Ca2+ compartments in saponin-skinned cultured vascular smooth muscle cells.

Yamamoto, Hiromichi; Breemen, C. van

doi:10.1085/jgp.87.3.369

Cited by 42 publications

(21 citation statements)

References 39 publications

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“…Ca uptake proceeds with a rate coefficient of 0.038 min-l (time constant = 26.32 min). The rate coefficient for the slow component is similar to the 0.03 min-' reported for diffusion of Ca from the SR of saponin skinned smooth muscle cell cultures, which have a different extracellular Ca compartment (Yamamoto and van Breemen, 1986). …”

Section: Effect Of Ruthenium Red Rr Inhibits Ca-inducedsupporting

confidence: 81%

Calcium transport by sarcoplasmic reticulum of vascular smooth muscle: I. MgATP‐dependent and MgATP‐independent calcium uptake

Stout

1991

Journal Cellular Physiology

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The components of 45calcium (Ca) uptake were studied in saponin skinned rat caudal artery. The steady-state Ca content increased when the free Ca concentration was varied from 10(-8) to 10(-4) M but was reduced by azide when the free Ca concentration exceeded 3.1 microM. The azide sensitivity and low affinity for Ca were consistent with functional mitochondria. The azide-insensitive component consisted of a small bound and a larger releasable Ca fraction. After skinning in Triton X-100, approximately 4 mumol Ca/kg wet tissue remained, which represented a tightly bound but slowly exchangeable Ca pool. The Ca content was independent of the free Ca concentration and MgATP, and it was not released with A-23187 or Ca. The Ca content of the larger fraction was a higher order function of the free Ca concentration and was released with A-23187, indicating it resided within a membrane-bounded structure. Ca uptake by the releasable fraction was increased by oxalate, MgATP, phosphocreatine, temperature, phosphate, and ruthenium red and represents Ca sequestered by the sarcoplasmic reticulum (SR) with little contribution from other Ca binding or storage sites. It is described by the coefficients Umax = 96.94 mumol/kg wet tissue, K1/2 = 0.75 microM, and Hill coefficient = 1.70. The SR in this preparation regulates cytosolic Ca concentrations under physiological conditions and can accumulate Ca by MgATP-dependent and MgATP-independent process. The larger, MgATP-dependent Ca uptake is described by the coefficients Umax = 72.87 mumol/kg wet tissue, K1/2 = 0.8 microM, and Hill coefficient = 2.09 and is consistent with Ca sequestered by the Ca-transport ATPase of smooth muscle SR. The smaller, MgATP-independent uptake is described by the coefficients Umax = 24.14 mumol/kg wet tissue, K1/2 = 0.56 microM, and Hill coefficient = 1.01 and represents Ca sequestered by an unidentified mechanism or by a subpopulation of SR.

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Section: Effect Of Ruthenium Red Rr Inhibits Ca-inducedsupporting

confidence: 81%

Calcium transport by sarcoplasmic reticulum of vascular smooth muscle: I. MgATP‐dependent and MgATP‐independent calcium uptake

Stout

1991

Journal Cellular Physiology

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“…We have demonstrated that cGMP increases Ca 2+ uptake in skinned primary cultured rat aortic smooth The store into which Ca 2+ uptake occurs in the skinned vascular smooth muscle is identified as SR by a number of criteria: 80% of the uptake is dependent on extracellularly supplied MgATP, indicating that the bulk of the uptake uses an energy-dependent process such as the Ca 2+ pump of the SR; uptake was performed at ambient 1 p,M Ca 2+ , a concentration too low for mitochondrial uptake to occur 13 ; and lastly, 97% of this store has been shown to be releasable by IP 3 .…”

Section: Discussionmentioning

confidence: 99%

“…13 Aortae from male Wistar rats (200-250 g) were stripped of advent it ia and endothelium after treatment with collagenase (type I) and elastase (type I). A second incubation in collagenase and elastase yielded single cells and cell clumps that were inoculated with equal density (2 x 10 3 cells/ ml) on 35-mm diameter plastic dishes containing Dulbecco's Modified Eagle Medium supplemented with 10% fetal bovine serum.…”

Section: Smooth Muscle Culturementioning

confidence: 99%

Cyclic guanosine monophosphate-enhanced sequestration of Ca2+ by sarcoplasmic reticulum in vascular smooth muscle.

