scholarly journals Ca2+-ATPase activity and Ca2+ uptake by sarcoplasmic reticulum in fish heart: effects of thermal acclimation.

1998 ◽  
Vol 201 (4) ◽  
pp. 525-532 ◽  
Author(s):  
E Aho ◽  
M Vornanen
Keyword(s):  
Atpase Activity ◽  
Uptake Rate ◽  
Teleost Fish ◽  
Crucian Carp ◽  
Thermal Acclimation ◽  
The Body ◽  
Newborn Rat ◽  
Fish Heart ◽  
Adult Rat ◽  
Uptake Velocity

This study was designed to compare the activities of sarcoplasmic (SR) Ca2+-ATPase and Ca2+ uptake in fish and mammalian hearts and to determine whether thermal acclimation has any effect on the function of the cardiac SR in fish. To this end, we measured thapsigargin-sensitive Ca2+-ATPase activity and thapsigargin-inhibitable Ca2+ uptake velocity in crude cardiac homogenates of newborn and adult rats and of two teleost fish (crucian carp and rainbow trout) acclimated to low (4 degrees C) and high (17 degrees C and 24 degrees C for trout and carp, respectively) ambient temperatures. The TG-sensitive Ca2+-ATPase activity was highest in adult rat, and the corresponding activities of cold-acclimated trout, warm-acclimated trout, warm-acclimated carp, cold-acclimated carp and newborn rat were 76, 58, 43, 28 and 23 %, respectively, of that of the adult rat at 25 degrees C. SR Ca2+ uptake velocity, measured using Fura-2 at room temperature (approximately 22 degrees C), was highest in cold-acclimated trout, and the values for adult rat, warm-acclimated trout, newborn rat, warm-acclimated carp and cold-acclimated carp were 93, 56, 24, 21 and 14 % of the uptake velocity of cold-acclimated trout, respectively. When corrected to the body temperature of the animal, the relative rates of SR Ca2+ uptake were 100, 26, 19, 18, 11 and 2 % for adult rat, newborn rat, cold-acclimated trout, warm-acclimated trout, warm-acclimated carp and cold-acclimated carp, respectively. These findings show that SR Ca2+ uptake is slower in fish than in mammalian hearts and that marked species-specific differences exist among teleost fish in this respect. Furthermore, acclimation to cold increases the Ca2+ uptake rate of trout cardiac SR (complete thermal compensation) but decreases the SR Ca2+ uptake rate of crucian carp heart. This difference in acclimation response probably reflects the different activity patterns of the two species in their natural habitat during the cold season.

scholarly journals Mechanisms of L-Triiodothyronine-Induced Inhibition of Synaptosomal Na+-K+-ATPase Activity in Young Adult Rat Brain Cerebral Cortex

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Pradip K. Sarkar ◽  
Avijit Biswas ◽  
Arun K. Ray ◽  
Joseph V. Martin
Keyword(s):  
Cerebral Cortex ◽  
Atpase Activity ◽  
Adrenergic Receptor ◽  
Receptor Activation ◽  
Mammalian Brain ◽  
Neuronal Membrane ◽  
Dependent Manner ◽  
Adrenergic Agonist ◽  
Adult Rat ◽  
Dose Dependent

The role of thyroid hormones (TH) in the normal functioning of adult mammalian brain is unclear. Our studies have identified synaptosomal Na+-K+-ATPase as a TH-responsive physiological parameter in adult rat cerebral cortex. L-triiodothyronine (T3) and L-thyroxine (T4) both inhibited Na+-K+-ATPase activity (but not Mg2+-ATPase activity) in similar dose-dependent fashions, while other metabolites of TH were less effective. Although both T3and theβ-adrenergic agonist isoproterenol inhibited Na+-K+-ATPase activity in cerebrocortical synaptosomes in similar ways, theβ-adrenergic receptor blocker propranolol did not counteract the effect of T3. Instead, propranolol further inhibited Na+-K+-ATPase activity in a dose-dependent manner, suggesting that the effect of T3on synaptosomal Na+-K+-ATPase activity was independent ofβ-adrenergic receptor activation. The effect of T3on synaptosomal Na+-K+-ATPase activity was inhibited by theα2-adrenergic agonist clonidine and by glutamate. Notably, both clonidine and glutamate activateGi-proteins of the membrane second messenger system, suggesting a potential mechanism for the inhibition of the effects of TH. In this paper, we provide support for a nongenomic mechanism of action of TH in a neuronal membrane-related energy-linked process for signal transduction in the adult condition.

