A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.
An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.
A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.
An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
Cyclopentanophenanthrenes with a 5- or 6-membered lactone ring attached at the 17-position and SUGARS attached at the 3-position. Plants they come from have long been used in congestive heart failure. They increase the force of cardiac contraction without significantly affecting other parameters, but are very toxic at larger doses. Their mechanism of action usually involves inhibition of the NA(+)-K(+)-EXCHANGING ATPASE and they are often used in cell biological studies for that purpose.
The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.
A cardiotonic glycoside obtained mainly from Digitalis lanata; it consists of three sugars and the aglycone DIGOXIGENIN. Digoxin has positive inotropic and negative chronotropic activity. It is used to control ventricular rate in ATRIAL FIBRILLATION and in the management of congestive heart failure with atrial fibrillation. Its use in congestive heart failure and sinus rhythm is less certain. The margin between toxic and therapeutic doses is small. (From Martindale, The Extra Pharmacopoeia, 30th ed, p666)
An element that is an alkali metal. It has an atomic symbol Rb, atomic number 37, and atomic weight 85.47. It is used as a chemical reagent and in the manufacture of photoelectric cells.
A cardiac glycoside sometimes used in place of DIGOXIN. It has a longer half-life than digoxin; toxic effects, which are similar to those of digoxin, are longer lasting. (From Martindale, The Extra Pharmacopoeia, 30th ed, p665)
Unstable isotopes of rubidium that decay or disintegrate emitting radiation. Rb atoms with atomic weights 79-84, and 86-95 are radioactive rubidium isotopes.
Stable sodium atoms that have the same atomic number as the element sodium, but differ in atomic weight. Na-23 is a stable sodium isotope.
A number of different cardioactive glycosides obtained from Strophanthus species. OUABAIN is from S. gratus and CYMARINE from S. kombe. They are used like the digitalis glycosides.
Agents that have a strengthening effect on the heart or that can increase cardiac output. They may be CARDIAC GLYCOSIDES; SYMPATHOMIMETICS; or other drugs. They are used after MYOCARDIAL INFARCT; CARDIAC SURGICAL PROCEDURES; in SHOCK; or in congestive heart failure (HEART FAILURE).
Glycosides from plants of the genus DIGITALIS. Some of these are useful as cardiotonic and anti-arrhythmia agents. Included also are semi-synthetic derivatives of the naturally occurring glycosides. The term has sometimes been used more broadly to include all CARDIAC GLYCOSIDES, but here is restricted to those related to Digitalis.
A type of glycoside widely distributed in plants. Each consists of a sapogenin as the aglycone moiety, and a sugar. The sapogenin may be a steroid or a triterpene and the sugar may be glucose, galactose, a pentose, or a methylpentose.
Cyclopentanophenanthrenes with a 6-membered lactone ring attached at the 17-position and SUGARS attached at the 3-position. They are found in BUFONIDAE and often possess cardiotonic properties.
A compound that inhibits symport of sodium, potassium, and chloride primarily in the ascending limb of Henle, but also in the proximal and distal tubules. This pharmacological action results in excretion of these ions, increased urinary output, and reduction in extracellular fluid. This compound has been classified as a loop or high ceiling diuretic.
An element in the alkali metals family. It has the atomic symbol Li, atomic number 3, and atomic weight [6.938; 6.997]. Salts of lithium are used in treating BIPOLAR DISORDER.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
The aglycone constituents of CARDIAC GLYCOSIDES. The ring structure is basically a cyclopentanoperhydrophenanthrene nucleus attached to a lactone ring at the C-17 position.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
Stable potassium atoms that have the same atomic number as the element potassium, but differ in atomic weight. K-41 is a stable potassium isotope.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
A pyrazine compound inhibiting SODIUM reabsorption through SODIUM CHANNELS in renal EPITHELIAL CELLS. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with DIURETICS to spare POTASSIUM loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
An alpha-2 selective adrenergic agonist used as an antihypertensive agent.
A sulfamyl diuretic.
A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.
A benzoic-sulfonamide-furan. It is a diuretic with fast onset and short duration that is used for EDEMA and chronic RENAL INSUFFICIENCY.
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.

PST 2238: A new antihypertensive compound that modulates Na,K-ATPase in genetic hypertension. (1/3013)

A genetic alteration in the adducin genes is associated with hypertension and up-regulation of the expression of renal Na, K-ATPase in Milan-hypertensive (MHS) rats, in which increased ouabain-like factor (OLF) levels are also observed. PST 2238, a new antihypertensive compound that antagonizes the pressor effect of ouabain in vivo and normalizes ouabain-dependent up-regulation of the renal Na-K pump, was evaluated for its ability to lower blood pressure and regulate renal Na,K-ATPase activity in MHS genetic hypertension. In this study, we show that PST 2238, given orally at very low doses (1 and 10 microg/kg for 5-6 weeks), reduced the development of hypertension in MHS rats and normalized the increased renal Na,K-ATPase activity and mRNA levels, whereas it did not affect either blood pressure or Na,K-ATPase in Milan-normotensive (MNS) rats. In addition, a similar antihypertensive effect was observed in adult MHS rats after a short-term treatment. In cultured rat renal cells with increased Na-K pump activity at Vmax due to overexpression of the hypertensive variant of adducin, 5 days of incubation with PST 2238 (10(-10-)-10(-9) M) lowered the pump rate to the level of normal wild-type cells, which in turn were not affected by the drug. In conclusion, PST 2238 is a very potent compound that in MHS rats reduces blood pressure and normalizes Na-K pump alterations caused by a genetic alteration of the cytoskeletal adducin. Because adducin gene mutations have been associated with human essential hypertension, it is suggested that PST 2238 may display greater antihypertensive activity in those patients carrying such a genetic alteration.  (+info)

Fluid secretion by the malpighian tubules of the tsetse fly Glossina morsitans: the effects of ouabain, ethacrynic acid and amiloride. (2/3013)

The effects of three inhibitors of sodium transport on the secretion of fluid by the Malpighian tubules of Glossina morsitans have been observed. The cardiac glycoside, ouabain, affects neither the rate of secretion nor the sodium concentration of the fluid secreted when isolated tubules are bathed by solutions containing a range of sodium and potassium concentrations. Secretion is inhibited, however, by ethacrynic acid and amiloride. The results confirm that fluid secretion by the Malpighian tubules of this insect is dependent on the active transport of sodium ions and show that Na+/k+ exchange pumps are not involved in this process.  (+info)

Alterations of heart function and Na+-K+-ATPase activity by etomoxir in diabetic rats. (3/3013)

To examine the role of changes in myocardial metabolism in cardiac dysfunction in diabetes mellitus, rats were injected with streptozotocin (65 mg/kg body wt) to induce diabetes and were treated 2 wk later with the carnitine palmitoyltransferase inhibitor (carnitine palmitoyltransferase I) etomoxir (8 mg/kg body wt) for 4 wk. Untreated diabetic rats exhibited a reduction in heart rate, left ventricular systolic pressure, and positive and negative rate of pressure development and an increase in end-diastolic pressure. The sarcolemmal Na+-K+-ATPase activity was depressed and was associated with a decrease in maximal density of binding sites (Bmax) value for high-affinity sites for [3H]ouabain, whereas Bmax for low-affinity sites was unaffected. Treatment of diabetic animals with etomoxir partially reversed the depressed cardiac function with the exception of heart rate. The high serum triglyceride and free fatty acid levels were reduced, whereas the levels of glucose, insulin, and 3,3',-5-triiodo-L-thyronine were not affected by etomoxir in diabetic animals. The activity of Na+-K+-ATPase expressed per gram heart weight, but not per milligram sarcolemmal protein, was increased by etomoxir in diabetic animals. Furthermore, Bmax (per g heart wt) for both low-affinity and high-affinity binding sites in control and diabetic animals was increased by etomoxir treatment. Etomoxir treatment also increased the depressed left ventricular weight of diabetic rats and appeared to increase the density of the sarcolemma and transverse tubular system to normalize Na+-K+-ATPase activity. Therefore, a shift in myocardial substrate utilization may represent an important signal for improving the depressed cardiac function and Na+-K+-ATPase activity in diabetic rat hearts with impaired glucose utilization.  (+info)

A chimeric gastric H+,K+-ATPase inhibitable with both ouabain and SCH 28080. (4/3013)

