Chloride Channels
Ion Channels
Calcium Channels
Ion Channel Gating
Cystic Fibrosis Transmembrane Conductance Regulator
Potassium Channels, Inwardly Rectifying
Calcium Channel Blockers
Potassium Channel Blockers
Myotonia Congenita
4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid
Electrophysiology
Membrane Potentials
Myotonia
Patch-Clamp Techniques
Niflumic Acid
Potassium Channels, Voltage-Gated
Calcium Channels, L-Type
Oocytes
KATP Channels
Xenopus laevis
Anions
Potassium Channels, Calcium-Activated
Xenopus
Molecular Sequence Data
Vinyl Chloride
Ion Transport
Shaker Superfamily of Potassium Channels
Sodium Channel Blockers
Amino Acid Sequence
Calcium Channels, N-Type
Ivermectin
Large-Conductance Calcium-Activated Potassium Channels
TRPC Cation Channels
Calcium Channels, T-Type
Hypotonic Solutions
Epithelial Sodium Channels
Cell Membrane
Potassium
Cyclic Nucleotide-Gated Cation Channels
Mutation
Calcium
Adenosine Triphosphate
Cystic Fibrosis
Acid Sensing Ion Channels
Cells, Cultured
Kv1.3 Potassium Channel
Ether-A-Go-Go Potassium Channels
Kv1.2 Potassium Channel
Kv1.1 Potassium Channel
Hydrogen-Ion Concentration
Polyvinyl Chloride
Membrane Proteins
Bartter Syndrome
TRPM Cation Channels
Calcium Channel Agonists
Kv1.5 Potassium Channel
Sodium
TRPV Cation Channels
Receptors, Glycine
Protein Structure, Tertiary
Dose-Response Relationship, Drug
KCNQ Potassium Channels
Shab Potassium Channels
Transfection
Rats, Sprague-Dawley
Neurons
Ions
Small-Conductance Calcium-Activated Potassium Channels
Barium
Scorpion Venoms
Cell Membrane Permeability
Kv1.4 Potassium Channel
Mercuric Chloride
Intermediate-Conductance Calcium-Activated Potassium Channels
Transient Receptor Potential Channels
Models, Biological
ortho-Aminobenzoates
Cricetinae
Shaw Potassium Channels
Receptors, GABA
Mutagenesis, Site-Directed
Binding Sites
Action Potentials
Cations
Kidney
Models, Molecular
Shal Potassium Channels
Protein Subunits
Cyclic AMP
4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid
CHO Cells
Lipid Bilayers
RNA, Messenger
HEK293 Cells
Calcium Chloride
Permeability
G Protein-Coupled Inwardly-Rectifying Potassium Channels
Chlorine
Potassium Chloride
Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels
KCNQ2 Potassium Channel
Structure-Activity Relationship
Epithelium
Sequence Homology, Amino Acid
Colforsin
DNA, Complementary
Mice, Inbred CFTR
Rabbits
Calcium Channels, P-Type
Methylene Chloride
Torpedo
Osmolar Concentration
Voltage-Dependent Anion Channels
RNA, Complementary
Ammonium Chloride
NAV1.5 Voltage-Gated Sodium Channel
Ligand-Gated Ion Channels
Ryanodine Receptor Calcium Release Channel
Rats, Wistar
Bufo bufo
KCNQ3 Potassium Channel
Cloning, Molecular
Epithelial Cells
Large-Conductance Calcium-Activated Potassium Channel alpha Subunits
Protein Conformation
Guinea Pigs
Strychnine
Anion Transport Proteins
Bromides
NAV1.2 Voltage-Gated Sodium Channel
Glycine
Trachea
Base Sequence
Delayed Rectifier Potassium Channels
Picrotoxin
Amiloride
Nephrocalcinosis
Calcium Channels, R-Type
Electrophysiological Phenomena
Protein Binding
Point Mutation
Cyclic AMP-Dependent Protein Kinases
Gene Expression
Myocardium
Antinematodal Agents
Sodium-Potassium-Chloride Symporters
Amino Acid Substitution
Benzalkonium Compounds
Channelopathies
Cadmium Chloride
Receptors, GABA-A
Charybdotoxin
Voltage-Gated Sodium Channels
Sulfonylurea Receptors
Muscle, Skeletal
Protein Structure, Secondary
Membrane Transport Modulators
Reverse Transcriptase Polymerase Chain Reaction
Glutamic Acid
Kidney Tubules, Collecting
Cattle
Protons
Nifedipine
Solute Carrier Family 12, Member 2
Dihydropyridines
Water-Electrolyte Balance
Cadmium
Blotting, Western
Mutation, Missense
Furosemide
Protein Isoforms
Receptors, Biogenic Amine
Relaxation of endothelin-1-induced pulmonary arterial constriction by niflumic acid and NPPB: mechanism(s) independent of chloride channel block. (1/2847)
We investigated the effects of the Cl- channel blockers niflumic acid, 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB) and 4, 4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) on endothelin-1 (ET-1)-induced constriction of rat small pulmonary arteries (diameter 100-400 microm) in vitro, following endothelium removal. ET-1 (30 nM) induced a sustained constriction of rat pulmonary arteries in physiological salt solution. Arteries preconstricted with ET-1 were relaxed by niflumic acid (IC50: 35.8 microM) and NPPB (IC50: 21.1 microM) in a reversible and concentration-dependent manner. However, at concentrations known to block Ca++-activated Cl- channels, DIDS (+info)Chloride dependence of hyperpolarization-activated chloride channel gates. (2/2847)
1. ClC proteins are a class of voltage-dependent Cl- channels with several members mutated in human diseases. The prototype ClC-0 Torpedo channel is a dimeric protein; each subunit forms a pore that can gate independently from the other one. A common slower gating mechanism acts on both pores simultaneously; slow gating activates ClC-0 at hyperpolarized voltages. The ClC-2 Cl- channel is also activated by hyperpolarization, as are some ClC-1 mutants (e.g. D136G) and wild-type (WT) ClC-1 at certain pH values. 2. We studied the dependence on internal Cl- ([Cl-]i) of the hyperpolarization-activated gates of several ClC channels (WT ClC-0, ClC-0 mutant P522G, ClC-1 mutant D136G and an N-terminal deletion mutant of ClC-2), by patch clamping channels expressed in Xenopus oocytes. 3. With all these channels, reducing [Cl-]i shifted activation to more negative voltages and reduced the maximal activation at most negative voltages. 4. We also investigated the external halide dependence of WT ClC-2 using two-electrode voltage-clamp recording. Reducing external Cl- ([Cl-]o) activated ClC-2 currents. Replacing [Cl-]o by the less permeant Br- reduced channel activity and accelerated deactivation. 5. Gating of the ClC-2 mutant K566Q in normal [Cl-]o resembled that of WT ClC-2 in low [Cl-]o, i.e. channels had a considerable open probability (Po) at resting membrane potential. Substituting external Cl- by Br- or I- led to a decrease in Po. 6. The [Cl-]i dependence of the hyperpolarization-activated gates of various ClC channels suggests a similar gating mechanism, and raises the possibility that the gating charge for the hyperpolarization-activated gate is provided by Cl-. 7. The external halide dependence of hyperpolarization-activated gating of ClC-2 suggests that it is mediated or modulated by anions as in other ClC channels. In contrast to the depolarization-activated fast gates of ClC-0 and ClC-1, the absence of Cl- favours channel opening. Lysine 556 may be important for the relevant binding site. (+info)Volume regulation following hypotonic shock in isolated crypts of mouse distal colon. (3/2847)