Anion-dependent Mg2+ influx and a role for a vacuolar H+-ATPase in sheep ruminal epithelial cells

2003 ◽  
Vol 285 (1) ◽  
pp. G45-G53 ◽  
Author(s):  
Monika Schweigel ◽  
Holger Martens
Keyword(s):  
Epithelial Cells ◽  
Atpase Activity ◽  
Primary Culture ◽  
Intracellular Ph ◽  
Uptake Rate ◽  
Ruminal Fermentation ◽  
Fermentation Products ◽  
Fluorescence Techniques ◽  
Transport Inhibitors ◽  
Stimulation Of

The K+-insensitive component of Mg2+ influx in primary culture of ruminal epithelial cells (REC) was examined by means of fluorescence techniques. The effects of extracellular anions, ruminal fermentation products, and transport inhibitors on the intracellular free Mg2+ concentration ([Mg2+]i), Mg2+ uptake, and intracellular pH were determined. Under control conditions (HEPES-buffered high-NaCl medium), the [Mg2+]i of REC increased from 0.56 ± 0.14 to 0.76 ± 0.06 mM, corresponding to a Mg2+ uptake rate of 15 μM/min. Exposure to butyrate did not affect Mg2+ uptake, but it was stimulated (by 84 ± 19%) in the presence of [Formula: see text]. In contrast, Mg2+ uptake was strongly diminished if REC were suspended in [Formula: see text]-buffered high-KCl medium (22.3 ± 4 μM/min) rather than in HEPES-buffered KCl medium (37.5 ± 6 μM/min). After switching from high- to low-Cl– solution, [Mg2+]i was reduced from 0.64 ± 0.09 to 0.32 ± 0.16 mM and the [Formula: see text]-stimulated Mg2+ uptake was completely inhibited. Bumetanide and furosemide blocked the rate of Mg2+ uptake by 64 and 40%, respectively. Specific blockers of vacuolar H+-ATPase reduced the [Mg2+]i (36%) and Mg2+ influx (38%) into REC. We interpret this data to mean that the K+-insensitive Mg2+ influx into REC is mediated by a cotransport of Mg2+ and Cl– and is energized by an H+-ATPase. The stimulation of Mg2+ transport by ruminal fermentation products may result from a modulation of the H+-ATPase activity.

scholarly journals Особливості масометричних показників та морфологічних змін головного мозку статевозрілих щурів в умовах впливу на організм сульфатів міді, цинку та заліза

2015 ◽  
Author(s):  
А. М. Романюк ◽  
Г. Ю Будко
Keyword(s):  
Copper Sulfate ◽  
Morphological Changes ◽  
The Body ◽  
Male Rats ◽  
Relative Mass ◽  
Adult Rat ◽  
Applied Anatomy ◽  
Adult Rat Brain ◽  
Long Acting ◽  
The Brain

