scholarly journals THE MOLLUSC IONIC CURRENTS CHANGES AFTER ADMINISTRATION OF N-PHENYLALKYL DERIVATIVES OF TAURINE

2012 ◽  
Vol 10 (4) ◽  
pp. 67-72
Author(s):  
Anatoliy Ivanovich Vislobokov ◽  
Lyudmila Konstantinovna Khnychenko ◽  
Yuriy Dmitriyevich Ignatov ◽  
Nikolay Sergeyevich Sapronov ◽  
Petr Dmitriyevich Shabanov
Keyword(s):  
Lymnaea Stagnalis ◽  
Ionic Currents ◽  
Ionic Channels ◽  
Dependent Manner ◽  
Isolated Neurons ◽  
Sodium Potassium ◽  
Fixed Membrane ◽  
Kinetics Of ◽  
Dose Dependent ◽  
Derivatives Of

The transmembrane sodium, potassium and calcium ionic currents were studied after extracellular administration of N-phenylalkyl derivatives of taurine in concentrations 1, 10, 100 and 1000 mM. The method of intracellular dialysis with fixed membrane potential was used in model of isolated neurons of the mollusks Lymnaea stagnalis and Planorbarius corneus. The solutions containing 1 and 10 mM of the compounds studied did not change ionic channels activity in isolated neurons. Concentrations 100 and mM depressed reversibly all currents in the dose-dependent manner: taurine < TAU-02 < TAY-15 < TAU-60. The voltage-amplitude membrane characteristics as well as kinetics of the currents did not change.

scholarly journals Effect of dibazol and its new derivatives on the mollusk ionic channels

2013 ◽  
Vol 11 (3) ◽  
pp. 26-32
Author(s):  
Anatoliy Ivanovich Vislobokov ◽  
Leonid Vitalyevich Myznikov ◽  
Aleksandr Aleksandrovich Tarasenko ◽  
Petr Dmitriyevich Shabanov
Keyword(s):  
Lymnaea Stagnalis ◽  
Ionic Currents ◽  
Ionic Channels ◽  
Maximal Effect ◽  
Dependent Manner ◽  
Isolated Neurons ◽  
High Concentrations ◽  
Kinetics Of ◽  
Dose Dependent ◽  
Sodium And Potassium

The changes in transmembrane calcium, sodium and potassium ionic currents after extracellular administration of dibazol (2-(phenylmethyl)-1H-benzimidazol hydrochloride) and its two new derivatives in concentrations of 1, 10, 100 and 1000 µM were studied by the method of intracellular dialysis and fixation of membrane potential in isolated neurons of the Lymnaea stagnalis mollusk. Dibazol in concentrations of 1 and 10 µM effected slightly on the ionic currents. High concentrations of dibazol (100 and 1000 µM) inhibited all currents in dose dependent manner with maximal effect on potassium currents amplitude. ЕС50 were 7.4 мМ for INa, 4.0 мМ for ICa, 83.9 µM for IKs,1 (one group of neurons) and 2.9 мМ for IKs,2 (the another group of neurons). The voltage-amper membrane characteristics shift was not registered, but the kinetics of currents development was changed. Dibazol was more effective in inhibition of ionic currents compared to its structural analogs.

scholarly journals Modulation of electrical activity and ionic currents of isolated neurons by orexin A

2013 ◽  
Vol 11 (4) ◽  
pp. 54-60
Author(s):  
Petr Dmitriyevich Shabanov ◽  
Anatoliy Ivanovich Vislobokov
Keyword(s):  
Membrane Potential ◽  
Lymnaea Stagnalis ◽  
Ionic Currents ◽  
Maximal Effect ◽  
Dependent Manner ◽  
Isolated Neurons ◽  
Orexin A ◽  
High Concentrations ◽  
Kinetics Of ◽  
Dose Dependent

