individuals of various demographics, including pregnant women. It can readily cross the blood-brain and placental barriers, easily reaching the fetal brain. In addition, caffeine has also shown antioxidant properties, as its consumption reduces oxidative stress in various pathologies, including epilepsy. Febrile seizures (FS) are among the most common convulsive disorders in infants and young children. Here, we used an animal model of FS to learn whether maternal caffeine (1 g/L) intake consumption during gestation and lactation could exert beneficial effects on the rat cortex. Neonatal development was analyzed by measuring pinna opening, eye opening, righting reflex on the surface, and geotaxis reflex. Five and twenty days after HIS, the rats were euthanized, and plasma membranes and cytosolic fractions were isolated from their cortex brain. The enzymatic activities of glutathione reductase, glutathione S-transferase, Na+/K+-ATPase, and Mg2+-ATPase, as well as the levels of thiobarbituric acid reacting substances, were quantified. Results showed that maternal caffeine intake eliminates oxidative stress and normalizes Na+/K+-ATPase activity disrupted by HIS and also affects some parameters relating to the neurodevelopment of neonates. As FS in infants has been related to epilepsy in adults, the antioxidant properties of caffeine could prevent potential damage from hyperthermia.

Efficacy on rabbits with arrhythmia: needling acupoint of Neiguan (PC6) at shallow or deep depth, and retaining needles for 10, 20, or 30 min.

OBJECTIVE: To compare the effects of Neiguan (PC6) acupuncture at different depths and retention time on arrhythmia duration, myocardial tissue morphology, mRNA expression level of L-type calcium channel α1C subunit and Ca2 + -Mg2 + -AtPase activity in tachirrhythmia model of rabbits. METHODS: The tachyarrhythmia model was made by intravenous injection of barium chloride into the ears of rabbits. A total of 56 healthy adult male New Zealand big-eared white rabbits, apply the random number table method, divided into normal control group (group A), model group (group B), shallow needling Neiguan (PC6) 10 min group (group C), shallow needling Neiguan (PC6) 20 min group (group D), shallow needling Neiguan (PC6) 30 min group (group E), deep needling Neiguan (PC6) 10 min group (group F), deep needling Neiguan (PC6) 20 min group (group G), deep needling Neiguan (PC6) 30 min group (group H), 7 animals in each group. Electrocardiograms were used to collect the duration of arrhythmia; hematoxylin-eosin staining method was performed on myocardial tissue, RT-PCR tested the expression of α1C subunit mRNA, and the activity of Ca2 + -Mg2 + -ATPase were quantified by phosphorus determination method. RESULTS: The duration of arrhythmia in each acupuncture treatment group was shortened to varying degrees. Compare to the model group, the tissue damage from barium chloride inducing was improved in the acupuncture group. Compared to the model group, except for group E, most treatment groups had varying degrees of improvement with significantly down-regulated L-type calcium channel α1C subunit mRNA expressions level and increased Ca2+ -Mg2+ -ATPase activity. CONCLUSIONS: The effect of acupuncture at Neiguan (PC6) with different depths and retention time can reduce the duration of arrhythmia induced by barium chloride relatively, improve the induced pathological changes, down regulate L-type calcium channel α1C subunit mRNA expressions level and increase Ca2 + -Mg2 + -ATPase activity. Both the shallow and deep tissues of Neiguan (PC6) may be involved in transmitting acupuncture information. There is an optimal induction period for shallow needling at Neiguan (PC6) to reach the best therapeutic effect.

Effects of salt and waterlogging stresses and their combination on leaf photosynthesis, chloroplast ATP synthesis, and antioxidant capacity in wheat.