ОСОБЛИВОСТІ МАСОМЕТРИЧНИХ ПОКАЗНИКІВ ТА МОРФОЛОГІЧНИХ ЗМІН ГОЛОВНОГО МОЗКУ СТАТЕВОЗРІЛИХ ЩУРІВ В УМОВАХ ВПЛИВУ НА ОРГАНІЗМ СУЛЬФАТІВ МІДІ, ЦИНКУ ТА ЗАЛІЗА - З метою вивчення масометричних показників щурів та їх головного мозку за умов довготривалої дії (упродовж 90 діб) на організм сульфатів міді, цинку та заліза було проведено експеримент на 48 білих статевозрілих щурах-самцях масою 200-250 г віком 5-7 місяців. Застосовували анатомічні, статистичні та загальноприйняті методики мікроанатомічного методу дослідження. Встановлено, що комбінований вплив на організм сульфатів міді цинку та заліза чинить на головний мозок досить виражений токсичний ефект, що негативно позначається на масометричних показниках загальної маси щурів та маси головного мозку. Це свідчить про розвиток у головному мозку явищ гострого набряку з ознаками геморагічної інфільтрації. Ступінь вираження набряку зростає та досягає максимальних показників наприкінці експерименту.<br />ОСОБЕННОСТИ МАСОМЕТРИЧЕСКИХ ПОКАЗАТЕЛЕЙ И МОРФОЛОГИЧЕСКИХ ИЗМЕНЕНИЙ ГОЛОВНОГО МОЗГА ПОЛОВОЗРЕЛЫХ КРЫС В УСЛОВИЯХ ВОЗДЕЙСТВИЯ НА ОРГАНИЗМ СУЛЬФАТОВ МЕДИ, ЦИНКА И ЖЕЛЕЗА - С целью изучения масометрических показателей крыс и их головного мозга в условиях длительного действия (в течение 90 суток) на организм сульфатов меди, цинка и железа был проведен эксперимент на 48 белых половозрелых крысах-самцах массой 200250 г в возрасте 5-7 месяцев. Применялись анатомические, статистические и общепринятые методики микроанатомического метода исследования. Установлено, что комбинированное воздействие на организм сульфатов меди и цинка и железа оказывает на мозг достаточно выразительный токсический эффект, что отрицательно сказывается на массометрических показателях общего веса крыс и веса головного мозга. Это свидетельствует о развитии в головном мозге явлений острого отека с признаками геморрагической инфильтрации, степень выраженности которого максимальна в конце эксперимента.<br />FEATURES OF MASS INDICES AND MORPHOLOGICAL CHANGES IN ADULT RAT BRAIN UNDER THE INFLUENCE ON THE BODY OF COPPER SULFATE, ZINC AND IRON - To study the performance of rats and their mass brain in long acting (for 90 days) on the body of copper sulfate, zinc and iron, an experiment was conducted on 48 white adult male rats weighing 200-250 gram, aged 5-7 months. There was applied anatomy, statistics and conventional techniques microanatomical research method. It was established that the combined effect on the body of copper and zinc sulphates and iron in the brain has enough expressive toxicity, which affects performance on the total weight of the rats and brain weight. This testifies to the development of brain edema, acute phenomena with signs of hemorrhagic infiltration. The severity of edema increases and reaches maximum performance at the end of the experiment.<br />Ключові слова: головний мозок, солі важких металів, відносна маса, коефіцієнт цефалізації.<br />Ключевые слова: головной мозг, соли тяжелых металлов, относительная масса, коэффициент цефа- лизации.<br />Key words: brain, salts of heavy metals, relative mass, ratio cephalization.

Nifedipine-activated Ca2+ permeability in newborn rat cortical collecting duct cells in primary culture

2001 ◽  
Vol 280 (5) ◽  
pp. C1193-C1203 ◽  
Author(s):  
Laura Valencia ◽  
Michel Bidet ◽  
Sonia Martial ◽  
Elsa Sanchez ◽  
Estela Melendez ◽  
...  
Keyword(s):  
Primary Culture ◽  
Transient Receptor Potential ◽  
Collecting Duct ◽  
Primary Cultures ◽  
Receptor Potential ◽  
Cortical Collecting Duct ◽  
Newborn Rat ◽  
Adult Rat ◽  
Intracellular Ca ◽  
Transient Receptor

To characterize Ca2+ transport in newborn rat cortical collecting duct (CCD) cells, we used nifedipine, which in adult rat distal tubules inhibits the intracellular Ca2+concentration ([Ca2+]i) increase in response to hormonal activation. We found that the dihydropyridine (DHP) nifedipine (20 μM) produced an increase in [Ca2+]i from 87.6 ± 3.3 nM to 389.9 ± 29.0 nM in 65% of the cells. Similar effects of other DHP (BAY K 8644, isradipine) were also observed. Conversely, DHPs did not induce any increase in [Ca2+]i in cells obtained from proximal convoluted tubule. In CCD cells, neither verapamil nor diltiazem induced any rise in [Ca2+]i. Experiments in the presence of EGTA showed that external Ca2+ was required for the nifedipine effect, while lanthanum (20 μM), gadolinium (100 μM), and diltiazem (20 μM) inhibited the effect. Experiments done in the presence of valinomycin resulted in the same nifedipine effect, showing that K+ channels were not involved in the nifedipine-induced [Ca2+]i rise. H2O2also triggered [Ca2+]i rise. However, nifedipine-induced [Ca2+]i increase was not affected by protamine. In conclusion, the present results indicate that 1) primary cultures of cells from terminal nephron of newborn rats are a useful tool for investigating Ca2+transport mechanisms during growth, and 2) newborn rat CCD cells in primary culture exhibit a new apical nifedipine-activated Ca2+ channel of capacitive type (either transient receptor potential or leak channel).