2-Methyl-8-(phenylmethoxy)imidazo(1,2-a)pyridine-3acetonitrile+ ++ (SCH 28080) is a K+ site inhibitor specific for gastric H+,K+-ATPase and seems to be a counterpart of ouabain for Na+,K+-ATPase from the viewpoint of reaction pattern (i.e. reversible binding, K+ antagonism, and binding on the extracellular side). In this study, we constructed several chimeric molecules between H+,K+-ATPase and Na+,K+-ATPase alpha-subunits by using rabbit H+,K+-ATPase as a parental molecule. We found that the entire extracellular loop 1 segment between the first and second transmembrane segments (M1 and M2) and the luminal half of the M1 transmembrane segment of H+, K+-ATPase alpha-subunit were exchangeable with those of Na+, K+-ATPase, respectively, preserving H+,K+-ATPase activity, and that these segments are not essential for SCH 28080 binding. We found that several amino acid residues, including Glu-822, Thr-825, and Pro-829 in the M6 segment of H+,K+-ATPase alpha-subunit are involved in determining the affinity for this inhibitor. Furthermore, we found that a chimeric H+,K+-ATPase acquired ouabain sensitivity and maintained SCH 28080 sensitivity when the loop 1 segment and Cys-815 in the loop 3 segment of the H+,K+-ATPase alpha-subunit were simultaneously replaced by the corresponding segment and amino acid residue (Thr) of Na+,K+-ATPase, respectively, indicating that the binding sites of ouabain and SCH 28080 are separate. In this H+, K+-ATPase chimera, 12 amino acid residues in M1, M4, and loop 1-4 that have been suggested to be involved in ouabain binding of Na+, K+-ATPase alpha-subunit are present; however, the low ouabain sensitivity indicates the possibility that the sensitivity may be increased by additional amino acid substitutions, which shift the overall structural integrity of this chimeric H+,K+-ATPase toward that of Na+,K+-ATPase.  (+info)

Multiple mechanisms confer drug resistance to mitoxantrone in the human 8226 myeloma cell line. (5/3013)

Selection for in vitro drug resistance can result in a complex phenotype with more than one mechanism of resistance emerging concurrently or sequentially. We examined emerging mechanisms of drug resistance during selection with mitoxantrone in the human myeloma cell line 8226. A novel transport mechanism appeared early in the selection process that was associated with a 10-fold resistance to mitoxantrone in the 8226/MR4 cell line. The reduction in intracellular drug concentration was ATP-dependent and ouabain-insensitive. The 8226/MR4 cell line was 34-fold cross-resistant to the fluorescent aza-anthrapyrazole BBR 3390. The resistance to BBR 3390 coincided with a 50% reduction in intracellular drug concentration. Confocal microscopy using BBR 3390 revealed a 64% decrease in the nuclear:cytoplasmic ratio in the drug-resistant cell line. The reduction in intracellular drug concentration of both mitoxantrone and BBR 3390 was reversed by a novel chemosensitizing agent, fumitremorgin C. In contrast, fumitremorgin C had no effect on resistance to mitoxantrone or BBR 3390 in the P-glycoprotein-positive 8226/DOX6 cell line. Increasing the degree of resistance to mitoxantrone in the 8226 cell line from 10 to 37 times (8226/MR20) did not further reduce the intracellular drug concentration. However, the 8226/MR20 cell line exhibited 88 and 70% reductions in topoisomerase II beta and alpha expression, respectively, compared with the parental drug sensitive cell line. This decrease in topoisomerase expression and activity was not observed in the low-level drug-resistant, 8226/MR4 cell line. These data demonstrate that low-level mitoxantrone resistance is due to the presence of a novel, energy-dependent drug efflux pump similar to P-glycoprotein and multidrug resistance-associated protein. Reversal of resistance by blocking drug efflux with fumitremorgin C should allow for functional analysis of this novel transporter in cancer cell lines or clinical tumor samples. Increased resistance to mitoxantrone may result from reduced intracellular drug accumulation, altered nuclear/cytoplasmic drug distribution, and alterations in topoisomerase II activity.  (+info)

Electrophysiologic effect of enalapril on guinea pig papillary muscles in vitro. (6/3013)

AIM: To study the direct effect of enalapril on cellular electrophysiology of myocardium. METHODS: Conventional microelectrodes technique was used to record the action potentials (AP) of guinea pig papillary muscles. RESULTS: Enalapril caused an increase of the AP amplitude (APA) and the resting potential (RP) in a concentration-dependent manner without any significant change of AP duration, Vmax and overshoot of AP. Superfusion of ouabain 0.5 mumol.L-1 reduced APA and RP, induced stable delayed after-depolarizations (DAD) at different basic cycle lengths (BCL) in a frequency-dependent manner. At BCL 200 ms, the amplitude of DAD was large enough to induce nonsustained triggered activity (TA). In additional presence of enalapril 10 mumol.L-1, the DAD amplitude at 500, 400, 300, and 200 ms were decreased from 5.3 +/- 2.3, 5.9 +/- 2.8, 7.4 +/- 2.1, and 8.9 +/- 1.3 to 2.6 +/- 0.7, 3.1 +/- 1.0, 3.7 +/- 1.5, and 5.3 +/- 1.1 (mV) respectively, all P < 0.01. The compensation intervals were increased in a similar frequency-dependent manner. The number of TA induced at BCL 200 ms was decreased from 3.6 +/- 0.7 to 0.8 +/- 0.2 (P < 0.05). CONCLUSION: Enalapril directly inhibits DAD and TA induced by ouabain through increasing RP and APA, which may contribute to its anti-arrhythmic effect.  (+info)

Role of K+ channels in A2A adenosine receptor-mediated dilation of the pressurized renal arcuate artery. (7/3013)

1. Adenosine A2A receptor-mediated renal vasodilation was investigated by measuring the lumenal diameter of pressurized renal arcuate arteries isolated from the rabbit. 2. The selective A2A receptor agonist CGS21680 dilated the arteries with an EC50 of 130 nM. The CGS21680-induced vasodilation was, on average, 34% less in endothelium-denuded arteries. 3. The maximum response and the EC50 for CGS21680-induced vasodilation in endothelium-intact arteries were not significantly affected by incubation with the K+ channel blockers apamin (100 nM), iberiotoxin (100 nM), 3,4-diaminopyridine (1 mM), glibenclamide (1 microM) or Ba2+ (10 microM). However, a cocktail mixture of these blockers did significantly inhibit the maximum response by almost 40%, and 1 mM Ba2+ alone or 1 mM Ba2+ in addition to the cocktail inhibited the maximum CGS21680-response by 58% and about 75% respectively. 4. CGS21680-induced vasodilation was strongly inhibited when the extracellular K+ level was raised to 20 mM even though the dilator response to 1 microM levcromakalim, a K(ATP) channel opener drug, was unaffected. 5. CGS21680-induced vasodilation was inhibited by 10 microM ouabain, an inhibitor of Na+/K(+)-ATPase, but ouabain had a similar inhibitory effect on vasodilation induced by 30 nM nicardipine (a dihydropyridine Ca2+ antagonist) or 1 microM levcromakalim. 6. The data suggest that K+ channel activation does play a role in A(2A) receptor-mediated renal vasodilation. The inhibitory effect of raised extracellular K+ levels on the A(2A) response may be due to K(+)-induced stimulation of Na+/K(+)-ATPase.  (+info)

Excretion of taurocholate from isolated hepatocytes. (8/3013)

Efflux of taurocholate from isolated rat hepatocytes was studied to characterize the mechanism of bile acid secretion. Cells were incubated with taurocholate for 15 min. The amount of the intracellularly accumulated bile acid was directly related to the concentration in the medium. Transfer of the loaded cells from the incubation medium to a medium without taurocholate led to taurocholate efflux. Efflux was saturable, its activation energy amounted to 12 kcal/mol (50 kJ). It was strongly inhibited by the metabolic inhibitor antimycin A and to a lesser extend by the uncoupler carbonylcyanide-m-chlorophenylhydrazone. Dinitrofluorobenzene and mersalyl, reagents which react with amino acids, inhibited efflux by about 30% when applied at concentrations of 50 muM. Ouabain increased the rate of efflux. The observations indicate that secretory functions are maintained in isolated liver cells.  (+info)

Ouabain is defined as a cardiac glycoside, a type of steroid, that is found in the seeds and roots of certain plants native to Africa. It is used in medicine as a digitalis-like agent to increase the force of heart contractions and slow the heart rate, particularly in the treatment of congestive heart failure and atrial fibrillation. Ouabain functions by inhibiting the sodium-potassium pump (Na+/K+-ATPase) in the cell membrane, leading to an increase in intracellular sodium and calcium ions, which ultimately enhances cardiac muscle contractility. It is also known as g-strophanthin or ouabaine.