1. A video-imaging technique of morphometry was used to measure the diameter as an index of cell volume in intact mouse distal colon crypts submitted to hypotonic shock. 2. Transition from isotonic (310 mosmol l-1) to hypotonic (240 mosmol l-1) saline caused a pronounced increase in crypt diameter immediately followed by regulatory volume decrease (RVD). 3. Exposure of crypts to Cl--free hyposmotic medium increased the rapidity of both cell swelling and RVD. Exposure of crypts to Na+-free hyposmotic medium reduced the total duration of swelling. Return to initial diameter was followed by further shrinkage of the crypt cells. 4. The chloride channel inhibitor NPPB (50 microM) delayed the swelling phase and prevented the subsequent normal decrease in diameter. 5. The K+ channel blockers barium (10 mM), charybdotoxin (10 nM) and TEA (5 mM) inhibited RVD by 51, 44 and 32 %, respectively. 6. Intracellular [Ca2+] rose from a baseline of 174 +/- 17 nM (n = 8) to 448 +/- 45 nM (n = 8) during the initial swelling phase 7. The Ca2+ channel blockers verapamil (50 microM) and nifedipine (10 microM), the chelator of intracellular Ca2+ BAPTA AM (30 microM), or the inhibitor of Ca2+ release TMB-8 (10 microM), dramatically reduced volume recovery, leading to 51 % (n = 9), 25 % (n = 7), 37 % (n = 6), 32 % (n = 8) inhibition of RVD, respectively. TFP (50 microM), an antagonist of the Ca2+-calmodulin complex, significantly slowed RVD. The Ca2+ ionophore A23187 (2 microM) provoked a dramatic reduction of the duration and amplitude of cell swelling followed by extensive shrinkage. The release of Ca2+ from intracellular stores using bradykinin (1 microM) or blockade of reabsorption with thapsigargin (1 microM) decreased the duration of RVD. 8. Prostaglandin E2 (PGE2, 5 microM) slightly delayed RVD, whereas leukotriene D4 (LTD4, 100 nM) and arachidonic acid (10 microM) reduced the duration of RVD. Blockade of phospholipase A2 by quinacrine (10 microM) inhibited RVD by 53 %. Common inhibition of PGE2 and LTD4 synthesis by ETYA (50 microM) or separate blockade of PGE2 synthesis by 1 microM indomethacin reduced the duration of RVD. Blockade of LTD4 synthesis by nordihydroguaiaretic acid (NDGA) did not produce any significant effect on cell swelling or subsequent RVD. 9. Staurosporine (1 microM), an inhibitor of protein kinases, inhibited RVD by 58 %. Taken together the experiments demonstrate that the RVD process is under the control of conductive pathways, extra- and intracellular Ca2+ ions, protein kinases, prostaglandins and leukotrienes. (+info)Acetylcholine-induced membrane potential changes in endothelial cells of rabbit aortic valve. (4/2847)
1. Using a microelectrode technique, acetylcholine (ACh)-induced membrane potential changes were characterized using various types of inhibitors of K+ and Cl- channels in rabbit aortic valve endothelial cells (RAVEC). 2. ACh produced transient then sustained membrane hyperpolarizations. Withdrawal of ACh evoked a transient depolarization. 3. High K+ blocked and low K+ potentiated the two ACh-induced hyperpolarizations. Charybdotoxin (ChTX) attenuated the ACh-induced transient and sustained hyperpolarizations; apamin inhibited only the sustained hyperpolarization. In the combined presence of ChTX and apamin, ACh produced a depolarization. 4. In Ca2+-free solution or in the presence of Co2+ or Ni2+, ACh produced a transient hyperpolarization followed by a depolarization. In BAPTA-AM-treated cells, ACh produced only a depolarization. 5. A low concentration of A23187 attenuated the ACh-induced transient, but not the sustained, hyperpolarization. In the presence of cyclopiazonic acid, the hyperpolarization induced by ACh was maintained after ACh removal; this maintained hyperpolarization was blocked by Co2+. 6. Both NPPB and hypertonic solution inhibited the membrane depolarization seen after ACh washout. Bumetanide also attenuated this depolarization. 7. It is concluded that in RAVEC, ACh produces a two-component hyperpolarization followed by a depolarization. It is suggested that ACh-induced Ca2+ release from the storage sites causes a transient hyperpolarization due to activation of ChTX-sensitive K+ channels and that ACh-activated Ca2+ influx causes a sustained hyperpolarization by activating both ChTX- and apamin-sensitive K+ channels. Both volume-sensitive Cl- channels and the Na+-K+-Cl- cotransporter probably contribute to the ACh-induced depolarization. (+info)ATP dependence of the ICl,swell channel varies with rate of cell swelling. Evidence for two modes of channel activation. (5/2847)
Swelling-induced activation of the outwardly rectifying anion current, ICl, swell, is modulated by intracellular ATP. The mechanisms by which ATP controls channel activation, however, are unknown. Whole cell patch clamp was employed to begin addressing this issue. Endogenous ATP production was inhibited by dialyzing N1E115 neuroblastoma cells for 4-5 min with solutions containing (microM): 40 oligomycin, 5 iodoacetate, and 20 rotenone. The effect of ATP on current activation was observed in the absence of intracellular Mg2+, in cells exposed to extracellular metabolic inhibitors for 25-35 min followed by intracellular dialysis with oligomycin, iodoacetate, and rotenone, after substitution of ATP with the nonhydrolyzable analogue AMP-PNP, and in the presence of AMP-PNP and alkaline phosphatase to dephosphorylate intracellular proteins. These results demonstrate that the ATP dependence of the channel requires ATP binding rather than hydrolysis and/or phosphorylation reactions. When cells were swollen at 15-55%/min in the absence of intracellular ATP, current activation was slow (0.3-0.8 pA/pF per min). ATP concentration increased the rate of current activation up to maximal values of 4-6 pA/pF per min, but had no effect on the sensitivity of the channel to cell swelling. Rate of current activation was a saturable, hyperbolic function of ATP concentration. The EC50 for ATP varied inversely with the rate of cell swelling. Activation of current was rapid (4-6 pA/pF per min) in the absence of ATP when cells were swollen at rates >/=65%/min. Intracellular ATP concentration had no effect on current activation induced by high rates of swelling. Current activation was transient when endogenous ATP was dialyzed out of the cytoplasm of cells swollen at 15%/min. Rundown of the current was reversed by increasing the rate of swelling to 65%/min. These results indicate that the channel and/or associated regulatory proteins are capable of sensing the rate of cell volume increase. We suggest that channel activation occurs via ATP-dependent and -independent mechanisms. Increasing the rate of cell swelling appears to increase the proportion of channels activating via the ATP-independent pathway. These findings have important physiological implications for understanding ICl, swell regulation, the mechanisms by which cells sense volume changes, and volume homeostasis under conditions where cell metabolism is compromised. (+info)The muscle chloride channel ClC-1 has a double-barreled appearance that is differentially affected in dominant and recessive myotonia. (6/2847)