The changes in intracellular potential of resting (PR) and potential of action (PA) of the identified neurons of pedal and visceral ganglia of the CNS mollusk Planorbarius corneus registered by means of intracellular electrodes, and ionic currents of isolated neurons under fixed potential after administration of orexin A in concentrations 1, 10, 100 and 1000 µg/ml were studied by the method of fixation of membrane potential in isolated neurons of the Lymnaea stagnalis mollusk. Dibazol in concentrations of 1 and 10 µM effected slightly on the ionic currents. High concentrations of dibazol (100 and 1000 µM) inhibited all currents in dose dependent manner with maximal effect on potassium currents amplitude. ЕС50 were 7.4 мМ for INa, 4.0 мМ for ICa, 83.9 µM for IKs,1 (one group of neurons) and 2.9 мМ for IKs,2 (the another group of neurons). The voltage-amper membrane characteristics shift was not registered, but the kinetics of currents development was changed. Dibazol was more effective in inhibition of ionic currents compared to its structural analogs.

Membranotropic activity of taurine derivatives

2020 ◽  
Author(s):  
Petr D. Shabanov ◽  
Ludmila K. Khnychenko
Keyword(s):  
Sulfonic Acid ◽  
Lymnaea Stagnalis ◽  
Calcium Influx ◽  
Ionic Currents ◽  
Isolated Neurons ◽  
Excitable Cells ◽  
Potassium Efflux ◽  
Low Concentrations ◽  
High Concentrations ◽  
Derivatives Of

The aim of the work. To evaluate the effect of n-phenylalkyl derivatives of taurine on changes in transmembrane ion currents of potential-controlled ion channels of isolated neurons. Materials and methods. The method of intracellular dialysis and fixation of membrane potential on isolated neurons of the great pond truncatula (Lymnaea stagnalis) and hornbill (Planorbarius corneus) was used. The n-phenylalkyl derivatives of taurine (1-phenyl-2-isopropylaminoethanesulfonic acid; benzylaminoethane sulfonic acid isopropylamide; phenethylaminoethane sulfonic acid isopropylamide) or the comparison drug taurine was dissolved in external solutions and studied at concentrations of 1, 10, 100 and 1000 M. Results. The results demonstrate that n-phenilalkyl derivatives of taurine in low concentrations (1; 10 M) have a modulating effect on electrically excitable cells, and in high concentrations (100; 1000 M) reduce the sodium-calcium influx and potassium efflux ionic currents, have a channel blocking effect. Conclusion. N-phenylalkyl derivatives of taurine reduces the excitability of cells contribute to the suppression of synaptic potentials, ion gradients of the cells.

scholarly journals Kinetics of Mushroom Tyrosinase and Melanogenesis Inhibition byN-Acetyl-pentapeptides

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ching-Yi Lien ◽  
Ching-Yu Chen ◽  
Shih-Ting Lai ◽  
Chin-Feng Chan
Keyword(s):  
Kojic Acid ◽  
Lag Time ◽  
Melanoma Cells ◽  
Dependent Manner ◽  
Mushroom Tyrosinase ◽  
Inhibitory Effects ◽  
B16f10 Melanoma ◽  
B16f10 Melanoma Cells ◽  
Kinetics Of ◽  
Dose Dependent

We investigated the kinetics of 4N-acetyl-pentapeptides, Ac-P1, Ac-P2, Ac-P3, and Ac-P4, regarding inhibition of mushroom tyrosinase activity. The peptides sequences of Ac-P1, Ac-P2, Ac-P3, and Ac-P4 were Ac-RSRFK, Ac-KSRFR, Ac-KSSFR, and Ac-RSRFS, respectively. The 4N-acetyl-pentapeptides were able to reduce the oxidation ofL-DOPA by tyrosinase in a dose-dependent manner. Of the 4N-acetyl-pentapeptides, only Ac-P4 exhibited lag time (80 s) at a concentration of 0.5 mg/mL. The tyrosinase inhibitory effects of Ac-P4 (IC500.29 mg/mL) were more effective than those of Ac-P1, Ac-P2, and Ac-P3, in which IC50s were 0.75 mg/mL, 0.78 mg/mL, and 0.81 mg/mL, respectively. Kinetic analysis demonstrated that all 4N-acetyl-pentapeptides were mixed-type tyrosinase inhibitors. Furthermore, 0.1 mg/mL of Ac-P4 exhibited significant melanogenesis inhibition on B16F10 melanoma cells and was more effective than kojic acid. The melanogenesis inhibition of Ac-P4 was dose-dependent and did not induce any cytotoxicity on B16F10 melanoma cells.