Sodium-Potassium-Exchanging ATPase (also known as Na+/K+ ATPase) is a type of active transporter found in the cell membrane of many types of cells. It plays a crucial role in maintaining the electrochemical gradient and membrane potential of animal cells by pumping sodium ions (Na+) out of the cell and potassium ions (K+) into the cell, using energy derived from ATP hydrolysis.

This transporter is composed of two main subunits: a catalytic α-subunit that contains the binding sites for Na+, K+, and ATP, and a regulatory β-subunit that helps in the proper targeting and functioning of the pump. The Na+/K+ ATPase plays a critical role in various physiological processes, including nerve impulse transmission, muscle contraction, and kidney function.

In summary, Sodium-Potassium-Exchanging ATPase is an essential membrane protein that uses energy from ATP to transport sodium and potassium ions across the cell membrane, thereby maintaining ionic gradients and membrane potentials necessary for normal cellular function.

Sodium is an essential mineral and electrolyte that is necessary for human health. In a medical context, sodium is often discussed in terms of its concentration in the blood, as measured by serum sodium levels. The normal range for serum sodium is typically between 135 and 145 milliequivalents per liter (mEq/L).

Sodium plays a number of important roles in the body, including:

* Regulating fluid balance: Sodium helps to regulate the amount of water in and around your cells, which is important for maintaining normal blood pressure and preventing dehydration.
* Facilitating nerve impulse transmission: Sodium is involved in the generation and transmission of electrical signals in the nervous system, which is necessary for proper muscle function and coordination.
* Assisting with muscle contraction: Sodium helps to regulate muscle contractions by interacting with other minerals such as calcium and potassium.

Low sodium levels (hyponatremia) can cause symptoms such as confusion, seizures, and coma, while high sodium levels (hypernatremia) can lead to symptoms such as weakness, muscle cramps, and seizures. Both conditions require medical treatment to correct.

Potassium is a essential mineral and an important electrolyte that is widely distributed in the human body. The majority of potassium in the body (approximately 98%) is found within cells, with the remaining 2% present in blood serum and other bodily fluids. Potassium plays a crucial role in various physiological processes, including:

1. Regulation of fluid balance and maintenance of normal blood pressure through its effects on vascular tone and sodium excretion.
2. Facilitation of nerve impulse transmission and muscle contraction by participating in the generation and propagation of action potentials.
3. Protein synthesis, enzyme activation, and glycogen metabolism.
4. Regulation of acid-base balance through its role in buffering systems.

The normal serum potassium concentration ranges from 3.5 to 5.0 mEq/L (milliequivalents per liter) or mmol/L (millimoles per liter). Potassium levels outside this range can have significant clinical consequences, with both hypokalemia (low potassium levels) and hyperkalemia (high potassium levels) potentially leading to serious complications such as cardiac arrhythmias, muscle weakness, and respiratory failure.

Potassium is primarily obtained through the diet, with rich sources including fruits (e.g., bananas, oranges, and apricots), vegetables (e.g., leafy greens, potatoes, and tomatoes), legumes, nuts, dairy products, and meat. In cases of deficiency or increased needs, potassium supplements may be recommended under the guidance of a healthcare professional.

Cardiac glycosides are a group of naturally occurring compounds that have a toxic effect on the heart. They are found in certain plants, including foxglove and lily of the valley, as well as in some toads and beetles. The most well-known cardiac glycoside is digoxin, which is derived from the foxglove plant and is used as a medication to treat heart failure and atrial arrhythmias.

Cardiac glycosides work by inhibiting the sodium-potassium pump in heart muscle cells, leading to an increase in intracellular calcium levels. This increases the force of heart contractions, which can be beneficial in treating heart failure. However, if the dose is too high, cardiac glycosides can also cause dangerous arrhythmias and even death.

It's important for healthcare professionals to carefully monitor patients taking cardiac glycosides, as the therapeutic and toxic doses are very close together. Additionally, certain medications and medical conditions can interact with cardiac glycosides and increase the risk of toxicity.

Biological transport, active is the process by which cells use energy to move materials across their membranes from an area of lower concentration to an area of higher concentration. This type of transport is facilitated by specialized proteins called transporters or pumps that are located in the cell membrane. These proteins undergo conformational changes to physically carry the molecules through the lipid bilayer of the membrane, often against their concentration gradient.

Active transport requires energy because it works against the natural tendency of molecules to move from an area of higher concentration to an area of lower concentration, a process known as diffusion. Cells obtain this energy in the form of ATP (adenosine triphosphate), which is produced through cellular respiration.

Examples of active transport include the uptake of glucose and amino acids into cells, as well as the secretion of hormones and neurotransmitters. The sodium-potassium pump, which helps maintain resting membrane potential in nerve and muscle cells, is a classic example of an active transporter.

Digoxin is a medication that belongs to a class of drugs called cardiac glycosides. It is used to treat various heart conditions, such as heart failure and atrial fibrillation, by helping the heart beat stronger and more regularly. Digoxin works by inhibiting the sodium-potassium pump in heart muscle cells, which leads to an increase in intracellular calcium and a strengthening of heart contractions. It is important to monitor digoxin levels closely, as too much can lead to toxicity and serious side effects.

I'm sorry for any confusion, but "Rubidium" is not a medical term. It is a chemical element with the symbol Rb and atomic number 37. Rubidium is a soft, silvery-white metal that is highly reactive and flammable. It is found in trace amounts in minerals such as leucite and pollucite.

While rubidium itself does not have a direct medical application, its radioisotopes (such as rubidium-82) are used in medical imaging, particularly in positron emission tomography (PET) scans, to study heart function and blood flow. However, the term "Rubidium" itself is not used in a medical context to define a condition or disease.

Digitoxin is a cardiac glycoside drug that is derived from the foxglove plant (Digitalis lanata). It is used in the treatment of various heart conditions, particularly congestive heart failure and certain types of arrhythmias. Digitoxin works by increasing the force of heart muscle contractions and slowing the heart rate, which helps to improve the efficiency of the heart's pumping action.

Like other cardiac glycosides, digitoxin inhibits the sodium-potassium pump in heart muscle cells, leading to an increase in intracellular calcium levels and a strengthening of heart muscle contractions. However, digitoxin has a longer half-life than other cardiac glycosides such as digoxin, which means that it stays in the body for a longer period of time and may require less frequent dosing.

Digitoxin is available in tablet form and is typically prescribed at a low dose, with regular monitoring of blood levels to ensure safe and effective use. Common side effects of digitoxin include nausea, vomiting, diarrhea, and dizziness. In rare cases, it can cause more serious side effects such as arrhythmias or toxicity, which may require hospitalization and treatment with medications or other interventions.

Rubidium radioisotopes are unstable isotopes of the element rubidium that emit radiation as they decay towards a stable state. This means that rubidium atoms with an excess of neutrons in their nuclei will emit subatomic particles (such as beta particles) and/or gamma rays to transform into a more stable form, often resulting in a different element.

Rubidium has two common radioisotopes: Rubidium-82 and Rubidium-87.

* Rubidium-82 (^82Rb) is a positron emitter with a half-life of 1.25 minutes, which is commonly used in medical imaging for myocardial perfusion studies to assess blood flow to the heart muscle. It is produced by the decay of Strontium-82 (^82Sr), typically via a generator system in the hospital's radiopharmacy.
* Rubidium-87 (^87Rb) has a half-life of 48.8 billion years, which is much longer than the age of the universe. It occurs naturally and decays into Strontium-87 (^87Sr) through beta decay. This process can be used for geological dating purposes in rocks and minerals.

It's important to note that radioisotopes, including rubidium isotopes, should only be handled by trained professionals in controlled environments due to their radiation hazards.

Sodium is an element with the atomic number 11 and symbol Na. An isotope of an element is a variant that has the same number of protons in its nucleus (and therefore the same atomic number), but a different number of neutrons, resulting in a different atomic mass.