Single-channel recordings of the currents mediated by the muscle Cl- channel, ClC-1, expressed in Xenopus oocytes, provide the first direct evidence that this channel has two equidistant open conductance levels like the Torpedo ClC-0 prototype. As for the case of ClC-0, the probabilities and dwell times of the closed and conducting states are consistent with the presence of two independently gated pathways with approximately 1.2 pS conductance enabled in parallel via a common gate. However, the voltage dependence of the common gate is different and the kinetics are much faster than for ClC-0. Estimates of single-channel parameters from the analysis of macroscopic current fluctuations agree with those from single-channel recordings. Fluctuation analysis was used to characterize changes in the apparent double-gate behavior of the ClC-1 mutations I290M and I556N causing, respectively, a dominant and a recessive form of myotonia. We find that both mutations reduce about equally the open probability of single protopores and that mutation I290M yields a stronger reduction of the common gate open probability than mutation I556N. Our results suggest that the mammalian ClC-homologues have the same structure and mechanism proposed for the Torpedo channel ClC-0. Differential effects on the two gates that appear to modulate the activation of ClC-1 channels may be important determinants for the different patterns of inheritance of dominant and recessive ClC-1 mutations. (+info)A single hydrophobic residue confers barbiturate sensitivity to gamma-aminobutyric acid type C receptor. (7/2847)
Barbiturate sensitivity was imparted to the human rho1 homooligomeric gamma-aminobutyric acid (GABA) receptor channel by mutation of a tryptophan residue at position 328 (Trp328), which is located within the third transmembrane domain. Substitutions of Trp328 with a spectrum of amino acids revealed that nearly all hydrophobic residues produced receptor channels that were both directly activated and modulated by pentobarbital with similar sensitivities. Previous studies with ligand-gated ion channels (including GABA) have demonstrated that even conservative amino acid substitution within the agonist-dependent activation domain (N-terminal extracellular domain) can markedly impair agonist sensitivity. Thus, the lack of significant variation in pentobarbital sensitivity among the Trp328 mutants attests to an intrinsic difference between pentobarbital- and the GABA-dependent activation domain. Compared with the heterooligomeric alphabetagamma receptor channel, the mode of modulation for homooligomeric Trp328 mutants by pentobarbital was more dependent on the GABA concentration, yielding potentiation only at low concentrations of GABA (fractions of their respective EC50 values), yet causing inhibition at higher concentrations. Agonist-related studies have also demonstrated that residue 328 plays an important role in agonist-dependent activation, suggesting a functional interconnection between the GABA and pentobarbital activation domains. (+info)Functional and molecular characterization of a volume-sensitive chloride current in rat brain endothelial cells. (8/2847)
1. Volume-activated chloride currents in cultured rat brain endothelial cells were investigated on a functional level using the whole-cell voltage-clamp technique and on a molecular level using the reverse transcriptase-polymerase chain reaction (RT-PCR). 2. Exposure to a hypotonic solution caused the activation of a large, outward rectifying current, which exhibited a slight time-dependent decrease at strong depolarizing potentials. The anion permeability of the induced current was I- (1.7) > Br- (1.2) > Cl- (1.0) > F- (0. 7) > gluconate (0.18). 3. The chloride channel blocker 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB, 100 microM) rapidly and reversibly inhibited both inward and outward currents. The chloride transport blocker 4,4'-diisothiocyanatostilbene-2, 2'-disulphonic acid (DIDS, 100 microM) also blocked the hypotonicity-induced current in a reversible manner. In this case, the outward current was more effectively suppressed than the inward current. The volume-activated current was also inhibited by the antioestrogen tamoxifen (10 microM). 4. The current was dependent on intracellular ATP and independent of intracellular Ca2+. 5. Activation of protein kinase C by phorbol 12,13-dibutyrate (PDBu, 100 nM) inhibited the increase in current normally observed following hypotonic challenge. 6. Extracellular ATP (10 mM) inhibited the current with a more pronounced effect on the outward than the inward current. 7. Verapamil (100 microM) decreased both the inward and the outward hypotonicity-activated chloride current. 8. RT-PCR analysis was used to determine possible molecular candidates for the volume-sensitive current. Expression of the ClC-2, ClC-3 and ClC-5 chloride channels, as well as pICln, could be shown at the mRNA level. 9. We conclude that rat brain endothelial cells express chloride channels which are activated by osmotic swelling. The biophysical and pharmacological properties of the current show strong similarities to those of ClC-3 channel currents as described in other cell types. (+info)The symptoms of myotonia congenita can vary in severity and may include:
* Muscle stiffness and rigidity, especially in the legs, arms, and neck
* Difficulty relaxing muscles after contraction, leading to prolonged muscle tensing
* Muscle cramps and spasms
* Weakness and fatigue of the muscles
* Delayed or absent deep tendon reflexes
* Abnormal posture or gait
* Difficulty with speech and swallowing in severe cases
Myotonia congenita can be diagnosed through a combination of clinical evaluation, electromyography (EMG), and genetic testing. Treatment for the condition typically involves physical therapy, massage, and relaxation techniques to help manage muscle stiffness and improve mobility. In severe cases, medications such as sodium channel blockers or chloride channel activators may be prescribed to help regulate muscle contraction and relaxation.
