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Tetsuyuki Nasu - One of the best experts on this subject based on the ideXlab platform.
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the binding of cadmium ions to the smooth muscle of guinea pig Taenia Coli
Pharmacology & Toxicology, 2009Co-Authors: Tetsuyuki NasuAbstract:: Taenia Coli was used to study the property of binding of Cd2+. The Scatchard plots of cadmium uptake showed that two qualitative Cd2+ binding sites (high and low affinity binding sites) exist in Taenia Coli. Decrease in Ca2+ concentration in the medium did increase the cadmium binding. The Scatchard analysis of Cd2+ binding in Taenia Coli at 4 degrees indicated a single class of binding sites (only high affinity binding sites). These findings suggest that the greater number of high affinity Cd2+ binding sites in Taenia Coli may relate to the binding to cell membrane. Further, it was postulated that some of low affinity binding sites in Taenia Coli may reflect intracellular accumulation, indicating the action on the contractile system.
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Effects of cadmium ions, D-600 and chlorpromazine on the skinned smooth muscle of guinea-pig Taenia Coli.
General Pharmacology-the Vascular System, 2002Co-Authors: Tetsuyuki Nasu, Yukio IshidaAbstract:Abstract 1. 1. The effects of Cd2+ on the skinned Taenia Coli were compared with that of Ca2+ channel blocker, D-600 and calmodulin inhibitor, chlorpromazine. The Cd2+ (0.001–0.5 mM) inhibited the contraction of skinned fibres in a dose-dependent manner. 2. 2. In contrast, the contraction of skinned fibres was not inhibited by pretreatment with 1 × 10−6 M D-600. However, chlorpromazine (10−4 M) inhibited the contraction of skinned Taenia Coli. 3. 3. The inhibition of contraction by Cd2+ in skinned Taenia Coli was completely reversed by washing with solution containing EDTA, following a treatment with 0.5 mM Cd2+ for 15 min. 4. 4. The skinned fibres had rapidly taken up a far greater amount of Cd2+ than intact muscle of Taenia Coli. EDTA increased Cd2+ efflux in skinned fibres and only 5% of the original tissue content retained. 5. 5. Thus, EDTA, which was ineffective on intact Taenia Coli, can be considered to act on Cd2+ of intracellular compartment after disruption of the cell membrane with saponin. 6. 6. In conclusion, there is the possibility that Cd2+ inhibits the contractile system, such as contractile proteins and calmodulin, which results in tension inhibitory effect.
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Temperature dependency of cadmium uptake and relaxant effect of cadmium in guinea-pig Taenia Coli
General Pharmacology-the Vascular System, 2002Co-Authors: Tetsuyuki Nasu, Hiroshi KoshibaAbstract:1. 1. Cadmium fluxes were studied under low temperature in order to assess the site of action of Cd2+ in Taenia Coli. 2. 2. Following a treatment with 0.5 mM Cd2+ for 30 min at 37°C, the responses to high-K+ were not reversed after washing with medium containing 0.5 mM disodium edetate (EDTA). However, at 30 min preincubation with 0.5 mM Cd2+ at 4°C, the responses markedly returned by the washing. 3. 3. The cadmium uptake was much slower at 4°C. 4. 4. The cadmium in muscle preincubated at 4°C was markedly eliminated by EDTA. Thus, the increase in the size of the fraction of total cadmium not eliminated by EDTA was temperature dependent. 5. 5. These data suggest the possibility that the total cadmium not eliminated by EDTA in Taenia Coli may be accumulated in the intracellular compartment where EDTA cannot reach.
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Relaxant effects of mercury and mercury uptake in the smooth muscle of guinea-pig Taenia Coli.