There are several isotopes of sodium, including:

* Sodium-23: This is the most common isotope, making up about 99.9% of natural sodium. It has 11 protons and 12 neutrons in its nucleus, giving it an atomic mass of 23.00 u (unified atomic mass units).
* Sodium-22: This is a radioactive isotope that decays via beta plus decay to neon-22 with a half-life of about 2.6 years. It has 11 protons and 11 neutrons in its nucleus, giving it an atomic mass of 22.00 u.
* Sodium-24: This is another radioactive isotope that decays via beta minus decay to magnesium-24 with a half-life of about 15 hours. It has 11 protons and 13 neutrons in its nucleus, giving it an atomic mass of 24.00 u.

Isotopes of sodium are used in various applications, including as tracers in medical research and as a source of radiation in cancer treatment.

Strophanthins are a type of cardiac glycosides that are derived from the seeds of various plants in the genus Strophanthus. These compounds have been used in traditional medicine for their cardiotonic and arrhythmogenic effects. They work by inhibiting the sodium-potassium pump in heart muscle cells, which leads to an increase in intracellular calcium levels and a strengthening of heart contractions. Strophanthins are also known to have a negative chronotropic effect, meaning they can slow down the heart rate. They are used in some countries for the treatment of heart failure and arrhythmias, but their use is limited due to their narrow therapeutic index and potential toxicity.

Cardiotonic agents are a type of medication that have a positive inotropic effect on the heart, meaning they help to improve the contractility and strength of heart muscle contractions. These medications are often used to treat heart failure, as they can help to improve the efficiency of the heart's pumping ability and increase cardiac output.

Cardiotonic agents work by increasing the levels of calcium ions inside heart muscle cells during each heartbeat, which in turn enhances the force of contraction. Some common examples of cardiotonic agents include digitalis glycosides (such as digoxin), which are derived from the foxglove plant, and synthetic medications such as dobutamine and milrinone.

While cardiotonic agents can be effective in improving heart function, they can also have potentially serious side effects, including arrhythmias, electrolyte imbalances, and digestive symptoms. As a result, they are typically used under close medical supervision and their dosages may need to be carefully monitored to minimize the risk of adverse effects.

Digitalis glycosides are a type of cardiac glycoside that are derived from the foxglove plant (Digitalis purpurea) and related species. These compounds have a steroidal structure with a lactone ring attached to the molecule, which is responsible for their positive inotropic effects on the heart.

The two main digitalis glycosides used clinically are digoxin and digitoxin. They work by inhibiting the sodium-potassium pump in cardiac muscle cells, leading to an increase in intracellular calcium levels and a subsequent enhancement of myocardial contractility. This makes them useful in the treatment of heart failure and atrial arrhythmias such as atrial fibrillation.

However, digitalis glycosides have a narrow therapeutic index, meaning that there is only a small difference between their therapeutic and toxic doses. Therefore, they must be administered with caution and patients should be closely monitored for signs of toxicity such as nausea, vomiting, visual disturbances, and cardiac arrhythmias.

Saponins are a type of naturally occurring chemical compound found in various plants, including soapwords, ginseng, and many others. They are known for their foaming properties, similar to that of soap, which gives them their name "saponin" derived from the Latin word "sapo" meaning soap.

Medically, saponins have been studied for their potential health benefits, including their ability to lower cholesterol levels, reduce inflammation, and boost the immune system. However, they can also have toxic effects in high concentrations, causing gastrointestinal disturbances and potentially damaging red blood cells.

Saponins are typically found in the cell walls of plants and can be extracted through various methods for use in pharmaceuticals, food additives, and cosmetics.

Bufanolides are a type of chemical compound that are found naturally in certain plants and animals, particularly in the skin secretions of toads from the genus Bufo. These compounds have a steroid-like structure and can have various pharmacological effects, such as diuretic, anti-inflammatory, and cardiotonic activities. Some bufanolides are also known to have toxic or hallucinogenic properties.

In medical contexts, bufanolides may be studied for their potential therapeutic uses, but they are not currently used as medications in clinical practice due to their narrow therapeutic index and potential toxicity. It is important to note that the use of toad secretions or products containing bufanolides as alternative medicine or recreational drugs can be dangerous and is not recommended.

Ethacrynic acid is a loop diuretic drug that is primarily used to treat edema (swelling) associated with heart failure, liver cirrhosis, and kidney disease. It works by increasing the excretion of water and sodium in the urine, which helps reduce fluid buildup in the body. Ethacrynic acid is also known as a "high-ceiling" diuretic because it has a strong effect on urine production.

The drug is available in oral form and is typically taken once or twice a day, depending on the severity of the edema and the patient's response to treatment. Ethacrynic acid can have side effects, including hearing loss, kidney damage, and electrolyte imbalances, so it is important for patients to be monitored closely by their healthcare provider while taking this medication.

It is worth noting that ethacrynic acid is not as commonly used as other loop diuretics, such as furosemide or torsemide, due to its higher risk of side effects and the availability of safer alternatives.

Lithium is not a medical term per se, but it is a chemical element with symbol Li and atomic number 3. In the field of medicine, lithium is most commonly referred to as a medication, specifically as "lithium carbonate" or "lithium citrate," which are used primarily to treat bipolar disorder. These medications work by stabilizing mood and reducing the severity and frequency of manic episodes.

Lithium is a naturally occurring substance, and it is an alkali metal. In its elemental form, lithium is highly reactive and flammable. However, when combined with carbonate or citrate ions to form lithium salts, it becomes more stable and safe for medical use.

It's important to note that lithium levels in the body must be closely monitored while taking this medication because too much lithium can lead to toxicity, causing symptoms such as tremors, nausea, diarrhea, and in severe cases, seizures, coma, or even death. Regular blood tests are necessary to ensure that lithium levels remain within the therapeutic range.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

Cardanolides are a type of steroid compound that are found in certain plants, particularly in the family Apocynaceae. These compounds have a characteristic structure that includes a five-membered lactone ring attached to a steroid nucleus, and they are known for their ability to inhibit the sodium-potassium pump (Na+/K+-ATPase) in animal cells. This property makes cardanolides toxic to many organisms, including humans, and they have been used as heart poisons and insecticides.

One of the most well-known cardanolides is ouabain, which is found in the seeds of several African plants and has been used traditionally as a medicine for various purposes, including as a heart stimulant and a poison for hunting. Other examples of cardanolides include digoxin and digitoxin, which are derived from the foxglove plant (Digitalis purpurea) and are used in modern medicine to treat heart failure and atrial arrhythmias.

It's worth noting that while cardanolides have important medical uses, they can also be highly toxic if ingested or otherwise introduced into the body in large amounts. Therefore, it's essential to use these compounds only under the supervision of a qualified healthcare professional.

I must clarify that the term "Guinea Pigs" is not typically used in medical definitions. However, in colloquial or informal language, it may refer to people who are used as the first to try out a new medical treatment or drug. This is known as being a "test subject" or "in a clinical trial."

In the field of scientific research, particularly in studies involving animals, guinea pigs are small rodents that are often used as experimental subjects due to their size, cost-effectiveness, and ease of handling. They are not actually pigs from Guinea, despite their name's origins being unclear. However, they do not exactly fit the description of being used in human medical experiments.

Potassium isotopes refer to variants of the element potassium that have different numbers of neutrons in their atomic nuclei, while having the same number of protons, which defines the element. The most common and stable potassium isotope is potassium-39 (39K), which contains 19 neutrons and 20 protons. However, there are also other naturally occurring potassium isotopes, including potassium-40 (40K) with 21 neutrons and potassium-41 (41K) with 22 neutrons.

Potassium-40 is a radioactive isotope that undergoes both beta decay and electron capture, making it useful for various scientific applications such as dating rocks and determining the age of archaeological artifacts. It has a half-life of approximately 1.25 billion years.

In medical contexts, potassium isotopes may be used in diagnostic tests or therapeutic procedures, such as positron emission tomography (PET) scans, where radioactive potassium-40 or other radioisotopes are introduced into the body to help visualize and diagnose various conditions. However, it's important to note that the use of potassium isotopes in medical settings is relatively rare due to the availability of other more commonly used radioisotopes.