Myotonia congenita is a rare condition, and its prevalence is not well established. However, it is estimated to affect approximately 1 in 100,000 to 1 in 200,000 individuals worldwide. The condition can be inherited in an autosomal dominant manner, meaning that a single copy of the mutated gene is enough to cause the condition. However, some cases may be sporadic, meaning they are not inherited from either parent.
Overall, myotonia congenita is a rare and complex genetic disorder that affects the muscles and can significantly impact an individual's quality of life. With proper diagnosis and management, individuals with myotonia congenita can lead fulfilling lives despite the challenges posed by the condition.
There are two main types of myotonia:
1. Thomsen's disease: This is an inherited form of myotonia that affects the muscles of the face, neck, and limbs. It is caused by mutations in the CLCN1 gene and can be severe, causing difficulty with speaking, swallowing, and breathing.
2. Becker's muscular dystrophy: This is a form of muscular dystrophy that affects both the skeletal and cardiac muscles. It is caused by mutations in the DMPK gene and can cause myotonia, muscle weakness, and heart problems.
The symptoms of myotonia can vary depending on the severity of the condition and may include:
* Muscle stiffness and rigidity
* Spasms or twitches
* Difficulty with movement and mobility
* Fatigue and weakness
* Cramps
* Muscle wasting
Myotonia can be diagnosed through a combination of physical examination, medical history, and diagnostic tests such as electromyography (EMG) and muscle biopsy. There is no cure for myotonia, but treatment options may include:
* Physical therapy to improve movement and mobility
* Medications to relax muscles and reduce spasms
* Lifestyle modifications such as avoiding triggers and taking regular breaks to rest
* Surgery in severe cases to release or lengthen affected muscles.
It is important to note that myotonia can be a symptom of other underlying conditions, so proper diagnosis and management by a healthcare professional is essential to determine the best course of treatment.
Symptoms of cystic fibrosis can vary from person to person, but may include:
* Persistent coughing and wheezing
* Thick, sticky mucus that clogs airways and can lead to respiratory infections
* Difficulty gaining weight or growing at the expected rate
* Intestinal blockages or digestive problems
* Fatty stools
* Nausea and vomiting
* Diarrhea
* Rectal prolapse
* Increased risk of liver disease and respiratory failure
Cystic fibrosis is usually diagnosed in infancy, and treatment typically includes a combination of medications, respiratory therapy, and other supportive care. Management of the disease focuses on controlling symptoms, preventing complications, and improving quality of life. With proper treatment and care, many people with cystic fibrosis can lead long, fulfilling lives.
In summary, cystic fibrosis is a genetic disorder that affects the respiratory, digestive, and reproductive systems, causing thick and sticky mucus to build up in these organs, leading to serious health problems. It can be diagnosed in infancy and managed with a combination of medications, respiratory therapy, and other supportive care.
The main symptoms of Bartter Syndrome are:
* Low potassium levels (hypokalemia)
* High aldosterone levels (hyperaldosteronism)
* Normal blood pressure
* Increased urine production (polyuria)
* Dehydration
* Fatigue
Bartter Syndrome can be diagnosed with a combination of clinical evaluation, laboratory tests, and genetic analysis. Treatment for the condition typically involves potassium supplements, dietary restrictions, and medications to control blood pressure and electrolyte levels. In severe cases, dialysis may be required.
The prognosis for Bartter Syndrome is generally good if the condition is properly managed. However, in some cases, the syndrome can progress to more severe forms of kidney disease, such as end-stage renal disease. With proper treatment and management, many individuals with Bartter Syndrome are able to lead normal lives and avoid complications.
Symptoms of nephrocalcinosis may include nausea, vomiting, abdominal pain, frequent urination, and blood in the urine. Diagnosis is typically made through imaging tests such as X-rays, CT scans, or ultrasound, and blood tests to determine calcium levels and kidney function.
Treatment for nephrocalcinosis depends on the underlying cause of the condition and may include medications to lower calcium levels, dietary changes to reduce calcium intake, and in severe cases, dialysis or kidney transplantation may be necessary. It is important to seek medical attention if symptoms persist or worsen over time, as early detection and treatment can help prevent long-term damage to the kidneys.
There are several types of channelopathies, including:
1. Long QT syndrome: This is a condition that affects the ion channels in the heart, leading to abnormal heart rhythms and increased risk of sudden death.