The objective of this study was to investigate the effects of salt (ST) and waterlogging (WL) stresses and their combination (SW) on leaf photosynthesis, chloroplast ATP synthesis, and antioxidant capacity in wheat (Triticum aestivum L.). Two winter wheat cultivars, Huaimai 17 and Yangmai 12, differing in their tolerance to ST and WL stresses were used. The plants were grown in pots and were subjected to ST, WL, and SW from 7 days after anthesis (DAA). The WL and SW treatments lasted for 5 days, while the ST treatment was continuously imposed during the grain filling stage. Significant decrease in net photosynthetic rate (PN) of the flag leaf was observed under the ST and SW treatments from 10 DAA in Yangmai 12 and at 18 DAA in both cultivars, which could be stomatal closure related. At 18 DAA, clear reduction in PN under the ST and SW treatments was observed, which was associated with chlorosis, damages to the photosystem II (PSII), enhanced lipid peroxidation, and depressed ATP synthesis in the chloroplasts of the flag leaf. Whereas, WL treatment alone had slightly negative effect on PN, which was mainly attributed to leaf chlorosis and waste in harvested energy by the PSII reaction center dispersed via non-photochemical approaches.

Effect of untreated pharmaceutical plant effluent on cardiac Na+-K+- ATPase and Ca2+-Mg2+-ATPase activities in mice (Mus Musculus).

Cardiovascular diseases are major causes of non-communicable diseases (NCDs)-related throughout the world. Water pollution has been linked with the high global NCD burden but no report exists on the cardiotoxicity of untreated or poorly treated pharmaceutical effluent, despite its indiscriminate discharge into the aquatic environment in Nigeria, as in many other locations of the world. Thus, this study investigated the cardiotoxic effect of oral exposure to pharmaceutical effluent in mice. Thirty (30) male mice (Mus musculus) were randomly divided into 6 groups. Group A (control) received 0.2 ml distilled water, while groups B-F were treated with 0.2 ml 2.5%, 5.0%, 10.0%, 20.0% and 40% concentrations (v/v, effluent/distilled water) of the effluent respectively, for 28 days. Significant reductions (p<0.05) in heart weight and cardiac weight index were observed in the groups treated with 5%, 10%, 20% and 40% concentrations of the effluent, without significant change in body weight. Similarly, 28 day administration of the effluent showed significant decrease in cardiac Na+-K+-ATPase activity (p<0.05) at concentrations 10% and above, in a concentration dependent manner. However, there was insignificant decrease in cardiac Ca2+-Mg2+-ATPase activity of the exposed mice, when compared with the control group. This study provides novel information on the cardiotoxic effects of oral exposure to untreated pharmaceutical effluent, showing reduced Na+-K+-ATPase activity and decreseased myocardial atrophy. Therefore, drinking water contaminated with pharmaceutical effluent may promote the incidence of cardiovascular diseases. Further studies on the exact mechanistic routes of the induced cardiotoxicity are recommended.

Characterization of myofibrillar adenosine triphosphatase activity and liberation of actin from myofibrils upon heating chicken breast meat.

Denaturation of actin and myosin in myofibrils induced by heating at 50°C was investigated to reveal the mechanism of irreversible liberation of actin from myofibrils on heating at lower temperatures than conventional cooking. Denaturation of these proteins was determined by Mg2+ -ATPase (adenosine triphosphatase) and Ca2+ -ATPase activities. When minced meat was heated for 20 min, actin was liberated accompanying denaturation of 80% of actin and 50% of myosin. Heating of the myofibrillar fraction (MFF) isolated from meat homogenate induced much slower denaturation of actin than myosin. When MFF was heated with sarcoplasmic fractions, denaturation of actin was facilitated, suggesting that sarcoplasmic fractions contain factors to facilitate actin denaturation. Inosine-5'-monophosphate, a component of sarcoplasmic fractions, was shown to have no effect on actin and myosin denaturation. These results suggest that heating meat at 50°C dissociates binding ('Bond A') between actin and myosin participating in ATPase activities, resulting in denaturation of both proteins under influence of sarcoplasmic components. Although denaturation of actin and myosin disrupted Bond A, actin was not liberated simultaneously, suggesting the presence of another bond ('Bond B', more heat-stable than Bond A) between both proteins and necessity of disruption of Bond B for actin release from myofibrils.