Membrane potential is the electrical potential difference across a cell membrane, typically for excitable cells such as nerve and muscle cells. It is the difference in electric charge between the inside and outside of a cell, created by the selective permeability of the cell membrane to different ions. The resting membrane potential of a typical animal cell is around -70 mV, with the interior being negative relative to the exterior. This potential is generated and maintained by the active transport of ions across the membrane, primarily through the action of the sodium-potassium pump. Membrane potentials play a crucial role in many physiological processes, including the transmission of nerve impulses and the contraction of muscle cells.

Amiloride is a medication that belongs to a class of drugs called potassium-sparing diuretics. It works by preventing the reabsorption of salt and water in the kidneys, which helps to increase urine output and decrease fluid buildup in the body. At the same time, amiloride also helps to preserve the level of potassium in the body, which is why it is known as a potassium-sparing diuretic.

Amiloride is commonly used to treat high blood pressure, heart failure, and edema (fluid buildup) in the body. It is available in tablet form and is typically taken once or twice a day, with or without food. Common side effects of amiloride include headache, dizziness, and stomach upset.

It's important to note that amiloride can interact with other medications, including some over-the-counter products, so it's essential to inform your healthcare provider of all the medications you are taking before starting amiloride therapy. Additionally, regular monitoring of blood pressure, kidney function, and electrolyte levels is necessary while taking this medication.

Enzyme inhibitors are substances that bind to an enzyme and decrease its activity, preventing it from catalyzing a chemical reaction in the body. They can work by several mechanisms, including blocking the active site where the substrate binds, or binding to another site on the enzyme to change its shape and prevent substrate binding. Enzyme inhibitors are often used as drugs to treat various medical conditions, such as high blood pressure, abnormal heart rhythms, and bacterial infections. They can also be found naturally in some foods and plants, and can be used in research to understand enzyme function and regulation.

Guanabenz is not a medical condition, it's a medication. Here's the definition:

Guanabenz (brand name Wytensin) is a centrally acting antihypertensive agent, primarily used for the treatment of hypertension. It belongs to the class of drugs known as "central alpha-2 adrenergic agonists." Guanabenz works by mimicking the effects of natural neurotransmitters in your body to reduce nerve impulses that cause blood vessels to constrict, thereby promoting vasodilation and lowering blood pressure.

Please consult a healthcare professional or refer to medical resources for more detailed information about specific medications and their uses, side effects, and interactions.

Bumetanide is a loop diuretic medication that is primarily used to treat fluid buildup and swelling caused by various medical conditions, such as heart failure, liver cirrhosis, and kidney disease. It works by increasing the excretion of salt and water from the body through urination.

The increased urine output helps reduce the amount of fluid in the body, which can help alleviate symptoms such as shortness of breath, weight gain, and swelling in the legs, ankles, and feet. Bumetanide is a potent diuretic and should be used under the close supervision of a healthcare provider to monitor its effects on the body's electrolyte balance and fluid levels.

Like other loop diuretics, bumetanide can cause side effects such as dehydration, electrolyte imbalances, hearing loss, and kidney damage if used inappropriately or in excessive doses. It is important to follow the prescribed dosage regimen and inform your healthcare provider of any changes in your health status while taking this medication.

Adenosine triphosphatases (ATPases) are a group of enzymes that catalyze the conversion of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and inorganic phosphate. This reaction releases energy, which is used to drive various cellular processes such as muscle contraction, transport of ions across membranes, and synthesis of proteins and nucleic acids.

ATPases are classified into several types based on their structure, function, and mechanism of action. Some examples include:

1. P-type ATPases: These ATPases form a phosphorylated intermediate during the reaction cycle and are involved in the transport of ions across membranes, such as the sodium-potassium pump and calcium pumps.
2. F-type ATPases: These ATPases are found in mitochondria, chloroplasts, and bacteria, and are responsible for generating a proton gradient across the membrane, which is used to synthesize ATP.
3. V-type ATPases: These ATPases are found in vacuolar membranes and endomembranes, and are involved in acidification of intracellular compartments.
4. A-type ATPases: These ATPases are found in the plasma membrane and are involved in various functions such as cell signaling and ion transport.

Overall, ATPases play a crucial role in maintaining the energy balance of cells and regulating various physiological processes.

Furosemide is a loop diuretic medication that is primarily used to treat edema (fluid retention) associated with various medical conditions such as heart failure, liver cirrhosis, and kidney disease. It works by inhibiting the sodium-potassium-chloride cotransporter in the ascending loop of Henle in the kidneys, thereby promoting the excretion of water, sodium, and chloride ions. This increased urine output helps reduce fluid accumulation in the body and lower blood pressure.

Furosemide is also known by its brand names Lasix and Frusid. It can be administered orally or intravenously, depending on the patient's condition and the desired rate of diuresis. Common side effects include dehydration, electrolyte imbalances, hearing loss (in high doses), and increased blood sugar levels.

It is essential to monitor kidney function, electrolyte levels, and fluid balance while using furosemide to minimize potential adverse effects and ensure appropriate treatment.

Biological transport refers to the movement of molecules, ions, or solutes across biological membranes or through cells in living organisms. This process is essential for maintaining homeostasis, regulating cellular functions, and enabling communication between cells. There are two main types of biological transport: passive transport and active transport.

Passive transport does not require the input of energy and includes:

1. Diffusion: The random movement of molecules from an area of high concentration to an area of low concentration until equilibrium is reached.
2. Osmosis: The diffusion of solvent molecules (usually water) across a semi-permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
3. Facilitated diffusion: The assisted passage of polar or charged substances through protein channels or carriers in the cell membrane, which increases the rate of diffusion without consuming energy.

Active transport requires the input of energy (in the form of ATP) and includes:

1. Primary active transport: The direct use of ATP to move molecules against their concentration gradient, often driven by specific transport proteins called pumps.
2. Secondary active transport: The coupling of the movement of one substance down its electrochemical gradient with the uphill transport of another substance, mediated by a shared transport protein. This process is also known as co-transport or counter-transport.

