Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Calcium in smooth muscle

Taggart MJ, Wray S 1997 Agonist mobilization of sarcoplasmic reticular calcium in smooth muscle functional coupling to the plasmalemmal Na+/Ca2+ exchanger. Cell Calcium 22 333-341... [Pg.18]

Protein Tyrosine Phosphorylation and Regulation of Intracellular Calcium in Smooth Muscle Cells... [Pg.283]

Fleischmann, B.K., Murray, R.K., and Kotlikoff, M.l. (1994 voltage window for sustained elevation of cytosolic calcium in smooth muscle cells. Proceedings of the National Academy of Sciences of the United States of America, 91 11914-11918. [Pg.185]

Cao JW, Luo HS, Yu BP et al (2001) Effects of berberine on intracellular free calcium in smooth muscle cells of Guinea pig colmi. Digestion 64(3) 179-183... [Pg.4495]

The ETa receptor activates G proteins of the Gq/n and G12/i3 family. The ETB receptor stimulates G proteins of the G and Gq/11 family. In endothelial cells, activation of the ETB receptor stimulates the release of NO and prostacyclin (PGI2) via pertussis toxin-sensitive G proteins. In smooth muscle cells, the activation of ETA receptors leads to an increase of intracellular calcium via pertussis toxin-insensitive G proteins of the Gq/11 family and to an activation of Rho proteins most likely via G proteins of the Gi2/i3 family. Increase of intracellular calcium results in a calmodulin-dependent activation of the myosin light chain kinase (MLCK, Fig. 2). MLCK phosphorylates the 20 kDa myosin light chain (MLC-20), which then stimulates actin-myosin interaction of vascular smooth muscle cells resulting in vasoconstriction. Since activated Rho... [Pg.473]

Jaggar JH, Porter VA, Lederer WJ et al (2000) Calcium sparks in smooth muscle. Am J Physiol Cell Physiol 278 C235-C256... [Pg.1145]

Tropomyosin is thought to lie in the groove formed between the associated actin strands. The sites at which the myosin crossbridges attach are affected by the relationship between tropomyosin and the actin strands. The role of tropomyosin in smooth muscle is completely undefined while in striated muscle it is clearly involved in the activation of contraction. The difference is made clear by the absence from smooth muscle of the protein, troponin, which in striated muscle provides the binding site for the triggering calcium. [Pg.170]

Figure 6. A hypothetical scheme for the control of the number of active crossbridges in smooth muscle. Following the activation of a smooth muscle by an agonist, the concentrations of intermediates along the main route begins to build up transiently. This is shown by the thickened arrows. Also, cAMP is generated which is universally an inhibitor in smooth muscle. Cyclic AMP in turn combines with protein kinase A, which accounts for most of its action. The downstream mechanisms, however, are not well worked out and at least three possibilities are likely in different circumstances. First, protein kinase A is known to catalyze the phosphorylation of MLCK, once phosphorylated MLCK has a relatively lower affinity for Ca-calmodulin so that for a given concentration of Ca-calmodulin, the activation downstream is reduced. The law of mass action predicts that this inhibition should be reversed at high calcium concentrations. Other cAMP inhibitory mechanisms for which there is evidence include interference with the SR Ca storage system, and activation of a MLC phosphatase. Figure 6. A hypothetical scheme for the control of the number of active crossbridges in smooth muscle. Following the activation of a smooth muscle by an agonist, the concentrations of intermediates along the main route begins to build up transiently. This is shown by the thickened arrows. Also, cAMP is generated which is universally an inhibitor in smooth muscle. Cyclic AMP in turn combines with protein kinase A, which accounts for most of its action. The downstream mechanisms, however, are not well worked out and at least three possibilities are likely in different circumstances. First, protein kinase A is known to catalyze the phosphorylation of MLCK, once phosphorylated MLCK has a relatively lower affinity for Ca-calmodulin so that for a given concentration of Ca-calmodulin, the activation downstream is reduced. The law of mass action predicts that this inhibition should be reversed at high calcium concentrations. Other cAMP inhibitory mechanisms for which there is evidence include interference with the SR Ca storage system, and activation of a MLC phosphatase.
In skeletal muscle, calcium binds to troponin and causes the repositioning of tropomyosin. As a result, the myosin-binding sites on the actin become uncovered and crossbridge cycling takes place. Although an increase in cytosolic calcium is also needed in smooth muscle, its role in the mechanism of contraction is very different. Three major steps are involved in smooth muscle contraction ... [Pg.157]

In smooth muscle, myosin crossbridges have less myosin ATPase activity than those of skeletal muscle. As a result, the splitting of ATP that provides energy to "prime" the crossbridges, preparing them to interact with actin, is markedly reduced. Consequently, the rates of crossbridge cycling and tension development are slower. Furthermore, a slower rate of calcium removal causes the muscle to relax more slowly. [Pg.158]