scholarly journals Effects of penicillins and 6-aminohexanoic acid on the kinetics of human plasmin

1989 ◽  
Vol 260 (2) ◽  
pp. 609-612 ◽  
Author(s):  
A A A Higazi ◽  
M Mayer
Keyword(s):  
Active Site ◽  
Dependent Manner ◽  
Chromogenic Substrate ◽  
Regulatory Site ◽  
Amidolytic Activity ◽  
Plasmin Activity ◽  
Maximal Inhibition ◽  
Sigmoidal Curve ◽  
Kinetics Of ◽  
Dose Dependent

Human plasmin activity is inhibited by various penicillins in a dose-dependent manner. Ampicillin and cloxacillin produce a 50% inhibition of the globinolytic activity of plasmin at 4.5 and 5.3 mM respectively. A lower inhibitory capacity is displayed by carbenicillin. Assay of plasmin by its amidolytic activity on D-valyl-L-leucyl-L-lysine p-nitroanilide dihydrochloride showed that ampicillin at a concentration producing half-maximal inhibition converted the hyperbolic activity-substrate concentration curve into a sigmoidal curve. A similar conversion occurred in the presence of ampicillin when plasmin was assayed with an alternative chromogenic substrate, L-pyroglutamyl-glycyl-L-arginine p-nitroanilide hydrochloride 6-Aminohexanoic acid at 7.5 microM abolished the inhibition of plasmin induced by ampicillin. The present observations suggest that ampicillin interacts with plasmin at a regulatory site different from the active site of the enzyme. The effect of 6-aminohexanoic acid indicates that the lysine-binding site may be part of a regulatory site. It is possible that modulation of plasmin activity by ligands plays a role in the control of fibrinolysis.

scholarly journals Localization and differential induction of cytochrome P450IVA and acyl-CoA oxidase in rat liver

1991 ◽  
Vol 275 (1) ◽  
pp. 247-252 ◽  
Author(s):  
D R Bell ◽  
R G Bars ◽  
G G Gibson ◽  
C R Elcombe
Keyword(s):  
Peroxisome Proliferator ◽  
Peroxisome Proliferators ◽  
Dependent Manner ◽  
Early Markers ◽  
Acyl Coa Oxidase ◽  
Significant Change ◽  
Kinetics Of ◽  
Dose Dependent ◽  
Induced Proteins ◽  
Hepatic Cytochrome

