Action of the Na+ ionophore monensin on vascular smooth muscle of guinea-pig aorta

Ozaki, Hiroshi; Kishimoto, Tadashi; Chihara, Shu; Umeno, Hiroshi; Urakawa, Norimoto

doi:10.1016/0014-2999(84)90006-2

Cited by 4 publications

(1 citation statement)

References 16 publications

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“…In vascular smooth muscles, such as the porcine carotid artery [20] or guinea pig aorta [24], removal of glucose from the PSS did not affect high K + -induced contraction. Moreover, hypoxia did not affect high K + -induced contraction in the rabbit aorta [23] or porcine carotid artery [20].…”

Section: Discussionmentioning

confidence: 99%

Key Role of Glycogen Storage in High K<sup>+</sup>-Induced Contraction of the Smooth Muscles of the Bovine Trachea

Kaneda

Fujieda

Eto

et al. 2012

The Journal of Veterinary Medical Science

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ABSTRACT. To elucidate the role of glycogen in the contraction of tracheal smooth muscle, we investigated the changes in the glycogen contents of the bovine trachea during contractions induced by high K + and hypoxia (achieved by bubbling N 2 instead of O 2 ), either in a glucose-free condition or in the presence of iodoacetic acid (IAA), an inhibitor of glycolysis. Hyperosmotic addition of 65 mM KCl (H-65 K + ) induced a sustained contraction. A glucose-free condition did not affect H-65 K + -induced contraction. However, hypoxia slightly inhibited the contraction, and glucose-free PSS with hypoxia or IAA remarkably inhibited the H-65 K + -induced contraction. H-65 K + induced a sustained increase in reduced pyridine nucleotide (PNred) fluorescence, representing glycolysis activity. Hypoxia alone slightly enhanced PNred fluorescence, and when combined with a glucose-free condition, it remarkably enhanced the H-65 K + -induced PNred fluorescence. IAA inhibited PNred fluorescence. In the presence of H-65 K + , a glucose-free condition, hypoxia and the combination of glucose-free PSS and hypoxia decreased the glycogen contents. However, IAA had no effect on glycogen contents. Although hypoxia or glucose-free PSS did not affect PCr and ATP contents, the combination of hypoxia and glucose-free PSS or IAA induced a gradual decrease of PCr content. In conclusion, we suggest that endogenous glycogen was utilized to increase the activity of glycolysis for maintaining high K + -induced contraction of the bovine trachea in the glucose -free and/or hypoxic condition.

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Section: Discussionmentioning

confidence: 99%

Key Role of Glycogen Storage in High K<sup>+</sup>-Induced Contraction of the Smooth Muscles of the Bovine Trachea

Kaneda

Fujieda

Eto

et al. 2012

The Journal of Veterinary Medical Science

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Heterogeneity of the effects of monensin on two types of contractions evoked by inhibition of Na+-K+ ATPase in the guinea-pig vas deferens

Katsuragi

Kuratomi

Tokunaga

et al. 1989

European Journal of Pharmacology

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Ca dependence of Na influx during treatment of rabbit aorta with NE and high K solutions

Aaronson

Jones

1988

American Journal of Physiology-Cell Physiology

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Cellular influx of 24Na was measured in isolated rabbit aorta during stimulation with 10 microM norepinephrine (NE) or depolarization with 80 mM K solution, using a pulse-labeling, cold-wash technique. NE caused a two- to threefold increase in Na influx; a smaller but significant increase was also observed in depolarized tissues. Basal and NE-induced fluxes at 1 min were significantly increased by a 20-min preincubation in a Ca-free solution containing 2 mM EGTA; elevation of [Mg] in this solution reduced these effects. The high K-induced influx was prevented by a combination of low Ca (30 microns) and elevated Mg (10 mM). The Ca agonist, BAY-K 8644, increased 24Na influx. The Ca antagonist, diltiazem, inhibited the depolarization-stimulated 24Na influx in a concentration-dependent manner, but was less effective in blocking the response to NE. Extension of the preincubation in NE plus Ca-free medium from 30 s to 15 min decreased the influx response and contraction. After exposure to NE in Ca-free solution, 24Na influx remained elevated 10 min after washing out NE in the continued absence of Ca. A second exposure to NE at that time did not increase influx. We propose that a component of 24Na influx during excitation depends directly on a rise in intracellular [Ca]. The role of an indirect effect of [Ca] on metabolic H+ production with subsequent stimulation of the Na+-H+ exchange may also be a factor.

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Action of the Na+ ionophore monensin on vascular smooth muscle of guinea-pig aorta

Cited by 4 publications

References 16 publications

Key Role of Glycogen Storage in High K<sup>+</sup>-Induced Contraction of the Smooth Muscles of the Bovine Trachea

Key Role of Glycogen Storage in High K<sup>+</sup>-Induced Contraction of the Smooth Muscles of the Bovine Trachea

Heterogeneity of the effects of monensin on two types of contractions evoked by inhibition of Na+-K+ ATPase in the guinea-pig vas deferens

Ca dependence of Na influx during treatment of rabbit aorta with NE and high K solutions

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