General Pharmacology-the Vascular System, 2002Co-Authors: Tetsuyuki Nasu, Ei-ichi Nakai, Gyobu Kazuyoshi, Ishida YukioAbstract:Abstract 1. 1. Hg 2+ (0.005-0.5 mM) induced a concentration-dependent reduction on high-K + -induced contraction of Taenia Coli. 2. 2. The K + -induced increase in 45 Ca uptake was significantly reduced in the presence of Hg 2+ (0.05-0.5 mM). 3. 3. The contractions of the glycerinated Taenia Coli were inhibited by an increase in Hg 2+ concentration. 4. 4. Mercury uptake increased along the duration of Hg 2+ incubation. 5. 5. When muscles were rinsed with a medium containing 5 mM EDTA after 0.5 mM Hg 2+ treatment for 90 min about 30% of the original level of tissue mercury was retained. 6. 6. Possible mechanism for the tension inhibitory action of Hg 2+ include: (1) that Hg 2+ bound to cell membrane initially interferes with the permeability of Ca 2+ and that (2) the cellular mercury fraction that is not eliminated by EDTA subsequently correlates with the tension inhibitory action.
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Analysis of mercury ions binding to the smooth muscle of guinea-pig Taenia Coli
General Pharmacology-the Vascular System, 2002Co-Authors: Tetsuyuki Nasu, Kazuyoshi Gyobu, Yukio IshidaAbstract:Abstract 1. 1.|Mercury uptake to Taenia Coli increased with an increase of the Hg 2+ concentration (0.05-5 mmol/1). The Scatchard plots of mercury uptake showed that two qualitative Hg 2+ binding sites (high and low affinity sites) exist in Taenia Coli. 2. 2.|The Scatchard analysis of Hg 2+ binding at 4°C indicated a single class of binding site (high affinity binding site only). 3. 3.|These results indicate that Hg 2+ binds to high affinity binding sites of cell membrane and Hg 2+ of low affinity binding sites may reflect intracellular accumulation in Taenia Coli.
Hideaki Karaki - One of the best experts on this subject based on the ideXlab platform.
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MOVEMENTS OF CALCIUM DURING TENSION DEVE-LOPMENT INDUCED BY BARIUM AND HIGH-POTASSIUM IN GUINEA PIG Taenia Coli
Japanese Journal of Pharmacology, 2019Co-Authors: Hideaki Karaki, Miyoshi Ikeda, Norimoto UrakawaAbstract:In previous publications it was reported that barium in concentrations from 0.5 to 20 mM induced tension development in isolated guinea pig Taenia Coli, which response was dependent on the presence of external calcium (1), and that total Ca content did not change but 45Ca uptake of the cellular fraction which did not exchange within 4 minutes increased above control level during Ba-induced tension development (2). It was also mentioned that Ba increased Ca entry in Taenia Coli and that this Ca probably plays an essential role during tension development (2). On the other hand, hypertonically added 40 mM K-induced tonic tension development in Taenia Coli was noted to be composed of phasic and tonic phases and it was proposed that in the phasic contraction, sufficient Ca is released from a cellular site to initiate contraction, whereas in the tonic contraction enough Ca crosses the membrane to initiate and also to maintain contraction(3). However, the movement of Ca in the above processes has not been studied systematically. This work was undertaken to study the movement of Ca in Taenia Coli during Ba- and high-K-induced tension developments by investigating the total Ca, 45Ca uptake and efflux and 45Ca uptake of the cellular fraction which did not exchange within 4 minutes. A part of this work has already been reported (2, 4).
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Increase in 85 Sr uptake by elevated concentration of K in guinea pig Taenia Coli.
Japanese Journal of Pharmacology, 2019Co-Authors: Hideaki Karaki, Norimoto UrakawaAbstract:Abstract In Taenia Coli, 40 mM K induced a tonic contraction accompanied by an increased oxygen consumption. When Ca in the bathing medium was replaced by Sr, 40 mM K developed little tension but increased oxygen consumption to a similar degree as that in normal medium (1). Although the movement of Ca and its possible relationship to tension development and also to oxygen consumption have been reported in Taenia Coli in the presence of 40 mM K (2, 3), there are few data concerning a movement of Sr ion in smooth muscle. In the present report 85Sr uptake by Taenia Coli was studied in comparison with 45Ca movement.
