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Makrane H, Aziz M, Mekhfi H, Ziyyat A, Legssyer A, Melhaoui A, Berrabah M, Bnouham M, Alem C, Elombo FK, Gressier B, Desjeux JF, Eto B. Origanum majorana L. extract exhibit positive cooperative effects on the main mechanisms involved in acute infectious diarrhea. JOURNAL OF ETHNOPHARMACOLOGY 2019; 239:111503. [PMID: 30217790 DOI: 10.1016/j.jep.2018.09.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/09/2018] [Accepted: 09/03/2018] [Indexed: 06/08/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Origanum majorana L. (Lamiaceae) is commonly used in Moroccan folk medicine to treat infantile colic, abdominal discomfort and diarrhea. Liquid stools and abdominal discomfort observed in acute infectious diarrhea are the consequences of imbalance between intestinal water secretion and absorption in the lumen, and relaxation of smooth muscle surrounding the intestinal mucosa. AIM OF THE STUDY The objective of our study was to see if aqueous extract of Origanum majorana L. (AEOM) may exhibit an effect on those deleterious mechanisms. MATERIALS AND METHODS The effect of AEOM on electrogenic Cl- secretion and Na+ absorption, the two main mechanisms underlying water movement in the intestine, was assessed on intestinal pieces of mice intestine mounted, in vitro, in Ussing chambers. AEOM effect on muscle relaxation was measured on rat intestinal smooth muscle mounted in an isotonic transducer. RESULTS 1) AEOM placed on the serosal (i.e. blood) side of the piece of jejunum entirely inhibited in a concentration-dependent manner the Forskolin-induced electrogenic chloride secretion, with an IC50 = 654 ± 8 µg/mL. 2) AEOM placed on the mucosal (i.e. luminal) side stimulated in a concentration-dependent manner an electrogenic Na+ absorption, with an IC50 = 476.9 ± 1 µg/mL. 3) AEOM (1 mg/mL) inhibition of Forskolin-induced electrogenic secretion was almost entirely prevented by prior exposure to Ca++ channels or neurotransmitters inhibitors. 4) AEOM (1 mg/mL) proabsorptive effect was greater in the ileum and progressively declined in the jejunum, distal colon and proximal colon (minimal). 5) AEOM inhibited in a concentration-dependent manner smooth muscle Carbachol or KCl induced contraction, with an IC50 = 1.64 ± 0.2 mg/mL or 1.92 ± 0.8 mg/mL, respectively. CONCLUSION the present results indicate that aqueous extract of Origanum majorana L. exhibit positive cooperative effects on the main mechanisms that are involved in acute infectious diarrhea.
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Affiliation(s)
- Hanane Makrane
- Laboratory of Physiology, Genetic and Ethnopharmacology, Faculty of Sciences, Mohammed The First University, PB. 717, 60000 Oujda, Morocco
| | - Mohammed Aziz
- Laboratory of Physiology, Genetic and Ethnopharmacology, Faculty of Sciences, Mohammed The First University, PB. 717, 60000 Oujda, Morocco
| | - Hassane Mekhfi
- Laboratory of Physiology, Genetic and Ethnopharmacology, Faculty of Sciences, Mohammed The First University, PB. 717, 60000 Oujda, Morocco
| | - Abderrahim Ziyyat
- Laboratory of Physiology, Genetic and Ethnopharmacology, Faculty of Sciences, Mohammed The First University, PB. 717, 60000 Oujda, Morocco
| | - Abdelkhaleq Legssyer
- Laboratory of Physiology, Genetic and Ethnopharmacology, Faculty of Sciences, Mohammed The First University, PB. 717, 60000 Oujda, Morocco
| | - Ahmed Melhaoui
- Laboratory of Organic Chemistry, Macromolecular and Natural Products, Faculty of Sciences, Mohammed The First University, PB. 717, 60000 Oujda, Morocco
| | - Mohamed Berrabah
- Laboratory of Chemistry, Mineral and Analytical Solid, Department of Chemistry, Faculty of Sciences, Mohammed The First University, PB. 717, 60000 Oujda, Morocco
| | - Mohamed Bnouham
- Laboratory of Physiology, Genetic and Ethnopharmacology, Faculty of Sciences, Mohammed The First University, PB. 717, 60000 Oujda, Morocco
| | - Chakib Alem
- Laboratory of Biochemistry, Department of Biology, Faculty of Sciences & Techniques, Errachidia, Morocco
| | - Ferdinand Kouoh Elombo
- Laboratoires TBC, Faculty of Pharmaceutical and Biological Sciences, Lille, France; Laboratory of Pharmacology, Pharmacokinetics, and Clinical Pharmacy, Faculty of Pharmaceutical and Biological Sciences, Lille, France
| | - Bernard Gressier
- Laboratory of Pharmacology, Pharmacokinetics, and Clinical Pharmacy, Faculty of Pharmaceutical and Biological Sciences, Lille, France
| | | | - Bruno Eto
- Laboratoires TBC, Faculty of Pharmaceutical and Biological Sciences, Lille, France.