Twort

Breemen

1988

Circulation Research

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171

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The purpose of this study was to investigate the effects of the intracellular messenger cyclic GMP (cGMP) on sequestration of cytosolic calcium (Ca 1 Stimulation of particulate and soluble guanylate cyclase elevates cytosolic cGMP during the relaxation produced both by endogenous vasodilators (endothelium-derived relaxing factor 2 -3 and atrial natriuretic factor 4 ) and by the nitric oxide-producing drugs (nitroglycerine, nitroprusside). 5 The relaxation occurring with cGMP results from a lowering of the cytosolic concentration of calcium ions (Ca 2+ ). 6 ' 7 This is thought to result predominantly from stimulation of the plasmalemmal Ca 2+ -extrusion ATPase. 8 - 9 An additional means of reducing cytosolic Ca 2+ in vascular smooth muscle is the sequestration of Ca 2+ into an intracellular store, the sarcoplasmic reticulum (SR).10 Although stimulation of SR Ca 2+ uptake is recognized for cyclic AMP-dependent relaxation of vascular smooth muscle, 8 a similar effect for cGMP has yet to be demonstrated. This results partly from the difficulty in experimentally isolating the effects of cGMP on Ca 2+ transport at the SR from those at the plasmalemma. However, the recently described technique of chemical skinning of the plasmalemma by saponin has enabled the investigation of the function of the SR in vascular smooth muscle." Saponin forms micellar complexes Received September 9, 1987; accepted December 11, 1987. with cholesterol, a major component of the plasmalemma. This renders the plasmalemma permeable, while not affecting the membranes of the intracellular organelles, which have a lower cholesterol content. 12We have used this technique to investigate the role of cGMP on SR Ca 2+ transport in primary cultures of rat aortic smooth muscle. We have investigated the effect of cGMP on Ca 2+ uptake by the SR and also on the release of Ca 2+ by the SR in response to inositol 1,4,5-trisphosphate (IP 3 ) and caffeine.

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“…5). Previous work (Itoh et al 1992) (Ashida & Blaustein, 1987) or a minor role (Mulvany, Aalkjer & Petersen, 1984;Ganitkevich & Isenberg, 1993 (Yamamoto & van Breemen, 1986). Finally, this component may simply represent incomplete inhibition of the Ca2+-ATPase.…”

Section: Agonist-evoked Increases In [Ca2+]imentioning

confidence: 95%

Factors controlling changes in intracellular Ca2+ concentration produced by noradrenaline in rat mesenteric artery smooth muscle cells.

Baró

Eisner

1995

The Journal of Physiology

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1. The intracellular Ca2+ concentration ([Ca2+]1) was measured in mesenteric artery smooth muscle cells using the fluorescent indicator indo-1. 6. We conclude that the three major factors responsible for removing Ca2+ ions from the cytoplasm are: (i) a caffeine-and noradrenaline-sensitive store (43%), (ii) a caffeinesensitive but noradrenaline-insensitive store (36 %), and (iii) a sarcolemmal Ca2+-ATPase (16 %). Finally, a 5 % contribution remains to be accounted for.

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Ca2+ compartments in saponin-skinned cultured vascular smooth muscle cells.

Abstract: A method for saponin skinning of primary cultured rat aortic smooth muscle cells was established .

Cited by 42 publications

References 39 publications

Calcium transport by sarcoplasmic reticulum of vascular smooth muscle: I. MgATP‐dependent and MgATP‐independent calcium uptake

Calcium transport by sarcoplasmic reticulum of vascular smooth muscle: I. MgATP‐dependent and MgATP‐independent calcium uptake

Cyclic guanosine monophosphate-enhanced sequestration of Ca2+ by sarcoplasmic reticulum in vascular smooth muscle.

Factors controlling changes in intracellular Ca2+ concentration produced by noradrenaline in rat mesenteric artery smooth muscle cells.

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