The smooth endoplasmic reticulum calcium pumps (SERCA) found in brain were first identified in sarcoplasmic reticulum. The three isoforms of SERCA are products of separate genes SERCA-1 is expressed in fast-twitch skeletal muscle SERCA-2a in cardiac/slow-twitch muscle SERCA-2b, an alternatively spliced form, is expressed in smooth muscle and non-muscle tissues SERCA-3 is... [Pg.80]

Fig. 4.1. Cellular model illustrating cell types in vascular wall involved in vasorelaxation induced by SERMs. Putative targets of SERMs are indicated within cyan tags. SERMs directly affect L-type VDCC, BK fil subunit in smooth muscle cells, and ER in endothelial cells. L-type VDCC L-type voltage-dependent calcium channel BK calcium-activated large conductance K+ channel PKG protein kinase G eNOS endothelial nitric oxide synthase GC soluble guanylate cyclase cGMP cyclic GM P V electrochemical membrane potential ER estrogen receptor. See text for further details... Fig. 4.1. Cellular model illustrating cell types in vascular wall involved in vasorelaxation induced by SERMs. Putative targets of SERMs are indicated within cyan tags. SERMs directly affect L-type VDCC, BK fil subunit in smooth muscle cells, and ER in endothelial cells. L-type VDCC L-type voltage-dependent calcium channel BK calcium-activated large conductance K+ channel PKG protein kinase G eNOS endothelial nitric oxide synthase GC soluble guanylate cyclase cGMP cyclic GM P V electrochemical membrane potential ER estrogen receptor. See text for further details...
Collier ML, Ji G, Wang Y, Kotlikoff MI 2000 Calcium-induced calcium release in smooth muscle loose coupling between the action potential and calcium release. J Gen Physiol 115 653-662... [Pg.17]

Herrera GM, Nelson MT 2002 SR and membrane currents. In Role of the sarcoplasmic reticulum in smooth muscle. Wiley, Chichester (Novartis Found Symp 246) p 189—207 Sanders KM 2001 Mechanisms of calcium handling in smooth muscles. J Appl Physiol 91 1438-1449... [Pg.17]

Taggart MJ, Wray S 1998 Contribution of sarcoplasmic reticular calcium to smooth muscle contractile activation gestational dependence in isolated rat uterus. J Physiol 511 133—144... [Pg.18]

Carl A, Lee HK, Sanders KM 1996 Regulation of ion channels in smooth muscle by calcium. Am J Physiol 271 C9-C34... [Pg.64]

Voets T, Prenen J, Fleig A et al 2001 CaTl and the calcium-release activated calcium channel manifest distinct pore properties. J Biol Chem 276 47767-47770 Walker RL, Hume JR, Horowitz B 2001 Differential expression and alternative splicing of TRP channel genes in smooth muscles. Am J Physiol 280 0184-0192 Yue L, Peng J-B, Hediger MA, Clapham DE 2001 CaTl manifests the pore properties of the calcium-release-activated calcium channel. Nature 410 705—709... [Pg.76]

Karaki H, Ozaki H, Hori M et al 1997 Calcium movements, distribution, and functions in smooth muscle. Pharmacol Rev 49 157-230... [Pg.89]

Kotlikoff MI, Herrera G, Nelson MT 1999 Calcium permeant ion channels in smooth muscle. Rev Physiol Biochem Pharmacol 134 147-199... [Pg.89]

Bulbring E, T omita T 1969 Effect of calcium, barium and manganese on the action of adrenaline in the smooth muscle of the guinea-pig taenia coli. Proc R Soc Lond B Biol Sci 172 121-136 Marchant JS, Taylor CW 1998 Rapid activation and partial inactivation of inositol trisphosphate receptors by inositol trisphosphate. Biochemistry 37 11524-11533 Somlyo AV, Horiuti K, Trentham DR, Kitazawa T, Somlyo AP 1992 Kinetics of Ca2+ release and contraction induced by photolysis of caged D-myo-inositol 1,4,5-trisphosphate in smooth muscle the effects of heparin, procaine, and adenine nucleotides. J Biol Chem 267 22316-22322... [Pg.107]

Calcium release by ryanodine receptors in smooth muscle... [Pg.108]

See other pages where Calcium in smooth muscle is mentioned: [Pg.118]    [Pg.121]    [Pg.79]    [Pg.79]    [Pg.81]    [Pg.83]    [Pg.85]    [Pg.87]    [Pg.89]    [Pg.91]    [Pg.93]    [Pg.151]    [Pg.325]    [Pg.118]    [Pg.121]    [Pg.79]    [Pg.79]    [Pg.81]    [Pg.83]    [Pg.85]    [Pg.87]    [Pg.89]    [Pg.91]    [Pg.93]    [Pg.151]    [Pg.325]    [Pg.438]    [Pg.48]    [Pg.189]    [Pg.194]    [Pg.195]    [Pg.93]    [Pg.17]    [Pg.63]    [Pg.64]   
See also in sourсe #XX -- [ Pg.570 , Pg.571 ]



SEARCH



In muscle

Muscle calcium

© 2024 chempedia.info