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no donor sodium nitroprusside inhibits excitation contraction coupling in guinea pig Taenia Coli
American Journal of Physiology-gastrointestinal and Liver Physiology, 2000Co-Authors: Hiroshi Ozaki, Seongchun Kwon, Hideaki KarakiAbstract:In guinea pig Taenia Coli, the nitric oxide (NO) donor sodium nitroprusside (SNP, 1 μM) reduced the carbachol-stimulated increases in muscle force in parallel with a decrease in intracellular Ca2+ ...
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calyculin a increases voltage dependent inward current in smooth muscle cells isolated from guinea pig Taenia Coli
Cellular and Molecular Life Sciences, 1991Co-Authors: T Usuki, Hideaki Karaki, Hiroshi Ozaki, K Obara, T Someya, Nobuhiro Fusetani, H YabuAbstract:The effects of a potent phosphatase inhibitor, calyculin A (CL-A), on inward currents in guinea pig Taenia Coli smooth muscle cells were examined. CL-A increased the inward current, and this effect of CL-A was inhibited by a protein kinase C inhibitor, H-7, and by nifedipine. Phorbol 12,13-dibutyrate, an activator of protein kinase C, also increased the inward current and this effect was antagonized by H-7. These results suggest that in guinea pig Taenia Coli smooth muscle cells CL-A may facilitate the opening of thel-type Ca2+ channels through the protein kinase C-dependent phosphorylation system.
Ursula Windscheif - One of the best experts on this subject based on the ideXlab platform.
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inhibitory action of ppads on relaxant responses to adenine nucleotides or electrical field stimulation in guinea pig Taenia Coli and rat duodenum
British Journal of Pharmacology, 1995Co-Authors: Ursula Windscheif, Otmar Pfaff, Hans G Baumert, Geoffrey Burastock, A U Ziganshin, Charles H V Hoyle, Ernst Mutschler, Gunter LambrechtAbstract:1. The effect of pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) on the relaxant response to adenine nucleotides was examined in the carbachol-contracted guinea-pig Taenia Coli and rat duodenum, two tissues possessing P2y-purinoceptors. In addition, in the Taenia Coli PPADS was investigated for its effect on relaxations evoked by adenosine, noradrenaline and electrical field stimulation. In order to assess the selectivity of PPADS between P2-purinoceptor blockade and ectonucleotidase activity, its influence on ATP degradation was studied in guinea-pig Taenia Coli. 2. The resulting rank order of potency for the adenine nucleotides in guinea-pig Taenia Coli was: 2-methylthio ATP >> ATP > alpha,beta-methylene ATP with the respective pD2-values 7.96 +/- 0.08 (n = 23), 6.27 +/- 0.12 (n = 21) and 5.88 +/- 0.04 (n = 24). 3. In guinea-pig Taenia Coli, PPADS (10-100 microM) caused a consistent dextral shift of the concentration-response curve (CRC) of 2-methylthio ATP and ATP resulting in a biphasic Schild plot. A substantial shift was only observed at 100 microM PPADS, the respective pA2-values at this particular concentration were 5.26 +/- 0.16 (n = 5) and 5.15 +/- 0.13 (n = 6). Lower concentrations of PPADS (3-30 microM) antagonized the relaxant effects to alpha,beta-methylene ATP in a surmountable manner. An extensive shift of the CRC was produced only by 30 microM PPADS (pA2 = 5.97 +/- 0.08, n = 6), and the Schild plot was again biphasic.(ABSTRACT TRUNCATED AT 250 WORDS)
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Inhibitory action of PPADS on relaxant responses to adenine nucleotides or electrical field stimulation in guinea‐pig Taenia Coli and rat duodenum