2. Short QT syndrome: This is a rare condition that has the opposite effect of long QT syndrome, causing the heart to beat too quickly.
3. Catecholaminergic polymorphic ventricular tachycardia (CPVT): This is a rare disorder that affects the ion channels in the heart, leading to abnormal heart rhythms and increased risk of sudden death.
4. Brugada syndrome: This is a condition that affects the ion channels in the heart, leading to abnormal heart rhythms and increased risk of sudden death.
5. Wolff-Parkinson-White (WPW) syndrome: This is a condition that affects the ion channels in the heart, leading to abnormal heart rhythms and increased risk of sudden death.
6. Neuromuscular disorders: These are disorders that affect the nerve-muscle junction, leading to muscle weakness and wasting. Examples include muscular dystrophy and myasthenia gravis.
7. Dystrophinopathies: These are a group of disorders that affect the structure of muscle cells, leading to muscle weakness and wasting. Examples include Duchenne muscular dystrophy and Becker muscular dystrophy.
8. Myotonia: This is a condition that affects the muscles, causing them to become stiff and rigid.
9. Hyperkalemic periodic paralysis: This is a rare condition that causes muscle weakness and paralysis due to abnormal potassium levels in the body.
10. Hypokalemic periodic paralysis: This is a rare condition that causes muscle weakness and paralysis due to low potassium levels in the body.
11. Thyrotoxic periodic paralysis: This is a rare condition that causes muscle weakness and paralysis due to an overactive thyroid gland.
12. Hyperthyroidism: This is a condition where the thyroid gland becomes overactive, leading to increased heart rate, weight loss, and muscle weakness.
13. Hypothyroidism: This is a condition where the thyroid gland becomes underactive, leading to fatigue, weight gain, and muscle weakness.
14. Pituitary tumors: These are tumors that affect the pituitary gland, which regulates hormone production in the body.
15. Adrenal tumors: These are tumors that affect the adrenal glands, which produce hormones such as cortisol and aldosterone.
16. Carcinoid syndrome: This is a condition where cancer cells in the digestive system produce hormones that can cause muscle weakness and wasting.
17. Multiple endocrine neoplasia (MEN): This is a genetic disorder that affects the endocrine system and can cause tumors to grow in the thyroid, adrenal, and parathyroid glands.
These are just some of the many potential causes of muscle weakness. It's important to see a healthcare professional for an accurate diagnosis and appropriate treatment.
There are several types of kidney calculi, including:
1. Calcium oxalate calculi: These are the most common type of calculus and are often associated with conditions such as hyperparathyroidism or excessive intake of calcium supplements.
2. Uric acid calculi: These are more common in people with gout or a diet high in meat and sugar.
3. Cystine calculi: These are rare and usually associated with a genetic disorder called cystinuria.
4. Struvite calculi: These are often seen in women with urinary tract infections (UTIs).
Symptoms of kidney calculi may include:
1. Flank pain (pain in the side or back)
2. Pain while urinating
3. Blood in the urine
4. Cloudy or strong-smelling urine
5. Fever and chills
6. Nausea and vomiting
Kidney calculi are diagnosed through a combination of physical examination, medical history, and diagnostic tests such as X-rays, CT scans, or ultrasound. Treatment options for kidney calculi depend on the size and location of the calculus, as well as the severity of any underlying conditions. Small calculi may be treated with conservative measures such as fluid intake and medication to help flush out the crystals, while larger calculi may require surgical intervention to remove them.
Preventive measures for kidney calculi include staying hydrated to help flush out excess minerals in the urine, maintaining a balanced diet low in oxalate and animal protein, and avoiding certain medications that can increase the risk of calculus formation. Early detection and treatment of underlying conditions such as hyperparathyroidism or gout can also help prevent the development of kidney calculi.
Overall, kidney calculi are a common condition that can be managed with proper diagnosis and treatment. However, they can cause significant discomfort and potentially lead to complications if left untreated, so it is important to seek medical attention if symptoms persist or worsen over time.
Examples of inborn errors of renal tubular transport include:
1. Cystinuria: This is a disorder that affects the reabsorption of cystine, an amino acid, in the renal tubules. It can lead to the formation of cystine stones in the kidneys.
2. Lowe syndrome: This is a rare genetic disorder that affects the transport of sodium and potassium ions across the renal tubules. It can cause a range of symptoms, including delayed development, intellectual disability, and seizures.
3. Glycine encephalopathy: This is a rare genetic disorder that affects the transport of glycine, an amino acid, across the renal tubules. It can cause a range of symptoms, including muscle weakness, developmental delays, and seizures.
4. Hartnup disease: This is a rare genetic disorder that affects the transport of tryptophan, an amino acid, across the renal tubules. It can cause a range of symptoms, including diarrhea, weight loss, and skin lesions.
5. Maple syrup urine disease: This is a rare genetic disorder that affects the transport of branched-chain amino acids (leucine, isoleucine, and valine) across the renal tubules. It can cause a range of symptoms, including seizures, developmental delays, and kidney damage.
Inborn errors of renal tubular transport can be diagnosed through a combination of clinical evaluation, laboratory tests, and genetic analysis. Treatment depends on the specific disorder and may include dietary modifications, medications, and dialysis. Early detection and treatment can help manage symptoms and prevent complications.
The word "osteopetrosis" comes from the Greek words "osteon," meaning bone, and "petros," meaning rock or stone. This name reflects the dense and hard nature of the bones affected by the disorder.
Osteopetrosis can be caused by mutations in several genes that are involved in bone development and growth. The condition is usually inherited in an autosomal dominant pattern, meaning that a single copy of the mutated gene is enough to cause the disorder. However, some cases may be caused by spontaneous mutations or other factors.
Symptoms of osteopetrosis can vary depending on the severity of the disorder and the specific affected bones. Common symptoms include bone pain, limited mobility, and an increased risk of fractures. Other symptoms may include fatigue, fever, and difficulty swallowing or breathing.
Treatment for osteopetrosis usually involves a combination of medications and surgery. Medications such as bisphosphonates and denintuzumab mafodotin can help reduce bone pain and the risk of fractures, while surgery may be necessary to correct deformities or repair broken bones. In some cases, bone marrow transplantation may be recommended to replace damaged bone marrow with healthy cells.