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González-Montelongo MC, Marín R, Gómez T, Marrero-Alonso J, Díaz M. Androgens induce nongenomic stimulation of colonic contractile activity through induction of calcium sensitization and phosphorylation of LC20 and CPI-17. Mol Endocrinol 2010; 24:1007-23. [PMID: 20207835 DOI: 10.1210/me.2009-0472] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We show that androgens, testosterone and 5alpha-dihydrotestosterone (DHT), acutely (approximately 40 min) provoke the mechanical potentiation of spontaneous and agonist-induced contractile activity in mouse colonic longitudinal smooth muscle. The results using flutamide, finasteride, cycloheximide, and actinomycin D indicate that androgen-induced potentiation is dependent on androgen receptors, requires reduction of testosterone to DHT, and occurs independently of transcriptional and translational events. Using permeabilized colonic smooth muscle preparations, we could demonstrate that mechanical potentiation is entirely due to calcium sensitization of contractile machinery. In addition, DHT (10 nm) increased phosphorylation of both 20-kDa myosin light chain (LC(20)) [regulatory myosin light chain, (MLC)] and CPI-17 (an endogenous inhibitor of MLC phosphatase). Paralleling these findings, inhibition of Rho-associated Rho kinase (ROK) and/or protein kinase C (PKC) with, respectively, Y27632 and chelerythrine, prevented LC(20) phosphorylation and abolished calcium sensitization. In addition, inhibition of ROK prevents CPI-17 phosphorylation, indicating that ROK is located upstream PKC-mediated CPI-17 modulation in the signalling cascade. Additionally, androgens induce a rapid activation of RhoA and its translocation to the plasma membrane to activate ROK. The results demonstrate that androgens induce sensitization of colonic smooth muscle to calcium through activation of ROK, which in turn, activates PKC to induce CPI-17 phosphorylation. Activation of this pathway induces a potent steady stimulation of LC(20) by inhibiting MLC phosphatase and displacing the equilibrium of the regulatory subunit towards its phosphorylated state. This is the first demonstration that colonic smooth muscle is a physiological target for androgen hormones, and that androgens modulate force generation of smooth muscle contractile machinery through nongenomic calcium sensitization pathways.
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Affiliation(s)
- María C González-Montelongo
- Laboratory of Membrane Physiology and Biophysics, Department of Animal Biology, University of La Laguna, Tenerife 38206, Spain
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Boiko OV, Manukhin BN. The significance of extracellular Ca2+ in contractile responses of chick amnion. Russ J Dev Biol 2009. [DOI: 10.1134/s106236040904002x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Zhou H, Kong DH, Pan QW, Wang HH. Sources of calcium in agonist-induced contraction of rat distal colon smooth muscle in vitro. World J Gastroenterol 2008; 14:1077-83. [PMID: 18286690 PMCID: PMC2689411 DOI: 10.3748/wjg.14.1077] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To study the origin of calcium necessary for agonist-induced contraction of the distal colon in rats.
METHODS: The change in intracellular calcium concentration ([Ca2+]i) evoked by elevating external Ca2+ was detected by fura 2/AM fluorescence. Contractile activity was measured with a force displacement transducer. Tension was continuously monitored and recorded using a Powerlab 4/25T data acquisition system with an ML110 bridge bioelectric physiographic amplifier.