British Journal of Pharmacology, 1995Co-Authors: Ursula Windscheif, Otmar Pfaff, Hans G Baumert, Geoffrey Burastock, A U Ziganshin, Charles H V Hoyle, Ernst Mutschler, Gunter LambrechtAbstract:1. The effect of pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) on the relaxant response to adenine nucleotides was examined in the carbachol-contracted guinea-pig Taenia Coli and rat duodenum, two tissues possessing P2y-purinoceptors. In addition, in the Taenia Coli PPADS was investigated for its effect on relaxations evoked by adenosine, noradrenaline and electrical field stimulation. In order to assess the selectivity of PPADS between P2-purinoceptor blockade and ectonucleotidase activity, its influence on ATP degradation was studied in guinea-pig Taenia Coli. 2. The resulting rank order of potency for the adenine nucleotides in guinea-pig Taenia Coli was: 2-methylthio ATP >> ATP > alpha,beta-methylene ATP with the respective pD2-values 7.96 +/- 0.08 (n = 23), 6.27 +/- 0.12 (n = 21) and 5.88 +/- 0.04 (n = 24). 3. In guinea-pig Taenia Coli, PPADS (10-100 microM) caused a consistent dextral shift of the concentration-response curve (CRC) of 2-methylthio ATP and ATP resulting in a biphasic Schild plot. A substantial shift was only observed at 100 microM PPADS, the respective pA2-values at this particular concentration were 5.26 +/- 0.16 (n = 5) and 5.15 +/- 0.13 (n = 6). Lower concentrations of PPADS (3-30 microM) antagonized the relaxant effects to alpha,beta-methylene ATP in a surmountable manner. An extensive shift of the CRC was produced only by 30 microM PPADS (pA2 = 5.97 +/- 0.08, n = 6), and the Schild plot was again biphasic.(ABSTRACT TRUNCATED AT 250 WORDS)
Charles H V Hoyle - One of the best experts on this subject based on the ideXlab platform.
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inhibitory action of ppads on relaxant responses to adenine nucleotides or electrical field stimulation in guinea pig Taenia Coli and rat duodenum
British Journal of Pharmacology, 1995Co-Authors: Ursula Windscheif, Otmar Pfaff, Hans G Baumert, Geoffrey Burastock, A U Ziganshin, Charles H V Hoyle, Ernst Mutschler, Gunter LambrechtAbstract:1. The effect of pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) on the relaxant response to adenine nucleotides was examined in the carbachol-contracted guinea-pig Taenia Coli and rat duodenum, two tissues possessing P2y-purinoceptors. In addition, in the Taenia Coli PPADS was investigated for its effect on relaxations evoked by adenosine, noradrenaline and electrical field stimulation. In order to assess the selectivity of PPADS between P2-purinoceptor blockade and ectonucleotidase activity, its influence on ATP degradation was studied in guinea-pig Taenia Coli. 2. The resulting rank order of potency for the adenine nucleotides in guinea-pig Taenia Coli was: 2-methylthio ATP >> ATP > alpha,beta-methylene ATP with the respective pD2-values 7.96 +/- 0.08 (n = 23), 6.27 +/- 0.12 (n = 21) and 5.88 +/- 0.04 (n = 24). 3. In guinea-pig Taenia Coli, PPADS (10-100 microM) caused a consistent dextral shift of the concentration-response curve (CRC) of 2-methylthio ATP and ATP resulting in a biphasic Schild plot. A substantial shift was only observed at 100 microM PPADS, the respective pA2-values at this particular concentration were 5.26 +/- 0.16 (n = 5) and 5.15 +/- 0.13 (n = 6). Lower concentrations of PPADS (3-30 microM) antagonized the relaxant effects to alpha,beta-methylene ATP in a surmountable manner. An extensive shift of the CRC was produced only by 30 microM PPADS (pA2 = 5.97 +/- 0.08, n = 6), and the Schild plot was again biphasic.(ABSTRACT TRUNCATED AT 250 WORDS)
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Inhibitory action of PPADS on relaxant responses to adenine nucleotides or electrical field stimulation in guinea‐pig Taenia Coli and rat duodenum