Overall, osteopetrosis is a rare and debilitating disorder that can have a significant impact on quality of life. Early diagnosis and appropriate treatment are important for managing symptoms and preventing complications.
There are two main types of myotonic dystrophy:
1. Type 1 (also known as DM1): This is the most common form of the disorder and affects about 90% of all cases. It is caused by a mutation in the DMPK gene on chromosome 19.
2. Type 2 (also known as DM2): This form of the disorder is less common and affects about 10% of all cases. It is caused by a mutation in the CNBP gene on chromosome 3.
Symptoms of myotonic dystrophy typically appear in adults between the ages of 20 and 40, but can sometimes be present at birth. They may include:
* Muscle stiffness and rigidity
* Weakness of the face, neck, and limbs
* Difficulty swallowing (dysphagia)
* Difficulty speaking or slurred speech (dysarthria)
* Eye problems, such as cataracts or muscle imbalance in the eyelids
* Cramps and muscle spasms
* Fatigue and weakness
* Slowed muscle relaxation after contraction (myotonia)
Myotonic dystrophy is diagnosed through a combination of physical examination, medical history, and genetic testing. There is currently no cure for the disorder, but various treatments can help manage symptoms and slow its progression. These may include:
* Physical therapy to improve muscle strength and function
* Medications to relax muscles and reduce spasms
* Speech therapy to improve communication and swallowing difficulties
* Occupational therapy to assist with daily activities and independence
* Orthotics and assistive devices to help with mobility and other challenges
It is important for individuals with myotonic dystrophy to work closely with their healthcare providers to manage their symptoms and maintain a good quality of life. With appropriate treatment and support, many people with the disorder are able to lead active and fulfilling lives.
Chloride channel
Chloride channel opener
Chloride channel blocker
Calcium-dependent chloride channel
Chloride
Glutamate (neurotransmitter)
Avermectin
Ionic Coulomb blockade
Ion channel
CLCNKB
CLCN7
CLCN4
Channel blocker
CLIC3
CLCN6
CLCN3
CLCNKA
Tetratricopeptide repeat protein 39B
CLIC2
Pyriprole
CLIC6
CLIC1
CLIC5
Human uses of scorpions
Potassium channel
CLIC4
Cystic fibrosis transmembrane conductance regulator
Myotonic dystrophy
CLCN5
TRAPPC2
Gamma-aminobutyric acid receptor subunit gamma-2
Halobacterium salinarum
Metabolism
Quazepam
Voltage-gated ion channel
Pre-Bötzinger complex
GABRA4
Basal electrical rhythm
Olfactory receptor neuron
New car smell
The Little Guy
Lake Zabuye
GABAA receptor positive allosteric modulator
Sonogashira coupling
WNK1
WNK3
Pi-interaction
Isotopes of rutherfordium
Loop diuretic
Index of biochemistry articles
Rouge National Urban Park
Vastitas Borealis
Polystyrene
Alcohol myopia
Brain-computer interface
Oh Uhtaek
Practices of Apple Inc.
Norepinephrine transporter
Medical Science Monitor | Calcium-Activated Chloride Channel A4 (CLCA4) Plays Inhibitory Roles in Invasion and Migration...
4-(Furan-2'-yl)-1,4-dihydropyridine derivatives potentiate the CFTR chloride channel
Development of Automated Patch Clamp Technique to Investigate CFTR Chloride Channel Function - Sophion
A Study of VX-445 Combination Therapy in CF Subjects Homozygous for F508del (F/F) - Full Text View - ClinicalTrials.gov
Slimy partners: the mucus barrier and gut microbiome in ulcerative colitis | Experimental & Molecular Medicine
Endophilin A2 regulates calcium-activated chloride channel activity via selective autophagy-mediated TMEM16A degradation. |...
Human CLCA2 (NP 006527) VersaClone cDNA RDC1233: R&D Systems
MMRRC:038846-MU
Clic6 | Knockout Mouse | Research Models | Taconic Biosciences
Irritable Bowel Syndrome (IBS): Practice Essentials, Background, Pathophysiology
Chemistry | UCD Research.
CLCN7 gene: MedlinePlus Genetics
Sucampo Reports Strong Results for First Quarter of 2016
NIOSHTIC-2 Search Results - Full View
Jedarna membrana - Wikipedia
WikiGenes
Newborn Screening for Cystic Fibrosis: A Paradigm for Public
Health Genetics Policy Development Proceedings of a 1997 Workshop
Epilepsy and Seizures: Practice Essentials, Background, Pathophysiology
Frontiers | Differentiated mouse kidney tubuloids as a novel in vitro model to study collecting duct physiology
Isabelle MARTINS | PhD | French Institute of Health and Medical Research | Inserm | Research profile
JCI Insight -
Residual function of cystic fibrosis mutants predicts response to small molecule CFTR modulators
Function and dysfunction of the colon and anorectum in adults: Working team report of the Swedish Motility Group (SMoG) | Lund...