... is no longer approved for use in the USA. In France and Germany, however, intravenous ouabain has a long history in the ... Ouabain was seen as a possible treatment for certain cardiac conditions. K-Strophanthidin "ouabain" in the World English ... Hence, it was suggested that some assays for endogenous ouabain detected other compounds or failed to detect ouabain at all. ... Lewis LK, Yandle TG, Hilton PJ, Jensen BP, Begg EJ, Nicholls MG (October 2014). "Endogenous ouabain is not ouabain". ...
"The stimulation of phosphate of ouabain binding to the sodium pump..." The Journal of Physiology. 252 (2). 1 November 1975. doi ... Chipperfield, A. R.; Whittam, R. (1973). "Ouabain Binding to the Sodium Pump". Nature. 242 (5392): 62-63. Bibcode:1973Natur.242 ...
Some of the chemicals in the plants are used to produce the drug ouabain, which was taken as a cardiac stimulant to treat heart ... ouabain), k-strophanthin, and e-strophanthin. As ordinarily administered, the drug acts on the heart before influencing any ...
"Resolution of the insect ouabain paradox". Proceedings of the National Academy of Sciences of the United States of America. 101 ...
Furthermore, an ouabain block of Na⁺-K⁺ pumps in the cerebellum of a live mouse results in it displaying ataxia and dystonia. ... However, upon subsequent ouabain binding, the Src kinase domain is released and then activated. Based on this scenario, NaKtide ... July 2009). "NaKtide, a Na/K-ATPase-derived peptide Src inhibitor, antagonizes ouabain-activated signal transduction in ... Blaustein MP, Hamlyn JM (December 2010). "Signaling mechanisms that link salt retention to hypertension: endogenous ouabain, ...
Smith, LL (2004). "Oxygen, oxysterols, ouabain, and ozone: a cautionary tale". Free Radical Biology & Medicine. 37 (3): 318-24 ...
It is the aglycone of k-strophanthin, an analogue of ouabain. k-strophanthin is found in the ripe seeds of Strophanthus kombé ... Bruno Kisch (New York City) noted that ouabain (strophanthin-G) has a positive ionotropic activity and faster onset than ... Song H, Karashima E, Hamlyn JM, Blaustein MP (March 2014). "Ouabain-digoxin antagonism in rat arteries and neurones". The ... Ouabain Digoxin Myocardial infarction Toxicity Detoxification Muscle contraction Cardiac glycosides Sigma-Aldrich. " ...
Its sap contains the deadly cardiotoxic glycoside ouabain. The sap is among the most commonly used in arrow poisons, including ...
Ferrari, Patrizia; Ferrandi, Mara; Valentini, Giovanni; Bianchi, Giuseppe (2006). "Rostafuroxin: An ouabain antagonist that ... Ferrari, Patrizia (2010). "Rostafuroxin: An ouabain-inhibitor counteracting specific forms of hypertension". Biochimica et ... corrects renal and vascular Na+-K+- ATPase alterations in ouabain and adducin-dependent hypertension". American Journal of ...
Post asked whether the enzyme was inhibited by ouabain. At this stage Skou was unaware that ouabain inhibited the pump, but he ... Ouabain did indeed inhibit the enzyme, thus establishing a link between the enzyme and the sodium-potassium pump. Following the ... and in his research he had made use of a substance called ouabain (or g-strophanthin) which had recently been shown to inhibit ...
Berova, Nina (1993). "Physicochemical characterization of a ouabain isomer isolated from bovine hypothalamus". PNAS. 90 (17): ...
Pitts BJ, Meyerson LR (1981). "Inhibition of Na,K-ATPase Activity and Ouabain Binding by Sanguinarine". Drug Development ...
However, a high dose of ouabain can lead to ventricular tachycardia. C. Andreasen, et al. (2006) Mosby Elsevier, Mosby's ... Third degree AV block can be treated with Cilostazol which acts to increase Ventricular escape rate Ouabain infusion decreases ...
This plant contains ouabain, which is a cardiac glycoside, oleander, and milkweeds. Poisoned arrows are also still used in the ...
Habermann E, Chhatwal GS (1 May 1982). "Ouabain inhibits the increase due to palytoxin of cation permeability of erythrocytes ... where it interacts with the natural binding site of ouabain with very high affinity. Na+/K+-ATPase is a transmembrane protein, ...
September 2021). "Ouabain and chloroquine trigger senolysis of BRAF-V600E-induced senescent cells by targeting autophagy". ... ouabain (g-strophanthin) and other strophanthins Digitalis lanata and Digitalis purpurea (Woolly and purple foxglove): digoxin ...
... is observed for lower ouabain concentrations, dystonia is observed at higher ouabain concentrations. Antibodies against ... Indeed, an ouabain block of Na+ -K+ pumps in the cerebellum of a live mouse results in it displaying ataxia and dystonia. ...
May 2020). "Identification of Atovaquone, Ouabain and Mebendazole as FDA-Approved Drugs Targeting SARS-CoV-2". chemRxiv ( ...
September 2021). "Ouabain and chloroquine trigger senolysis of BRAF-V600E-induced senescent cells by targeting autophagy". ...
"Suppression of ouabain-insensitive K-ATPase activity in rabbit nephron segments during chronic hyperkalemia". Renal Physiology ...
1999). "Ouabain-sensitive H,K-ATPase: tissue-specific expression of the mammalian genes encoding the catalytic alpha subunit". ... This gene encodes a catalytic subunit of the ouabain-sensitive H+/K+ -ATPase that catalyzes the hydrolysis of ATP coupled with ... Sverdlov VE, Kostina MB, Modyanov NN (1997). "Genomic organization of the human ATP1AL1 gene encoding a ouabain-sensitive H,K- ... "Genomic organization of the human ATP1AL1 gene encoding a ouabain-sensitive H,K-ATPase". Genomics. 32 (3): 317-27. doi:10.1006/ ...
"Reducing the Late Sodium Current Improves Cardiac Function during Sodium Pump Inhibition by Ouabain". Journal of Pharmacology ...
... resembles very much other glycosides like ouabain and digoxin but has less effect than digoxin. It is however, just ... like its derivate oleandrigenin, a more potent glycoside than ouabain. Oleandrin and its derivate oleandrigenin are formed in ...
Ataxia is observed for lower ouabain concentrations, dystonia is observed at higher ouabain concentrations. A mutation in the ... Indeed, an ouabain block of Na+ -K+ pumps in the cerebellum of a live mouse results in it displaying ataxia and dystonia. ...
"Reducing the Late Sodium Current Improves Cardiac Function during Sodium Pump Inhibition by Ouabain". Journal of Pharmacology ...
The drugs were later publicly identified as digitalis and ouabain, both cardenolide-type cardiac glycosides.) Hicks noted the ...
Furthermore, the presence of a sugar group in ouabain and the absence of one in arenobufagin suggests that it may me more ... along with ouabain. It has been suggested that uncharged and non-polar amino acids may participate in the binding of ... lipophilic that ouabain and as such form a more stable complex with the Na+-K+ pump. Besides its effects on the Na+-K+ pump, ...
"Sodium-dependence and ouabain-sensitivity of the synthesis of dopamine in renal tissues of the rat". Br. J. Pharmacol. 105 (4 ...
They tipped their arrows with ouabain, a poison which caused death by cardiac arrest or respiratory failure. The Maya homeland ...
NEM activates ouabain-insensitive Cl-dependent K efflux in low K sheep and goat red blood cells. This discovery contributed to ...
Ouabain is no longer approved for use in the USA. In France and Germany, however, intravenous ouabain has a long history in the ... Ouabain was seen as a possible treatment for certain cardiac conditions. K-Strophanthidin "ouabain" in the World English ... Hence, it was suggested that some assays for endogenous ouabain detected other compounds or failed to detect ouabain at all. ... Lewis LK, Yandle TG, Hilton PJ, Jensen BP, Begg EJ, Nicholls MG (October 2014). "Endogenous ouabain is not ouabain". ...
Dive into the research topics of Diminished ouabain sensitivity in aged myocardium. Together they form a unique fingerprint. ...
Ouabain ( Strophanthus gratus) * Lily-of-the-valley ( Convallaria majalis) * Common oleander ( Nerium oleander) ...
Open the PDF for Urinary Excretion of Endogenous Ouabain-Like Substance in Furosemide-Treated Neonates: Its Relation to Renal ... View article titled, Urinary Excretion of Endogenous Ouabain-Like Substance in Furosemide-Treated Neonates: Its Relation to ... Urinary Excretion of Endogenous Ouabain-Like Substance in Furosemide-Treated Neonates: Its Relation to Renal Excretory Pattern ...
... and ouabain (O; basolateral; 10?4M). Changes in lactate dehydrogenase (LDH) levels in apical medium also were assessed after ...
Using ouabain in our mouse model should allow to demonstrate that the reported recovery after afferent ablation (Chambers et al ...
Na+/K+-ATPase pump-based inhibitors bufalin and ouabain restricted MERS-CoV infection (Burkard et al., 2014; Burkard et al., ...
In the present study, inhibition of the Na+, K(+)-ATPase with 10 microM ouabain for 30 min at 37 degrees C led to acute ... Protection against ouabain suggests that hypothermia can intervene at steps subsequent to decreased Na+, K(+)-ATPase activity. ... Swelling and increased gamma-aminobutyric acid release were first evident at 15 min of incubation with ouabain at 37 degrees C ... This protection was independent of an involvement with ATP loss, because ouabain treatment did not reduce ATP levels. ...