British Journal of Pharmacology, 1995Co-Authors: Ursula Windscheif, Otmar Pfaff, Hans G Baumert, Geoffrey Burastock, A U Ziganshin, Charles H V Hoyle, Ernst Mutschler, Gunter LambrechtAbstract:1. The effect of pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) on the relaxant response to adenine nucleotides was examined in the carbachol-contracted guinea-pig Taenia Coli and rat duodenum, two tissues possessing P2y-purinoceptors. In addition, in the Taenia Coli PPADS was investigated for its effect on relaxations evoked by adenosine, noradrenaline and electrical field stimulation. In order to assess the selectivity of PPADS between P2-purinoceptor blockade and ectonucleotidase activity, its influence on ATP degradation was studied in guinea-pig Taenia Coli. 2. The resulting rank order of potency for the adenine nucleotides in guinea-pig Taenia Coli was: 2-methylthio ATP >> ATP > alpha,beta-methylene ATP with the respective pD2-values 7.96 +/- 0.08 (n = 23), 6.27 +/- 0.12 (n = 21) and 5.88 +/- 0.04 (n = 24). 3. In guinea-pig Taenia Coli, PPADS (10-100 microM) caused a consistent dextral shift of the concentration-response curve (CRC) of 2-methylthio ATP and ATP resulting in a biphasic Schild plot. A substantial shift was only observed at 100 microM PPADS, the respective pA2-values at this particular concentration were 5.26 +/- 0.16 (n = 5) and 5.15 +/- 0.13 (n = 6). Lower concentrations of PPADS (3-30 microM) antagonized the relaxant effects to alpha,beta-methylene ATP in a surmountable manner. An extensive shift of the CRC was produced only by 30 microM PPADS (pA2 = 5.97 +/- 0.08, n = 6), and the Schild plot was again biphasic.(ABSTRACT TRUNCATED AT 250 WORDS)
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activation of p1 and p2y purinoceptors by adp ribose in the guinea pig Taenia Coli but not of p2x purinoceptors in the vas deferens
British Journal of Pharmacology, 1992Co-Authors: Charles H V Hoyle, Gareth A EdwardsAbstract:1. The activity of adenosine 5'-diphosphoribose (ADP-ribose), a ribosylated purine nucleotide, was investigated on the carbachol-contracted Taenia Coli, a tissue possessing P1- (A2) and P2Y-purinoceptors and on the guinea-pig vas deferens which possesses P2X-purinoceptors. 2. In the vas deferens, where ATP (1 microM-1 mM) produced concentration-dependent contractions, ADP-ribose was without effect at concentrations up to 1 mM. 3. In the Taenia Coli, ADP-ribose (0.1 microM-1 mM) produced concentration-dependent relaxations with a potency similar to that of adenosine, but less than that of ATP. The pD2 values for ADP-ribose, adenosine and ATP were 4.5 +/- 0.07 (27), 4.4 +/- 0.10 (9) and 5.5 +/- 0.14 (21), respectively. The time-course of the relaxations elicited by ADP-ribose was found to be significantly longer than that for ATP and significantly shorter than that for adenosine. 4. The P1-purinoceptor antagonist, 8-phenyltheophylline (5 microM), produced parallel rightward shifts in the concentration-response curves of the relaxations of the Taenia Coli elicited by ADP-ribose and adenosine but not ATP. 5. Dipyridamole (0.3 microM), a purine nucleoside uptake inhibitor, potentiated the responses to adenosine and ADP-ribose in the Taenia Coli. These potentiations were sensitive to 8-phenyltheophylline (5 microM). 6. Reactive blue 2, a P2Y-purinoceptor antagonist, antagonized the inhibitory responses of ADP-ribose and ATP in the Taenia Coli, without significantly altering the inhibitory responses of either adenosine or noradrenaline.(ABSTRACT TRUNCATED AT 250 WORDS)
Gunter Lambrecht - One of the best experts on this subject based on the ideXlab platform.