Biomedicines | Free Full-Text | The Mito-Hormetic Mechanisms of Ozone in the Clearance of SARS-CoV2 and in the COVID-19 Therapy
Cydectin® Sheep Drench - Premier1Supplies
The Journal of Physiology | Scholars@Duke
Ions12
- Negatively charged chloride can cross biological membranes only with the help of membrane-spanning proteins such as Cl - channels, which allow passive diffusion of Cl - along its electrochemical gradient, or transporter proteins that couple the movement of Cl - to that of other ions and can thereby establish electrochemical gradients. (elifesciences.org)
- CLCA1 was labeled a chloride channel because it appeared to be moving chloride ions across the cell membrane. (genengnews.com)
- The ClC-Ka and ClC-Kb channels transport charged atoms of chlorine (chloride ions) out of kidney cells. (medlineplus.gov)
- The transport of chloride ions is part of the mechanism by which the kidneys reabsorb salt (sodium chloride or NaCl) from the urine back into the bloodstream. (medlineplus.gov)
- Other mutations allow the channels to reach the cell membrane but prevent them from transporting ions properly. (medlineplus.gov)
- The channel transports negatively charged particles called chloride ions into and out of cells. (nih.gov)
- The transport of chloride ions helps control the movement of water in tissues, which is necessary for the production of thin, freely flowing mucus. (nih.gov)
- The CFTR protein also regulates the function of other channels, such as those that transport positively charged particles called sodium ions across cell membranes. (nih.gov)
- Mutations in the CFTR gene disrupt the function of the chloride channel, preventing the usual flow of chloride ions and water into and out of cells. (nih.gov)
- The resulting abnormal channel breaks down shortly after it is made, so it never reaches the cell membrane to transport chloride ions. (nih.gov)
- All of these changes prevent the channel from functioning properly, which impairs the transport of chloride ions and the movement of water into and out of cells. (nih.gov)
- Cell membrane glycoproteins that form channels to selectively pass chloride ions. (nih.gov)
Cystic fibrosis1
- The chloride (Cl - ) channel cystic fibrosis transmembrane conductance regulator (CFTR) is defective in cystic fibrosis (CF), and mutation of its encoding gene leads to various defects such as retention of the misfolded protein in the endoplasmic reticulum, reduced stability at the plasma membrane, abnormal channel gating with low open probability, and thermal instability, which leads to inactivation of the channel at physiological temperature. (sophion.com)
Intracellular1
- 3. The intracellular chloride channel 4 (CLIC4) activates systemic sclerosis fibroblasts. (nih.gov)
Activator1
- Cobiprostone is a locally acting chloride channel activator that works to stimulate and protect the mucosal barrier function. (nursingcenter.com)
CaCC1
- TMEM16A Ca2+-activated chloride channel ( CaCC ) plays an essential role in vascular homeostasis . (bvsalud.org)
CFTR4
- For instance, deletion of phenylalanine at position 508 (DF508), the most frequent mutation (occurring in more than 50-70 % of patients), causes both a severe defect of CFTR protein processing (trafficking defect) and a decrease of its channel activity (gating defect). (units.it)
- It has been shown that mutant CFTR is activated by DHPs through a mechanism not involving the modulation of Ca++ channels, but the direct interaction with the CFTR protein itself. (units.it)
- Studies of Molecular Modeling on DHPs are in progress: our preliminary data show that DHPs lay into a channel near to the ATP pocket in NBD1 of CFTR (Figure 2): the presence of Potentiators in this site could make more difficult the hydrolysis of ATP, having as a consequence a longer opening time of the CFTR channel. (units.it)
- Disease-causing mutations in the CFTR gene alter the production, structure, or stability of the chloride channel. (nih.gov)
Gene6
- This protein is found primarily in the kidneys, where it attaches (binds) to two specific chloride channels: ClC-Ka (produced from the CLCNKA gene) and ClC-Kb (produced from the CLCNKB gene). (medlineplus.gov)
- BSND gene mutations impair barttin's ability to regulate the ClC-Ka and ClC-Kb channels. (medlineplus.gov)
- Analysis of lung gene expression reveals a role for Cl- channels in diisocyanate induced airway eosinophilia in a mouse model of asthma pathology. (cdc.gov)
- CLCA1 (calcium-activated chloride channel regulator 1) was the most upregulated gene transcript (>100-fold) in all exposed mouse lungs versus controls, followed closely by SLC26A4, another transcript involved in Cl- conductance. (cdc.gov)
- Crofelemer, a U.S. Food and Drug Administration-approved Cl- channel inhibitor, reduced MDI exposure induction of airway eosinophilia, mucus, CLCA1, and other asthma-associated gene transcripts. (cdc.gov)
- When the report concerning chloride impermeability was published, efforts to find the gene were already well under way, terminating with a triumphant application of the techniques of reverse genetics. (rtmagazine.com)
Regulates2
- Endophilin A2 regulates calcium-activated chloride channel activity via selective autophagy-mediated TMEM16A degradation. (bvsalud.org)
- It also regulates the channels' stability and function. (medlineplus.gov)
Potassium1
- Considering the molecular weight-function relationship of previously identified venom peptides, future bioactivity studies may lead to the discovery of novel potassium and chloride ion channel inhibitors as well as new antimicrobial peptides from L. abdullahbayrami venom. (scielo.br)
Epithelial1
- In 1983, Quinton and Bijman 4 clearly demonstrated the characteristic cellular defect of CF, which is epithelial chloride impermeability. (rtmagazine.com)
Lubiprostone1
- Evolving drugs include lubiprostone, which enhances colonic secretion by activating chloride channels. (lu.se)
CLCA17
- The new study lays the groundwork for developing treatments for diseases such as asthma, COPD, cystic fibrosis, and even certain cancers," notes senior author Thomas J. Brett, Ph.D., assistant professor of medicine, and whose team's research report ("Secreted CLCA1 modulates TMEM16A to activate Ca 2+ -dependent chloride currents in human cells") appears in eLife. (genengnews.com)
- Studies at the time suggested CLCA1 was an ion channel, a small opening in the cell membrane that allows charged particles to flow into or out of the cell. (genengnews.com)
- Originally, CLCA1 was misidentified as a chloride channel," continues Dr. Brett. (genengnews.com)
- When cells express CLCA1, they produce chloride currents. (genengnews.com)
- Our results identify the first Cl− channel target of the CLCA family of proteins and establish CLCA1 as the first secreted direct modifier of TMEM16A activity, delineating a unique mechanism to increase currents," wrote the investigators. (genengnews.com)
- We don't think that CLCA1 actually opens the channel," explains Dr. Brett. (genengnews.com)