Interrupting doses of ouabain in the isolated AV node preparation of II and III and in the pithed donor dog heart were almost ... Ouabain was continuously infused either selectively into the AV node artery (I) or systemically i. v. into the pentobarbital- ... Effects of ouabain on atrioventricular (AV) conduction were studied by using the canine excised, blood-perfused AV node ... Effects of Ouabain on Atrioventricular Conduction: Simultaneous Observation in the Isolated AV Node Preparation and the in Situ ...
K-ATPase activity measured either as ouabain-suppressible ATP hydrolysis in rat liver or kidney homogenates, or as ouabain- ...
It is known that the effect of [3H]-ouabain at 10−9M (compared with [3H]-ouabain at 10−4M) has no different effect on Na+/K+ ... The effect of [3H]-ouabain at 10−4M on water content and number of ouabain molecules in brain cortex, liver and spleen tissues ... The effect of [3H]-ouabain at 10−9M on water content and number of ouabain molecules in brain cortex, liver and spleen tissues ... The effect of 10−9 M ouabain on hydration and ouabain binding in brain cortex, liver and spleen tissues. Black bars on (a)-(c) ...
Ouabain ELISA Kit. ECP7911 Genovis AB 96 Tests. EUR 713 /* The Modal (background) */ .modal { display: none; /* Hidden by ...
The Na+, K+, and Cl- Content of Goose Salt Gland Slices and the Effects of Acetylcholine and Ouabain J Gen Physiol (October, ...
... a novel toxicity response in neuro-2a cells consisting of the recovery of the cell viability in the presence of ouabain and ... a novel toxicity response in neuro-2a cells consisting of the recovery of the cell viability in the presence of ouabain and ...
Spontaneous voltage oscillations in rat papillary muscles exposed to ouabain. Nordin, C., Kay, M. & Aronson, R., 1984, In: ... Altered myocardial response to ouabain in diabetic rats: Mechanics and electrophysiology. Fein, F. S., Aronson, R. S., Nordin, ... Triggered activity induced by K+ -free, Na+-deficient solution in guinea pig ventricular muscle: The effects of ouabain, ... Arrhythmogenic interaction between low potassium and ouabain in isolated guinea‐pig ventricular myocytes.. Aronson, R. S. & ...
S5). An increase in [K⁺]o had a similar effect on latency, like ouabain, followed by slow iridal contraction (Figs. 3C, 3D). ... 3C, 3D). Furthermore, iridal contraction in the presence of ouabain was slower than control irises (Figs. 3C, 3D) and did not ... Inhibition of Na⁺/K⁺-ATPase by ouabain during dark incubation ON, followed by stimulation with ACh, caused an increase in ... ouabain (100 µM), which suppress Na⁺ efflux and K⁺ influx, was added to Tyrodes solution before dark incubation ON. During ...
O Words: The complete list of English words that start with O. Here you can find all the words that begin with the letter O.
Other linked groups (aglycones) include steroids with hydroxyl groups (eg, cardiac glycosides such as digitalis or ouabain) or ...
Strophanthus gratus seeds, OUABAIN Content 0.017 Kilogramm (€2,350.00 * / 1 Kilogramm) €39.95 * Order number: 6697 ...
... ouabain), Apocynum cannabinum (dogbane), and Cheiranthus cheiri (wallflower). In addition, the venom gland of cane toad (Bufo ...
Isc persists in the absence of a transmural electrochemical gradient for Li and is abolished by amiloride or ouabain. In the ... Isc persists in the absence of a transmural electrochemical gradient for Li and is abolished by amiloride or ouabain. In the ... Isc persists in the absence of a transmural electrochemical gradient for Li and is abolished by amiloride or ouabain. In the ... Isc persists in the absence of a transmural electrochemical gradient for Li and is abolished by amiloride or ouabain. In the ...
presence and absence of ouabain (Fig. 4A). A regression of ion transport rates on size shows that growing sea urchin larvae ... of 2 mM ouabain. (B) In vivo Na+,K+-ATPase activity under control (closed symbols) and seawater acidification (open symbols) ...
Ouabain also eliminates senescent preneoplastic cells. Our findings suggest that cardiac glycosides may be effective anti- ... Here, we show that the cardiac glycoside, ouabain, is a senolytic agent with broad activity. Senescent cells are sensitized to ... ouabain-induced apoptosis, a process mediated in part by induction of the pro-apoptotic Bcl2-family protein NOXA. We show that ...
... while increasing Rt in response to ouabain at 0 wk and NPPB at 8 wk compared to STD+AIR. HFWD+SIL increased basal ISC at 0 and ... and ouabain (Na+ , K+ -pump blocker; basolateral). Airway hyperresponsiveness is associated with obesity and pulmonary diseases ... 4 wk, caused reduction in Cl- transport and Na+ , K+ -pump activity at 4 wk, while reducing Rt in response to ouabain at 4 wk ...
Dysfunction of ouabain-induced cardiac contractility in mice with heart-specific ablation of Na,K-ATPase beta1-subunit. J Mol ...
  • I sc persists in the absence of a transmural electrochemical gradient for Li and is abolished by amiloride or ouabain. (elsevierpure.com)
  • Inhibition of Na+/H+ exchange with amiloride (1 mM) had no effect on the ouabain-induced acidification. (furg.br)
  • Hence, it was suggested that some assays for endogenous ouabain detected other compounds or failed to detect ouabain at all. (wikipedia.org)
  • In the present study, inhibition of the Na+, K(+)-ATPase with 10 microM ouabain for 30 min at 37 degrees C led to acute toxicity that was similar to the toxicity produced by severe metabolic stress, i.e., primarily excitotoxic and mediated by NMDA receptors and secondarily involving non-NMDA receptors and voltage-dependent Na+ channels. (aspetjournals.org)
  • Previous studies in chick embryo cardiac myocytes have shown that the inhibition of Na+/K+-ATPase with ouabain induces cell shrinkage in an isosmotic environment (290 mOsm). (furg.br)
  • Ouabain is a cardiac glycoside and in lower doses, can be used medically to treat hypotension and some arrhythmias. (wikipedia.org)
  • Interrupting doses of ouabain in the isolated AV node preparation of II and III and in the pithed donor dog heart were almost similar, all of which were significantly larger than that in pentobarbital-anesthetized dog heart. (go.jp)
  • Ouabain is a cardiac glycoside that acts by inhibiting the Na+/K+-ATPase sodium-potassium ion pump (but it is not selective). (wikipedia.org)
  • The change in ionic gradients caused by ouabain can also affect the membrane voltage of the cell and result in cardiac arrhythmias. (wikipedia.org)
  • Other linked groups (aglycones) include steroids with hydroxyl groups (eg, cardiac glycosides such as digitalis or ouabain) or other chemicals (eg, antibiotics such as streptomycin). (medquizzes.net)
  • Cardiac glycosides are found in a diverse group of plants including Digitalis purpurea and Digitalis lanata (foxgloves), Nerium oleander (common oleander), Thevetia peruviana (yellow oleander), Convallaria majalis (lily of the valley), Urginea maritima and Urginea indica (squill), Strophanthus gratus (ouabain), Apocynum cannabinum (dogbane), and Cheiranthus cheiri (wallflower). (medscape.com)
  • An overdose of ouabain can be detected by the presence of the following symptoms: rapid twitching of the neck and chest musculature, respiratory distress, increased and irregular heartbeat, rise in blood pressure, convulsions, wheezing, clicking, and gasping rattling. (wikipedia.org)
  • Four extracts of F. paulensis exhibited a novel toxicity response in neuro-2a cells consisting of the recovery of the cell viability in the presence of ouabain and veratridine. (lu.se)
  • Yet another argument against the existence of endogenous ouabain was the lack of effect of rostafuroxin (a first generation ouabain receptor antagonist) on blood pressure in an unselected population of hypertensive patients. (wikipedia.org)
  • It is concluded that ouabain depresses directly AV conduction but this effect was modified by sympathetic nerve activity in the nerve-intact animals and also by inherent characteristics of the AV nodal cells. (go.jp)
  • Effects of ouabain on atrioventricular (AV) conduction were studied by using the canine excised, blood-perfused AV node preparations. (go.jp)
  • In France and Germany, however, intravenous ouabain has a long history in the treatment of heart failure, and some continue to advocate its use intravenously and orally in angina pectoris and myocardial infarction despite its poor and variable absorption. (wikipedia.org)
  • This protection was independent of an involvement with ATP loss, because ouabain treatment did not reduce ATP levels. (aspetjournals.org)
  • Additionally, it was suggested that rhamnose, the L-sugar component of ouabain, could not be synthesized within the body despite published data to the contrary. (wikipedia.org)
