α1-adrenoceptor subtypes mediating the regulation and modulation of Ca2+ sensitization in rabbit thoracic aorta

Satoh, Mitsutoshi; Kojima, Chiemi; Kokubu, Noriko; Takayanagi, Issei

doi:10.1016/0014-2999(94)90423-5

Cited by 15 publications

(7 citation statements)

References 32 publications

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“…This has been supported by the ®nding that the PKC inhibitor H-7 inhibits the enhancement of the Ca 2+ -induced contractions induced by GTP g S and some receptor agonists (Nishimura et al, 1988;Satoh et al, 1994). By contrast, the present study demonstrated that neither calphostin C nor staurosporine did aect GTP g S-induced Ca 2+ sensitization in b-escin-permeabilized smooth muscle of rabbit mesenteric artery, whereas they completely inhibited PDBuinduced Ca 2+ sensitization.…”

Section: Casupporting

confidence: 31%

Tyrosine phosphorylation as a convergent pathway of heterotrimeric G protein‐ and rho protein‐mediated Ca²⁺ sensitization of smooth muscle of rabbit mesenteric artery

Sasaki

Hattori

Tomita

et al. 1998

British J Pharmacology

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1 The aim of this study was to determine whether dierent signal transduction mechanisms underlie the Ca 2+ sensitizing eects of guanosine 5'-O-(3-thiotriphosphate) (GTP g S) and receptor agonists on b-escin-skinned smooth muscle of rabbit mesenteric artery. 2 In the homogenate of the b-escin-skinned arterial strip, C3 exoenzyme of Clostridium botulinum catalyzed the [ 32 P]-ADP-ribosylation of only one protein that had the same molecular mass as the protein detected in Western blots with anti-rho p21 antibody. Pretreatment of preparations with C3 resulted in great inhibition of GTP g S-induced Ca 2+ sensitization, although the eect of GTP g S at higher concentrations (530 mM) was not completely blocked by this treatment. In contrast, the enhancement by phenylephrine and histamine, in the presence of guanosine 5'-triphosphate, of the Ca sensitizing eects of phenylephrine and histamine were also blocked by these tyrosine kinase inhibitors. 5 These results suggest that rho p21 predominantly mediates GTP g S-induced Ca 2+ sensitization of b-escin-skinned smooth muscle of rabbit mesenteric artery, while the Ca 2+ sensitizing actions of heterotrimeric G protein-coupled receptor agonists do not involve this small G protein. However, it seems that tyrosine phosphorylation, but not PKC activation, plays an important role in both of the rho p21 protein-and heterotrimeric G protein-mediated Ca 2+ sensitization mechanisms.

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Section: Casupporting

confidence: 31%

Tyrosine phosphorylation as a convergent pathway of heterotrimeric G protein‐ and rho protein‐mediated Ca²⁺ sensitization of smooth muscle of rabbit mesenteric artery

Sasaki

Hattori

Tomita

et al. 1998

British J Pharmacology

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“…An obvious mechanism for these effects may simply be decreased [Ca 2ϩ ] i responses to bronchonconstrictor agonist, as demonstrated in human ASM cells in our previous study (61) -independent mechanisms (i.e., Ca 2ϩ sensitization) (71). In this regard, agonist stimulation is known to increase myofilament Ca 2ϩ sensitivity (4,6,8,26,63) via the monomeric GTP binding protein, RhoA, and its downstream target, Rho kinase (6,8,26), which phosphorylates and inhibits myosin light chain phosphatase, thus maintaining MLC phosphorylation and contraction. Rho kinase inhibition by fasudil or Y-27632 is known to relax ASM (9,78).…”

Section: Discussionmentioning

confidence: 94%

Caveolin-1 and force regulation in porcine airway smooth muscle

Sathish¹,

Yang²,

Meuchel

et al. 2011

American Journal of Physiology-Lung Cellular and Molecular Phys

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We recently demonstrated the presence of caveolae in human airway smooth muscle (ASM) and the contribution of caveolin-1 to intracellular calcium ([Ca 2ϩ ]i) regulation. In the present study, we tested the hypothesis that caveolin-1 regulates ASM contractility. We examined the role of caveolins in force regulation of porcine ASM under control conditions as well as TNF-␣-induced airway inflammation. In porcine ASM strips, exposure to 10 mM methyl-␤-cyclodextrin (CD) or 5 M of the caveolin-1 specific scaffolding domain inhibitor peptide (CSD) resulted in time-dependent decrease in force responses to 1 M ACh. Overnight exposure to the cytokine TNF-␣ (50 ng/ml) accelerated and increased caveolin-1 expression and enhanced force responses to ACh. Suppression of caveolin-1 with small interfering RNA mimicked the effects of CD or CSD. Regarding mechanisms by which caveolae contribute to contractile changes, inhibition of MAP kinase with 10 M PD98059 did not alter control or TNF-␣-induced increases in force responses to ACh. However, inhibiting RhoA with 100 M fasudil or 10 M Y27632 resulted in significant decreases in force responses, with lesser effects in TNF-␣ exposed samples. Furthermore, Ca 2ϩ sensitivity for force generation was substantially reduced by fasudil or Y27632, an effect even more enhanced in the absence of caveolin-1 signaling. Overall, these results indicate that caveolin-1 is a critical player in enhanced ASM contractility with airway inflammation. caveolae; lung; inflammation; cytokine; MAP kinase; RhoA; small interfering RNA CAVEOLAE, FLASK-SHAPED PLASMA membrane invaginations rich in cholesterol and sphingolipids, express any of three caveolin proteins (caveolin-1, caveolin-2, and/or caveolin-3). By virtue of caveolar expression of agonist receptors, ion channels, and other membrane proteins, as well as the association of caveolins with intracellular proteins, the role of caveolins as organizers and facilitators of signal transduction is now well recognized (12,23,38,62,67,81,82).Multiple studies including our own (16,28,33,61,68,73), have now demonstrated the presence of caveolae and caveolins in airway smooth muscle (ASM