RESULTS: Store depletion induced Ca2+ influx had an effect on [Ca2+]i. In nominally Ca2+-free medium, the sarco-endoplasmic reticulum Ca2+-ATPase inhibitor thapsigargin (1 &mgr;mol/L) increased [Ca2+]i from 68 to 241 nmol/L, and to 458 (P < 0.01) and 1006 nmol/L (P < 0.01), respectively, when 1.5 mmol/L and 3.0 mmol/L extracellular Ca2+ was reintroduced. Furthermore, the change in [Ca2+]i was observed with verapamil (5 &mgr;mol/L), La3+ (1 mmol/L) or KCl (40 mmol/L) in the bathing solution. These channels were sensitive to La3+ (P < 0.01), insensitive to verapamil, and voltage independent. In isolated distal colons we found that in normal Krebs solution, contraction induced by acetylcholine (ACh) was partially inhibited by verapamil, and the inhibitory rate was 41% (P < 0.05). On the other hand, in Ca2+-free Krebs solution, ACh induced transient contraction due to Ca2+ release from the intracellular stores. The transient contraction lasted until the Ca2+ store was depleted. Restoration of extracellular Ca2+ in the presence of atropine produced contraction, mainly due to Ca2+ influx. Such contraction was not inhibited by verapamil, but was decreased by La3+ (50 &mgr;mol/L) from 0.96 to 0.72 g (P < 0.01).
CONCLUSION: The predominant source of activator Ca2+ for the contractile response to agonist is extracellular Ca2+, and intracellular Ca2+ has little role to play in mediating excitation-contraction coupling by agonists in rat distal colon smooth muscle in vitro. The influx of extracellular Ca2+ is mainly mediated through voltage-, receptor- and store-operated Ca2+ channels, which can be used as an alternative to develop new drugs targeted on the dysfunction of digestive tract motility.
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Takeuchi T, Nakajima H, Hata F, Azuma YT. A minor role for Ca2+ sensitization in sustained contraction through activation of muscarinic receptor in circular muscle of rat distal colon. Pflugers Arch 2007; 454:565-74. [PMID: 17318645 DOI: 10.1007/s00424-007-0221-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Revised: 12/06/2006] [Accepted: 01/25/2007] [Indexed: 10/23/2022]
Abstract
We previously demonstrated that Ca(2+) sensitization has an essential role for carbachol-induced contraction in the longitudinal muscle of the rat distal colon. In the present study, we extended these studies to clarify the role of Ca(2+) sensitization in contraction induced by the activation of muscarinic receptors in the circular muscle of the rat distal colon. Carbachol induced a rapid phasic contraction followed by a sustained contraction that was significantly lower than the phasic and was superimposed with the rhythmic contractions. The extent of increase in intracellular Ca(2+) concentration that was measured simultaneously with tension recording was dissociated from the phasic contraction, whereas it exhibited to a similar extent as sustained contraction. In alpha-toxin-permeabilized preparations, Ca(2+) induced contraction comprising a rapid phasic and a subsequent low sustained component. After Ca(2+)-induced sustained contraction reached a constant level, guanosine triphosphate (GTP) addition resulted in the enhancement of contractile force in a concentration-dependent manner. Carbachol in the presence of GTP caused a further minimal increase in tension (Ca(2+) sensitization). Chelerythrine, a protein kinase C (PKC) inhibitor, inhibited carbachol-induced Ca(2+) sensitization but not GTP-induced Ca(2+) sensitization. In contrast, Y-27632, a Rho kinase inhibitor, inhibited GTP-induced Ca(2+) sensitization but not that induced by carbachol. Phorbol 12,13-dibutyrate, a PKC activator, increased the sustained contraction. These results suggest that the activation of muscarinic receptor with carbachol induces Ca(2+) sensitization via activation of PKC, but this action is minor in the circular muscle of the rat distal colon as a result of limited coupling between muscarinic receptors and Ca(2+) sensitization via the PKC pathway.
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Affiliation(s)
- Tadayoshi Takeuchi
- Laboratory of Veterinary Pharmacology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
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Patten GS, Adams MJ, Dallimore JA, Abeywardena MY. Depressed prostanoid-induced contractility of the gut in spontaneously hypertensive rats (SHR) is not affected by the level of dietary fat. J Nutr 2004; 134:2924-9. [PMID: 15514253 DOI: 10.1093/jn/134.11.2924] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Dietary saturated fat (SF) has adverse effects on cardiac and vascular smooth muscle (VSM) contractility. Furthermore, VSM of spontaneously hypertensive rats (SHR) is overreactive to various biological stimuli. The aim of this study was to investigate the effects of increasing dietary fat as lard on gut contractility in SHR. Control Wistar-Kyoto (WKY) rats and SHR (13 wk old) were fed for 12 wk a diet containing 3% sunflower oil [low fat (LF), 3% total fat] or diets supplemented with 7% lard [medium fat (MF), 10% total fat] or 27% lard [high fat (HF), 30% total fat]. For ileal and colonic tissues (WKY and SHR), there was a lower total phospholipid PUFA (n-6)/(n-3) ratio with increased dietary SF (P < 0.003). For WKY, increasing SF led to lower levels of the major SCFA and lower total SCFA levels in cecal digesta (P < 0.01). This trend was evident in SHR but significant only for butyrate (P < 0.01). Contractility responses were unaltered in ileum. In colon, there was a change of sensitivity (50% effective concentration) to angiotensin II in WKY (P < 0.05) due to increased SF and a change of sensitivity to prostaglandin (PG)E(2) and carbachol in SHR (P < 0.05). When the 3 dietary groups were combined, there was lower sensitivity (P < 0.01) and lower maximal contraction (P < 0.05) in ileum and lower maximal contraction in colon of SHR in response to PGF(2alpha) (P < 0.05) and PGE(2) (P < 0.01) compared with WKY. Unlike (n-3) PUFA, dietary SF had little overall effect on gut contractility. However, this is the first report of a defect in PG responsiveness from gut tissue from hypertensive rats.