  • In contrast, in the neonate, ouabain (1-100 nM) enhanced adrenergic induction of N-acetyltransferase activity, and ouabain treatment alone (1-1000 nM) stimulated N-acetyltransferase activity. (nih.gov)
  • It is known that ouabain, a selective inhibitor of Na/K-ATPase, not only can cause the activation of signal cascades, which regulate the cell viability, but also can cause the accumulation of free radicals, which can evoke the oxidative stress. (nih.gov)
  • 9. NaKtide, a Na/K-ATPase-derived peptide Src inhibitor, antagonizes ouabain-activated signal transduction in cultured cells. (nih.gov)
  • Using a low- eld, static gradient system, P(k) data were acquired from ex vivo neonatal mouse spinal cords in three conditions: xed, live, and live whilst treated with ouabain, a sodium-potassium pump inhibitor. (nih.gov)
  • It's been known for a long time that injecting the sodium/potassium pump inhibitor ouabain into the brain can induce seizures in rats," says Clapcote, and it's also known that mice lacking two of three forms of the pump - either the "alpha1" or "alpha2" forms - are free from seizures. (newscientist.com)
  • Here, we show in a longitudinal pharmacological magnetic resonance imaging study that exogenously administered AEA dose-dependently reduced neuronal damage in neonatal rats injected intracerebrally with the Na+/K+-ATPase inhibitor ouabain. (tue.nl)
  • 19. Src-mediated inter-receptor cross-talk between the Na+/K+-ATPase and the epidermal growth factor receptor relays the signal from ouabain to mitogen-activated protein kinases. (nih.gov)
  • Previously, we have shown that ouabain affects the activation of mitogen-activated protein kinases (MAP kinases) ERK1/2, p38, and JNK. (scilifelab.se)
  • Ouabain enhanced apoptosis induced by imatinib in K562/G01 cells not through cell cycle arrest. (ijpsonline.com)
  • Moreover, the long-term incubation with ouabain leads to the cell death by necrosis and apoptosis. (nih.gov)
  • Ouabain-mediated apoptosis and necrosis were also abolished by carnosine. (nih.gov)
  • In our present study, ouabain showed greatly inhibitory effect and significantly reduced half minimal inhibitory concentration of imatinib in K562/ G01 cells, an imatinib-resistant cell line of chronic myeloid leukemia, in a dose- and time- dependent manner, which implied that ouabain increased cell sensitivity to imatinib. (ijpsonline.com)
  • These findings indicate ouabain probably has little inhibitory effect on the norepinephrine stimulation of N-acetyltransferase activity in the neonatal because a high affinity ouabain binding form of Na+,K+-ATPase activity, similar to the alpha + form identified in rat brain, is at very low levels in the pinealocyte. (nih.gov)
  • Unlike bufalin and ouabain, digoxin did not decrease JNK activation after long-term incubation. (scilifelab.se)
  • We have shown that the nanomolar concentrations of ouabain result in the temporary increase in the level of intracellular free radicals, but the millimolar concentration of ouabain induces a stable intracellular accumulation of free radicals in rat thymocytes. (nih.gov)
  • 14. Ouabain induces endocytosis of plasmalemmal Na/K-ATPase in LLC-PK1 cells by a clathrin-dependent mechanism. (nih.gov)
  • In addition, the relative orders of potency of four cardiac glycosides in displacing [3H]ouabain from high affinity binding sites and inhibiting both 86Rb uptake and NE stimulation of NAT activity were the same (acetyldigitoxin greater than ouabain greater than digitoxin greater than strophanthidin). (nih.gov)
  • Homogeneity or heterogeneity of rat soleus-muscle Na,K-ATPase (Na+ + K+-dependent ATPase) with respect to affinity for [3H]ouabain was evaluated. (regsj.dk)
  • Ouabain ( fig. 1a ) is a rapid-acting Cardiac Glycoside (CG) obtained from seeds of Strophanthus gratus [ 4 ]. (ijpsonline.com)
  • Cell Counting Kit-8 assay was used to detect cytotoxicity and reversal effect of ouabain with different concentration (0.01 μM, 0.1 μM, 1.0 μM, 10 μM) on drug resistance of imatinib-resistant cell line of chronic myeloid leukemia (K562/G01 cell line). (ijpsonline.com)
  • Ouabain increases intracellular Ca 2+ concentration by inhibiting Na + /K + ATPase, leading to the improvement of myocardial contractility. (ijpsonline.com)
  • Assuming homogeneity, the total concentration of [3H]ouabain binding sites in soleus-muscle samples from 12-week-old rats is 278-359 pmol/g wet wt. (regsj.dk)
  • The ouabain Kd value for the rat pineal binding sites was similar to the estimated ouabain IC50 values for 86Rb uptake and the NE stimulation of NAT activity in intact rat pinealocytes. (nih.gov)
  • Similarly, ouabain (1 nM to 1 mM) had no effect on 86Rb uptake in the 2-day-old gland but blocked (IC50 congruent to 20 nM) 86Rb uptake in the adult gland. (nih.gov)
  • However, measurements of [3H]ouabain uptake and retention over the range 0.1-5 mM, as well as the omission of wash-out, gave no evidence for heterogeneity of [3H]ouabain-binding sites in rat soleus muscle. (regsj.dk)
  • The Na + ,K + -ATPase, [ 3 H]ouabain binding, and proteins of mRNA A2 and B1 increased in VLM, whereas in PDM, only A2 protein increased as a result of training. (avma.org)
  • In the lab, we used the techniques of medicinal chemistry to create a derivative of ouabain that is good at zeroing in on the α4 transporter in sperm cells in rats. (thedailybeast.com)
  • At 7 d after ouabain treatment, 64 ± 24% less neuronal damage was observed in AEA-treated (10 mg/kg) rats compared with control animals. (tue.nl)
  • Carnosine prevents necrotic and apoptotic death of rat thymocytes via ouabain-sensitive Na/K-ATPase. (nih.gov)
  • 6. Expression of rat Na-K-ATPase α2 enables ion pumping but not ouabain-induced signaling in α1-deficient porcine renal epithelial cells. (nih.gov)
  • 13. Cell signaling associated with Na(+)/K(+)-ATPase: activation of phosphatidylinositide 3-kinase IA/Akt by ouabain is independent of Src. (nih.gov)
  • 18. Ammonia-induced Na,K-ATPase/ouabain-mediated EGF receptor transactivation, MAPK/ERK and PI3K/AKT signaling and ROS formation cause astrocyte swelling. (nih.gov)
  • The Na + ,K + -ATPase content, mRNA isoforms, and protein concentrations were determined by use of [ 3 H]ouabain binding, real-time PCR assay, and western blotting, respectively. (avma.org)
  • Ouabain inhibits (IC50 congruent to 200 nM) the congruent to 100-fold adrenergic cyclic AMP stimulation of rat pineal arylalkylamine N-acetyltransferase (EC, serotonin N-acetyltransferase, NAT) activity in intact pineal glands. (nih.gov)
  • it was found that K+ (80 microM) inhibited the adrenergic stimulation of N-acetyltransferase activity at all ages but that ouabain (1 nM to 1 mM) treatment was not inhibitory early in development. (nih.gov)
  • Ouabain has shown powerful anti-proliferation activities in various cancers, but its effect on imatinibresistant chronic myeloid leukemia and toxicity on normal mice has not been investigated. (ijpsonline.com)
  • The increasing level of free radicals resulting from both low and high concentrations of ouabain can be attenuated by the antioxidant, carnosine. (nih.gov)
  • But ouabain also affects another type of transporter subunit called α4, which is found only in sperm cells. (thedailybeast.com)
  • My colleagues and I are working on a promising lead for a male birth control pill based on ouabain -a plant extract that African warriors and hunters traditionally used as a heart-stopping poison on their arrows. (thedailybeast.com)
  • Hunters want ouabain to be deadly when used on an arrow, but no one wants a fatal contraceptive. (thedailybeast.com)
  • To obtain this poison, the African crested rat has been observed gnawing and chewing the bark of the Acokanthera to release ouabain, which is water soluble due to its hydroxyl groups. (spectroscopyeurope.com)
  • So we set out to design ouabain analogs-versions of the molecule that are more likely to bind to the α4 protein in sperm than other subunits in heart tissue. (thedailybeast.com)
  • Homogeneity of [3H]ouabain-binding sites in rat soleus muscle. (regsj.dk)
  • Udforsk hvilke forskningsemner 'Homogeneity of [3H]ouabain-binding sites in rat soleus muscle. (regsj.dk)
  • These data suggested that ouabain could be a potential agent to treat imatinib-resistant chronic myeloid leukemia for its powerful cytotoxicity as well as reversal effect, but further study is needed to find out its specific mechanism. (ijpsonline.com)
  • These data indicate that there was no endogenous endocannabinoid tone controlling the acute neuronal damage induced by ouabain. (tue.nl)
  • 1990. The interactions of ouabain with post-tetanic and facilitatory drug potentiations at cat soleus neuromuscular junctions in vivo. . (cornell.edu)
  • For 10 years, my colleagues and I have been studying ouabain as a potential breakthrough in our quest for a male birth control pill. (thedailybeast.com)
  • Mammals also produce ouabain in their bodies, though at lower nonlethal levels that scientists think can help control blood pressure. (thedailybeast.com)