The peroxisome proliferators are structurally diverse chemicals which induce hyperplasia, hypertrophy and the proliferation of peroxisomes in the rodent liver. Cytochrome P450IVA1 and peroxisomal enzymes, such as acyl-CoA oxidase, are induced and are early markers of treatment with peroxisome proliferators. In this study, rats were dosed intraperitoneally with the potent peroxisome proliferator methylclofenapate and the hepatic induction response was studied. There was no significant change in the enzyme activities of laurate hydroxylase (cytochrome P450IVA1) or acyl-CoA oxidase in the first 8 h after treatment, but the activities had doubled at 24 h, suggesting that these enzymes are not involved in the mediation of early events in peroxisome proliferation. Hepatic cytochrome P450IVA1 mRNA was significantly increased at 6 and 8 h after treatment, rising to 15-fold above control values at 30 h. In contrast, acyl-CoA oxidase mRNA showed no significant change in the first 8 h, but increased to 13-fold above control values at 24 and 30 h, thereby demonstrating different kinetics of induction of the two mRNAs. In order to determine whether cytochrome P450IVA1 and peroxisomal enzymes were included in the same cells, rats were treated daily with sub-maximal (2 or 5 mg/kg) and maximal (25 mg/kg) inducing doses of methylclofenapate for 4 days. The lobular distribution of induced proteins was determined immunocytochemically with antibodies raised against P450IVA1 and acyl-CoA oxidase. Livers from control animals showed minimal staining for both proteins. However, in the livers of animals treated with 2 or 5 mg of methylclofenapate/kg, both acyl-CoA and P450IVA immunostaining was increased, mainly in the centrilobular area. Immunostaining of serial sections revealed that these proteins were induced in the same region of the lobule. A maximal inducing dose of methylclofenapate (25 mg/kg) caused panlobular induction of both proteins. The results demonstrate that these proteins are induced in a dose-dependent manner in the same, spatially distinct, sensitive region of the liver lobule.

scholarly journals Synthesis and evaluation of some novel derivatives of 2-propoxybenzylidene isonicotinohydrazide for their potential antimicrobial activity

2012 ◽  
Vol 77 (5) ◽  
pp. 589-597 ◽  
Author(s):  
Manav Malhotra ◽  
Manu Arora ◽  
Abdul Samad ◽  
Kapendra Sahu ◽  
Priyanka Phogat ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Mannich Bases ◽  
Dependent Manner ◽  
Lung Adenocarcinoma Cell Line ◽  
Ic50 Values ◽  
Nmr Methods ◽  
Human Lung Adenocarcinoma Cell ◽  
Dose Dependent ◽  
Derivatives Of

A novel series of Mannich which contained isoniaside were prepared. First by the reaction of 2-propoxybenzaldehyde with isoniazid corresponding hydrazone (2a) was obtained. After that, product 2a after mannich reaction of aminomethylation with formaldehyde and secondary give amines (2b-2k). The inhibitory potencies of the synthesized compounds were assayed in vitro against a panel of microorganisms and against A549 human lung adenocarcinoma cell line. Compounds 2c and 2k displayed moderate to potent antimicrobial activity against all the tested strains and they also exhibited significant cytotoxicity in a dose-dependent manner with an IC50 values ranging from 2.84 to 8.55 (?g) and 0.007-0.030 (?M). The structures of newly synthesized compounds were evaluated by elemental and spectral (IR, 1HNMR, 13C-NMR) methods. The result demonstrates the potential and importance of developing new mannich bases which would be effective against resistant microbial strain and they may be useful leads for anticancer drug development in the future.

scholarly journals Pedigree analyses of yeast cells recovering from DNA damage allow assignment of lethal events to individual post-treatment generations.

Genetics ◽  
1990 ◽  
Vol 124 (1) ◽  
pp. 57-65
Author(s):  
F Klein ◽  
A Karwan ◽  
U Wintersberger
Keyword(s):  
Dna Damage ◽  
Post Treatment ◽  
Yeast Cells ◽  
Dependent Manner ◽  
The Third ◽  
Lethal Mutations ◽  
Dna Damaging Agents ◽  
Kinetics Of ◽  
Dose Dependent ◽  
Insight Into