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Affiliation(s)
- Glen S Patten
- CSIRO Health Sciences & Nutrition, Adelaide, South Australia 5000, Australia.
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Kushida M, Takeuchi T, Fujita A, Hata F. Dependence of Ca2+-induced contraction on ATP in alpha-toxin-permeabilized preparations of rat femoral artery. J Pharmacol Sci 2004; 93:171-9. [PMID: 14578585 DOI: 10.1254/jphs.93.171] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Effects of various concentrations of ATP on Ca(2+)-induced contraction were studied in alpha-toxin-permeabilized preparations obtained from the rat femoral artery. The contractile magnitude was highest in the presence of 1 mM ATP and decreased with both increasing and decreasing the concentration, suggesting the presence of an optimum ATP concentration in inducing contraction. The magnitude of the contractions in various concentrations of ATP correlated with the extent of the phosphorylated myosin light chain (MLC). The rate of contractions in the presence of 1 mM ATP under an inhibition of MLC phosphatase was faster than in the presence of 4 mM ATP, suggesting that the increased phosphorylation of MLC at 1 mM ATP results from an increased activity of MLC kinase. On the other hand, MLC phosphatase activity appeared unchanged, because the rates of relaxations under the inhibition of MLC kinase were not different in the presence of either 1 or 4 mM ATP. The high sensitivity to 1 mM ATP was absent in the preparations that were permeabilized with beta-escin or Triton X-100, suggesting the existence of an intracellular factor required for the increased activity of MLC kinase to ATP in the alpha-toxin-permeabilized preparations of the rat femoral artery.
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Affiliation(s)
- Masahiko Kushida
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, Osaka Prefecture University, Sakai, Japan
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Takeuchi T, Kushida M, Hirayama N, Kitayama M, Fujita A, Hata F. Mechanisms involved in carbachol-induced Ca(2+) sensitization of contractile elements in rat proximal and distal colon. Br J Pharmacol 2004; 142:657-66. [PMID: 15159278 PMCID: PMC1575042 DOI: 10.1038/sj.bjp.0705820] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
1. Mechanisms involved in Ca(2+) sensitization of contractile elements induced by the activation of muscarinic receptors in membrane-permeabilized preparations of the rat proximal and distal colon were studied. 2. In alpha-toxin-permeabilized preparations from the rat proximal and distal colon, Ca(2+) induced a rapid phasic and subsequent tonic component. After Ca(2+)-induced contraction reached a plateau, guanosine 5'-triphosphate (GTP) and carbachol (CCh) in the presence of GTP further contracted preparations of both the proximal and distal colon (Ca(2+) sensitization). Y-27632, a rho-kinase inhibitor, inhibited GTP plus CCh-induced Ca(2+) sensitization more significantly in the proximal colon than in the distal colon. 3. Y-27632 at 10 microm had no effect on Ca(2+)-induced contraction or slightly inhibited phorbol-12,13-dibutyrate-induced Ca(2+) sensitization in either proximal or distal colon. Chelerythrine, a protein kinase C inhibitor, inhibited GTP plus CCh-induced Ca(2+) sensitization in the distal colon, but not in the proximal colon. The component of Ca(2+) sensitization that persisted after the chelerythrine treatment was completely inhibited by Y-27632. 4. In beta-escin-permeabilized preparations of the proximal colon, C3 exoenzyme completely inhibited GTP plus CCh-induced Ca(2+) sensitization, but PKC(19-31) did not. In the distal colon, C3 exoenzyme abolished GTP-induced Ca(2+) sensitization. It inhibited CCh-induced sensitization by 50 % and the remaining component was inhibited by PKC(19-31). 5. These results suggest that both protein kinase C and rho pathways in parallel mediate the Ca(2+) sensitization coupled to activation of muscarinic receptors in the rat distal colon, whereas the rho pathway alone mediates this action in the proximal colon.