scholarly journals The effect of temperature and thermal acclimation on the sustainable performance of swimming scup

2007 ◽  
Vol 362 (1487) ◽  
pp. 1995-2016 ◽  
Author(s):  
Lawrence C Rome
Keyword(s):  
Steady State ◽  
Relaxation Rate ◽  
Power Output ◽  
Muscle Power ◽  
Thermal Acclimation ◽  
The Body ◽  
Effect Of Temperature ◽  
Cold Temperatures ◽  
Duty Cycles ◽  
Red Muscle

There is a significant reduction in overall maximum power output of muscle at low temperatures due to reduced steady-state (i.e. maximum activation) power-generating capabilities of muscle. However, during cyclical locomotion, a further reduction in power is due to the interplay between non-steady-state contractile properties of muscle (i.e. rates of activation and relaxation) and the stimulation and the length-change pattern muscle undergoes in vivo . In particular, even though the relaxation rate of scup red muscle is slowed greatly at cold temperatures (10°C), warm-acclimated scup swim with the same stimulus duty cycles at cold as they do at warm temperature, not affording slow-relaxing muscle any additional time to relax. Hence, at 10°C, red muscle generates extremely low or negative work in most parts of the body, at all but the slowest swimming speeds. Do scup shorten their stimulation duration and increase muscle relaxation rate during cold acclimation? At 10°C, electromyography (EMG) duty cycles were 18% shorter in cold-acclimated scup than in warm-acclimated scup. But contrary to the expectations, the red muscle did not have a faster relaxation rate, rather, cold-acclimated muscle had an approximately 50% faster activation rate. By driving cold- and warm-acclimated muscle through cold- and warm-acclimated conditions, we found a very large increase in red muscle power during swimming at 10°C. As expected, reducing stimulation duration markedly increased power output. However, the increased rate of activation alone produced an even greater effect. Hence, to fully understand thermal acclimation, it is necessary to examine the whole system under realistic physiological conditions.

In Vitro Effect of Lead on Na+, K+-ATPase Activity in Different Regions of Adult Rat Brain

2003 ◽  
Vol 26 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Prabhakara Rao Yallapragada ◽  
Jennifer Butler ◽  
Bokara Kiran Kumar ◽  
Bettaiya Rajanna
Keyword(s):  
Atpase Activity ◽  
Rat Brain ◽  
Adult Rat ◽  
Adult Rat Brain ◽  
Vitro Effect

A Quick Assay for Na+-K+-ATPase Specific Activity

2002 ◽  
Vol 57 (5-6) ◽  
pp. 562-564 ◽  
Author(s):  
Pradip K. Sarkar
Keyword(s):  
Atpase Activity ◽  
Protein Content ◽  
Simultaneous Determination ◽  
Lipid Content ◽  
Present Method ◽  
Inorganic Phosphate ◽  
Specific Activity ◽  
Adult Rat ◽  
High Lipid

The method describes a simultaneous determination of inorganic phosphate (Pi) and protein content from a reaction mixture used for assay of adult rat cerebrocortical synaptosomal membrane Na+-K+-ATPase specific activity. The present method is more convenient, accurate and quicker compared to the existing methods for the determination of Na+-K+-ATPase activity. It also eliminates the possible errors in protein estimation by other classical methods in brain, which have a high lipid content.

scholarly journals Changes in Ca-ATPase Activity and Ca Uptake Rate of Erythrocytes of the Stroke-Prone SHR in Relation to Aging

1979 ◽  
Vol 20 (5) ◽  
pp. 748-748
Author(s):  
Hideaki Higashino ◽  
Takao Yanagawa ◽  
Noriyoshi Kazimoto ◽  
Aritomo Suzuki
Keyword(s):  
Atpase Activity ◽  
Uptake Rate ◽  
Ca Uptake
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