Abstract Haploid cells of Saccharomyces cerevisiae were treated with different DNA damaging agents at various doses. A study of the progeny of individual such cells (by pedigree analyses up to the third generation) allowed the assignment of lethal events to distinct post treatment generations. By microscopically inspecting those cells which were not able to form visible colonies we could discriminate between cells dying from immediately effective lethal hits and those generating microcolonies (three to several hundred cells) probably as a consequence of lethal mutation(s). The experimentally obtained numbers of lethal events (which we call apparent lethal fixations) were mathematically transformed into mean probabilities of lethal fixations as taking place in cells of certain post treatment generations. Such analyses give detailed insight into the kinetics of lethality as a consequence of different kinds of DNA damage. For example, X-irradiated cells lost viability mainly by lethal hits (which we call 00-fixations); only at a higher dose also lethal mutations fixed in the cells that were in direct contact with the mutagen (which we call 0-fixations), but not in later generations, occurred. Ethyl methanesulfonate (EMS)-treated cells were hit by 00-fixations in a dose dependent manner; 0-fixations were not detected for any dose of EMS applied; the probability for fixation of lethal mutations was found equally high for cells of the first and second post treatment generation and, unexpectedly, was well above control in the third post-treatment generation. The distribution of all sorts of lethal fixations taken together, which occurred in the EMS-damaged cell families, was not random.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone as an ion exchange system: evidence for a link between mechanotransduction and metabolic needs

2002 ◽  
Vol 282 (4) ◽  
pp. E851-E864 ◽  
Author(s):  
A. Rubinacci ◽  
M. Covini ◽  
C. Bisogni ◽  
I. Villa ◽  
M. Galli ◽  
...  
Keyword(s):  
Current Density ◽  
Ex Vivo ◽  
Ionic Current ◽  
Extracellular Fluid ◽  
Ionic Currents ◽  
Dependent Manner ◽  
Metabolic Functions ◽  
Metatarsal Bones ◽  
Dose Dependent

To detect whether the mutual interaction occurring between the osteocytes-bone lining cells system (OBLCS) and the bone extracellular fluid (BECF) is affected by load through a modification of the BECF-extracellular fluid (ECF; systemic extracellular fluid) gradient, mice metatarsal bones immersed in ECF were subjected ex vivo to a 2-min cyclic axial load of different amplitudes and frequencies. The electric (ionic) currents at the bone surface were measured by a vibrating probe after having exposed BECF to ECF through a transcortical hole. The application of different loads and different frequencies increased the ionic current in a dose-dependent manner. The postload current density subsequently decayed following an exponential pattern. Postload increment's amplitude and decay were dependent on bone viability. Dummy and static loads did not induce current density modifications. Because BECF is perturbed by loading, it is conceivable that OBLCS tends to restore BECF preload conditions by controlling ion fluxes at the bone-plasma interface to fulfill metabolic needs. Because the electric current reflects the integrated activity of OBLCS, its evaluation in transgenic mice engineered to possess genetic lesions in channels or matrix constituents could be helpful in the characterization of the mechanical and metabolic functions of bone.

EVALUATION OF DIURETIC ACTIVITY OF MILLETTIA PINNATA IN RATS

INDIAN DRUGS ◽  
2014 ◽  
Vol 51 (05) ◽  
pp. 39-42
Author(s):  
B. Deepti ◽  
◽  
P. Srinivasa Babu ◽  
K. Manasa ◽  
N. Rishita
Keyword(s):  
Ethyl Acetate ◽  
Petroleum Ether ◽  
Petroleum Ether Extract ◽  
Dependent Manner ◽  
Diuretic Activity ◽  
Urine Ph ◽  
Sodium Potassium ◽  
Millettia Pinnata ◽  
Dose Dependent ◽  
Ethyl Acetate Extracts

The purpose of the present study was to evaluate the diuretic activity of Millettia pinnata in experimental animals. Randomly selected animals were divided into five groups of six animals each. The various extracts of the bark of Millettia pinnata, that is, petroleum ether, ethyl acetate and methanol extracts were administered orally at a dose of 50 and 100 mg/kg. Parameters like volume of urine, pH of urine, conductivity and urinary electrolyte concentrations like sodium, potassium and chloride were studied and compared with the standard furosemide. The methanol extract of Millettia pinnata increased the urine output in a dose-dependent manner than petroleum ether and ethyl acetate extracts, whereas petroleum ether extract was significant when compared to ethyl acetate extract. From the present study, it can be concluded that Millettia pinnata has diuretic property.

Sign in / Sign up

Export Citation Format

Share Document