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Affiliation(s)
- Tadayoshi Takeuchi
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai Osaka 599-8531, Japan.
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Takeuchi T, Kushida M, Kitayama M, Fujita A, Hata F. Origin of ATP for Ca2+-induced contraction in the guinea-pig femoral artery. Naunyn Schmiedebergs Arch Pharmacol 2004; 369:350-7. [PMID: 14730418 DOI: 10.1007/s00210-003-0861-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2003] [Accepted: 12/04/2003] [Indexed: 10/26/2022]
Abstract
Previously, we have described differences between the rat proximal colon and femoral artery with respect to the role of ATP newly synthesized by creatine kinase. In the present study the role of newly synthesized ATP was studied in the guinea-pig femoral artery to examine species differences. In the alpha-toxin-permeabilized preparation of the guinea-pig femoral artery, the rapid Ca(2+)-induced contraction was suppressed when creatine kinase activity was inhibited. The contraction was restored completely by treatment with NaN(3), an inhibitor of ecto-ATPase, the enzyme that breaks down exogenous ATP. Thus, ATP newly synthesized by creatine kinase may have no role in contraction of the guinea-pig femoral artery. This is in marked contrast to the rat femoral artery, in which Ca(2+)-induced contractions are almost completely inhibited by inhibition of creatine kinase activity but only partly restored by NaN(3). To characterize the difference between the guinea-pig and rat tissue, the origin of ATP required for contraction was determined in intact preparations. Monoiodoacetic acid, an inhibitor of glycolysis, inhibited the high K(+)-induced contraction in the guinea-pig femoral artery more potently than in the rat tissue. In contrast, an inhibitor of mitochondrial respiration, carbonylcyanide p-(trifluoromethoxy)phenylhydrazone (FCCP), inhibited contraction in femoral arteries from rats, but not from guinea-pigs. These results suggest that contraction in the rat femoral artery is dependent largely on oxidative phosphorylation, while contraction in the guinea-pig tissue is dependent only on glycolysis. Because oxidative phosphorylation generates ATP and phosphocreatine, while glycolysis generates only ATP, the strong dependence of the contraction of the rat femoral artery on the oxidative phosphorylation is consistent with its dependence on ATP newly synthesized by creatine kinase from ADP and phosphocreatine, as previously shown. Thus, it is proposed that ATP, newly synthesized by creatine kinase, in addition to ATP generated by oxidative phosphorylation, is utilized for contraction in the rat femoral artery, while glycolysis produces sufficient ATP for contraction in the guinea-pig femoral artery.
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Affiliation(s)
- Tadayoshi Takeuchi
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, Osaka Prefecture University, 599-8531 Sakai, Japan.
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Takeuchi T, Fujita A, Kushida M, Hata F. The site where newly synthesized ATP is necessary for tension development in alpha-toxin permeabilized preparations of rat proximal colon. J Pharmacol Sci 2003; 91:277-84. [PMID: 12719656 DOI: 10.1254/jphs.91.277] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Since it was suggested in our previous study that ATP newly synthesized from ADP and phosphocreatine (PCr) by creatine kinase had an important role in Ca2+-induced phasic contraction in alpha-toxin permeabilized smooth muscle of rat proximal colon, we studied the role of newly synthesized ATP on myosin ATPase activity, by assessing a rate of force development as an index of myosin ATPase activity. The alpha-toxin-permeabilized preparations were thiophosphorylated by treatment with ATPgammaS. After the thiophosphorylation, the contraction induced by ATP plus PCr in the absence of Ca2+ reached the maximum at 30 s. When PCr was omitted from the bathing solution, the initial rate of the contraction was significantly slower, while the level of myosin light chain thiophosphorylation remained unchanged. An inhibitor of creatine kinase slowed the initial contractile rate to a rate similar to that induced by ATP alone. ADPbetaS had no effect on ATP plus PCr-induced contraction, suggesting that accumulation of ADP does not affect the initial rate of the contraction. PCr alone did not contract the thiophosphorylated-preparations. However, in the presence of ADP, PCr induced contraction at the initial rate which was slower than that induced by ATP plus PCr. These results indicate that newly synthesized ATP together with preexisting ATP is utilized as a substrate for myosin ATPase.
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Affiliation(s)
- Tadayoshi Takeuchi
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Science, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan.
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