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“…After completion of the Ca 2ϩ dose-response protocol, the arteries were returned to relaxing solution. To test the effects of the selective PKC activator, (Ϫ)-indolactam V (Sigma), on Ca 2ϩ sensitivity, the arteries were exposed to a submaximal concentration of free Ca 2ϩ , which in accordance with previous measurements of Ca 2ϩ -dependent force was approximately the EC 30 . Once the contractile responses to this concentration of Ca 2ϩ had stabilized, graded concentrations of indolactam V (0.03-3 µM) were added.…”

Section: Experimental Protocolsmentioning

confidence: 99%

Regulation of Ca²⁺sensitization by PKC and rho proteins in ovine cerebral arteries: effects of artery size and age

Akopov

Zhang

Pearce

1998

American Journal of Physiology-Heart and Circulatory Physiology

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G protein-regulated Ca2+ sensitivity of vascular contractile proteins plays an important role in cerebrovascular reactivity. The present study examines the intracellular mechanisms that govern G protein-regulated Ca2+ sensitivity in cerebral arteries of different size and age. We studied β-escin-permeabilized segments of common carotid, basilar, and middle cerebral arteries from nonpregnant adult and near-term fetal sheep. Activation of protein kinase C (PKC) by (−)-indolactam V or a phorbol ester produced receptor-independent increases in Ca2+ sensitivity. Such increases were more marked in immature arteries and were inversely correlated with artery size in both mature and immature arteries. However, inhibitors of PKC did not significantly affect increases in Ca2+ sensitivity in responses to either serotonin (5-hydroxytryptamine, 5-HT) or guanosine 5′- O-(3-thiotriphosphate) (GTPγS). Alternatively, deactivation of rho p21, a small G protein associated with Rho kinase, by exotoxin C3 fully prevented increases in Ca2+ sensitivity in responses to 5-HT or GTPγS in both adult and fetal arteries of all types. Neither inhibitors of PKC nor exotoxin C3 altered baseline Ca2+ sensitivity. We conclude that patterns of receptor- and/or G protein-mediated modulation of Ca2+ sensitivity are dependent on an intracellular pathway that involves activation of small G proteins and Rho kinase. In contrast, PKC has little, if any, role in agonist-induced Ca2+ sensitization under the present experimental conditions.

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α1-adrenoceptor subtypes mediating the regulation and modulation of Ca2+ sensitization in rabbit thoracic aorta

Cited by 15 publications

References 32 publications

Tyrosine phosphorylation as a convergent pathway of heterotrimeric G protein‐ and rho protein‐mediated Ca²⁺ sensitization of smooth muscle of rabbit mesenteric artery

Tyrosine phosphorylation as a convergent pathway of heterotrimeric G protein‐ and rho protein‐mediated Ca²⁺ sensitization of smooth muscle of rabbit mesenteric artery

Caveolin-1 and force regulation in porcine airway smooth muscle

Regulation of Ca²⁺sensitization by PKC and rho proteins in ovine cerebral arteries: effects of artery size and age

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α1-adrenoceptor subtypes mediating the regulation and modulation of Ca2+ sensitization in rabbit thoracic aorta

Cited by 15 publications

References 32 publications

Tyrosine phosphorylation as a convergent pathway of heterotrimeric G protein‐ and rho protein‐mediated Ca2+ sensitization of smooth muscle of rabbit mesenteric artery

Tyrosine phosphorylation as a convergent pathway of heterotrimeric G protein‐ and rho protein‐mediated Ca2+ sensitization of smooth muscle of rabbit mesenteric artery

Caveolin-1 and force regulation in porcine airway smooth muscle

Regulation of Ca2+sensitization by PKC and rho proteins in ovine cerebral arteries: effects of artery size and age

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Tyrosine phosphorylation as a convergent pathway of heterotrimeric G protein‐ and rho protein‐mediated Ca²⁺ sensitization of smooth muscle of rabbit mesenteric artery

Tyrosine phosphorylation as a convergent pathway of heterotrimeric G protein‐ and rho protein‐mediated Ca²⁺ sensitization of smooth muscle of rabbit mesenteric artery

Regulation of Ca²⁺sensitization by PKC and rho proteins in ovine cerebral arteries: effects of artery size and age