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inhibitory action of ppads on relaxant responses to adenine nucleotides or electrical field stimulation in guinea pig Taenia Coli and rat duodenum
British Journal of Pharmacology, 1995Co-Authors: Ursula Windscheif, Otmar Pfaff, Hans G Baumert, Geoffrey Burastock, A U Ziganshin, Charles H V Hoyle, Ernst Mutschler, Gunter LambrechtAbstract:1. The effect of pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) on the relaxant response to adenine nucleotides was examined in the carbachol-contracted guinea-pig Taenia Coli and rat duodenum, two tissues possessing P2y-purinoceptors. In addition, in the Taenia Coli PPADS was investigated for its effect on relaxations evoked by adenosine, noradrenaline and electrical field stimulation. In order to assess the selectivity of PPADS between P2-purinoceptor blockade and ectonucleotidase activity, its influence on ATP degradation was studied in guinea-pig Taenia Coli. 2. The resulting rank order of potency for the adenine nucleotides in guinea-pig Taenia Coli was: 2-methylthio ATP >> ATP > alpha,beta-methylene ATP with the respective pD2-values 7.96 +/- 0.08 (n = 23), 6.27 +/- 0.12 (n = 21) and 5.88 +/- 0.04 (n = 24). 3. In guinea-pig Taenia Coli, PPADS (10-100 microM) caused a consistent dextral shift of the concentration-response curve (CRC) of 2-methylthio ATP and ATP resulting in a biphasic Schild plot. A substantial shift was only observed at 100 microM PPADS, the respective pA2-values at this particular concentration were 5.26 +/- 0.16 (n = 5) and 5.15 +/- 0.13 (n = 6). Lower concentrations of PPADS (3-30 microM) antagonized the relaxant effects to alpha,beta-methylene ATP in a surmountable manner. An extensive shift of the CRC was produced only by 30 microM PPADS (pA2 = 5.97 +/- 0.08, n = 6), and the Schild plot was again biphasic.(ABSTRACT TRUNCATED AT 250 WORDS)
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Inhibitory action of PPADS on relaxant responses to adenine nucleotides or electrical field stimulation in guinea‐pig Taenia Coli and rat duodenum
British Journal of Pharmacology, 1995Co-Authors: Ursula Windscheif, Otmar Pfaff, Hans G Baumert, Geoffrey Burastock, A U Ziganshin, Charles H V Hoyle, Ernst Mutschler, Gunter LambrechtAbstract:1. The effect of pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS) on the relaxant response to adenine nucleotides was examined in the carbachol-contracted guinea-pig Taenia Coli and rat duodenum, two tissues possessing P2y-purinoceptors. In addition, in the Taenia Coli PPADS was investigated for its effect on relaxations evoked by adenosine, noradrenaline and electrical field stimulation. In order to assess the selectivity of PPADS between P2-purinoceptor blockade and ectonucleotidase activity, its influence on ATP degradation was studied in guinea-pig Taenia Coli. 2. The resulting rank order of potency for the adenine nucleotides in guinea-pig Taenia Coli was: 2-methylthio ATP >> ATP > alpha,beta-methylene ATP with the respective pD2-values 7.96 +/- 0.08 (n = 23), 6.27 +/- 0.12 (n = 21) and 5.88 +/- 0.04 (n = 24). 3. In guinea-pig Taenia Coli, PPADS (10-100 microM) caused a consistent dextral shift of the concentration-response curve (CRC) of 2-methylthio ATP and ATP resulting in a biphasic Schild plot. A substantial shift was only observed at 100 microM PPADS, the respective pA2-values at this particular concentration were 5.26 +/- 0.16 (n = 5) and 5.15 +/- 0.13 (n = 6). Lower concentrations of PPADS (3-30 microM) antagonized the relaxant effects to alpha,beta-methylene ATP in a surmountable manner. An extensive shift of the CRC was produced only by 30 microM PPADS (pA2 = 5.97 +/- 0.08, n = 6), and the Schild plot was again biphasic.(ABSTRACT TRUNCATED AT 250 WORDS)