- In fact, the channel can function without CLCA1. (genengnews.com)
Protein6
- Mechanistically, ANO1 knockdown or pharmacological inhibition of its chloride-channel activity reduced EGF receptor (EGFR) and calmodulin-dependent protein kinase II (CAMKII) signaling, which subsequently attenuated AKT, v-src sarcoma viral oncogene homolog (SRC), and extracellular signal-regulated kinase (ERK) activation in vitro and in vivo. (nih.gov)
- Only seven years ago, a protein that proved to be this elusive type of channel was first discovered in mammals. (genengnews.com)
- We don't know of any other examples of this type of interaction between a protein and a channel. (genengnews.com)
- According to Dr. Brett, his team is continuing to study these interactions to learn more about how increasing or decreasing expression of the protein or the channel may influence the currents, and what impact that may have in airway diseases. (genengnews.com)
- This protein functions as a channel across the membrane of cells that produce mucus, sweat, saliva, tears, and digestive enzymes. (nih.gov)
- In this study, we further characterized mouse tubuloids and differentiated them towards the collecting duct, which led to a significant upregulation of collecting duct-specific mRNAs of genes and protein expression, including the water channel AQP2 and the sodium channel ENaC. (frontiersin.org)
Tumor2
- Calcium-activated chloride channel A4 (CLCA4) is known as a tumor suppressor which contributes to the progression of a number of types of malignant tumors. (medscimonit.com)
- Our results highlight the involvement of the ANO1 chloride channel in tumor progression and provide insights into oncogenic signaling in human cancers with 11q13 amplification, thereby establishing ANO1 as a promising target for therapy in these highly prevalent tumor types. (nih.gov)
Calcium6
- Calcium-activated chloride channel ANO1 promotes breast cancer progression by activating EGFR and CAMK signaling. (nih.gov)
- The calcium-activated chloride channel anoctamin 1 (ANO1) is located within the 11q13 amplicon, one of the most frequently amplified chromosomal regions in human cancer, but its functional role in tumorigenesis has remained unclear. (nih.gov)
- In this study, the effects of calcium channel antagonists on the antidepressant action of alprazolam and imipramine were investigated. (who.int)
- four groups each received a single dose of the calcium channel blocker followed by a single dose of the antidepressant (with same doses used for either in the previous four groups). (who.int)
- This may be due to the fact that nifedipine on its own might act as an antidepressant but blocks one imipramine mechanism that depends on L-type calcium channel activation. (who.int)
- The mouse FST for mental depression to investigate the effect of model has been widely used in screening the calcium channel blockers, nifedipine and antidepressants because it is simple and has been verapamil, on the antidepressant action of reported to be reliable across laboratories. (who.int)
Anion channel2
- We now used a genome-wide siRNA screen to molecularly identify the widely expressed acid-sensitive outwardly-rectifying anion channel PAORAC/ASOR. (elifesciences.org)
- Molecular relation between anion channel and transporter: Evolutional insight of anion channel/transporter molecules. (nips.ac.jp)
Genetic1
- On the flip side, these channel currents may be able to compensate for the genetic defect in cystic fibrosis, which causes mucus that is too thick and sticky. (genengnews.com)
Mutations1
- Some mutations keep the channels from ever reaching the cell membrane. (medlineplus.gov)
TMEM16A1
- Called TMEM16A, it is a channel that is ubiquitous in the cells lining the airway. (genengnews.com)
Antagonists1
- Based on therapeutic option, the global constipation treatment market has been segmented into laxatives, chloride channel activators, peripherally acting mu opioid receptor antagonists, GC-C agonists and 5-HT4 receptor agonists. (clickpress.com)
Proteins4
- Elucidation of these roles has been greatly facilitated by the molecular identification of the underlying channel proteins, a discovery process that began in the late 1980's and is still ongoing. (elifesciences.org)
- But as we became better at understanding the three-dimensional structures of proteins, researchers in the field started to realize that CLCA proteins couldn't be channels. (genengnews.com)
- For example, TMEM16 channels and CLCA proteins have been associated with certain types of cancers, including breast tumors that spread to the lungs and in some cardiovascular disorders such as irregular heart rhythms and heart failure, demonstrating a possible broad impact of future work in this area. (genengnews.com)
- Scorpion venoms are composed of inorganic salts, free amino acids, nucleotides, biogenic amines, peptides and proteins [ 4 Quintero-Hernández V, Jiménez-Vargas JM, Gurrola GB, Valdivia HH, Possani LD: Scorpion venom components that affect ion-channels function.Toxicon 2013,76:328-342. (scielo.br)
Decrease1
- It is transmission of dopamine or NA decrease a highly specific antagonist of the L-type channel immobility, whereas agents having the opposite blocks [5]. (who.int)
Cell2
- Moreover, ANO1 chloride channel activity was important for cell viability. (nih.gov)
- Barttin is essential for the normal placement of ClC-Ka and ClC-Kb channels in the cell membrane. (medlineplus.gov)
Currents1
- So the question arose, how do they activate these currents if they're not channels? (genengnews.com)
Pathology2
- Acid-sensing ion channels have important functions in physiology and pathology, but the molecular composition of acid-activated chloride channels had remained unclear. (elifesciences.org)
- In addition to chemokines and alternatively activated monocytes/macrophages, the data suggest a crucial role for Cl- channels in diisocyanate asthma pathology and as a possible target for intervention. (cdc.gov)
Kidney1
- Kramer BK, Bergler T, Stoelcker B, Waldegger S. Mechanisms of Disease: the kidney-specific chloride channels ClCKA and ClCKB, the Barttin subunit, and their clinical relevance. (medlineplus.gov)
Constipation1
- Based on the distribution channel, the global constipation treatment market is segmented into hospital pharmacies, retail pharmacies and online pharmacies. (clickpress.com)
Function1
- These channels are necessary for the normal function of organs such as the lungs and pancreas. (nih.gov)
Crucial1
- Barttin is a Cl- channel beta-subunit crucial for renal Cl- reabsorption and inner ear K+ secretion. (medlineplus.gov)
Cells2
- Antihypertensive DHPs act by blocking L-type voltage-dependent Ca++ channels and therefore cause the relaxation of arterial smooth muscle cells. (units.it)
- We think it simply keeps the channel on the surface of the cells for a longer period of time. (genengnews.com)
Water1
- Differentiation resulted in polarized expression of collecting duct water channels AQP2 and AQP3. (frontiersin.org)