Inhibitory action of norepinephrine on sodium transport in vascular smooth muscle cells in culture

Tuck, Michael L.; Hannaert, Patrick; Jeanclos, Elisabeth; Russo‐Marie, Françoise; Garay, Ricardo P.

doi:10.1007/bf00594179

Cited by 3 publications

(1 citation statement)

References 22 publications

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“…The inhibition of Na + -K + -ATPase is related to enhancement of vascular contractility [17,18]. Moreover, data supporting the inhibitory effects of vasoconstrictors on the Na + -K + -ATPase activity have been reported [19]. In view of the multiple vascular actions of ET-1, changes in ion transport systems are also involved in the contractile effect of this peptide.…”

Section: Introductionmentioning

confidence: 94%

Mechanisms Underlying the Contractile Response to Endothelin-1 in the Rat Renal Artery

Callera¹,

Bendhack²

2003

Pharmacology

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We assessed the functional response and the mechanisms following receptor stimulation of endothelin-1 (ET-1) in the rat renal artery. In this study, isometric tension was recorded in renal artery rings without endothelium. Cumulative application of ET-1 from 0.1 to 100 nmol/l induced a sustained concentration-dependent contraction in the renal artery. Submaximal contraction induced by 10 nmol/l ET-1 in 2.5 mmol/l Ca²⁺ and in the absence of inhibitors was used as control response (100%). The relative contribution of different sources of Ca²⁺ in ET-1-induced contraction was evaluated. The contractile response to 10 nmol/l ET-1 in 2.5 mmol/l Ca²⁺(1.2 ± 0.2 g) was significantly inhibited either in Ca²⁺-free solution containing 100 µmol/l ethylene glycol bis-(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (0.6 ± 0.1 g) or after depletion of intracellular Ca²⁺ stores (0.62 ± 0.05 g). The contribution of phospholipase C and protein kinase C was evaluated by using their inhibitors 2-nitro-4-carboxyphenyl N,N-diphenylcarbamate (NCDC) and [1-(5-isoquinolinesulfonyl)-2-methylpiperazine] (H-7), respectively. The contractile response to 10 nmol/l ET-1 was inhibited by 10 µmol/l NCDC (to 80 ± 6%) and 30 µmol/l H-7 (to 76.6 ± 6.5%). We found that 1 µmol/l nifedipine inhibited the ET-1-induced contraction (to 48.7 ± 6.9%), indicating the contribution of Ca²⁺ influx through voltage-gated L-type Ca²⁺ channels to this response. Further, the inhibitory effect of nifedipine was to a greater extent as compared with NCDC or H-7. Additive inhibition of ET-1-induced contraction was not observed in the presence of both nifedipine and NCDC. We also evaluated the role of the ionic transport system in the ET-1-induced response by using 20 nmol/l 5-(N-ethyl-N-isopropyl)-amiloride (EIPA), an inhibitor of Na⁺-H⁺ exchange, or 100 µmol/l ouabain, an inhibitor of Na⁺-K⁺-ATPase. The response to ET-1 was decreased by both EIPA (to 61.6 ± 8.4%) and ouabain (to 62.1 ± 8.6%). The contribution of Na⁺-Ca²⁺ exchange to ouabain action was tested using the inhibitor dimethyl amiloride HCl (10 µmol/l). The decrease in ET-1-induced contraction by the combination of ouabain and dimethyl amiloride HCl was similar to that observed with ouabain alone. In view of these observations, both extra- and intracellular sources of Ca²⁺ contribute to the contractile response induced by ET-1 in the renal artery. Our findings also revealed the importance of Ca²⁺ influx through voltage-gated L-type Ca²⁺ channels in mediating contraction to ET-1 in the renal artery, whereas a minor role of phospholipase C and protein kinase C was observed. Na⁺-H⁺ exchange and Na⁺-K⁺-ATPase also play a role in the ET-1-induced contraction in renal artery. Moreover, the contribution of Na⁺-K⁺-ATPase in ET-1 contraction is not an Na⁺-Ca²⁺

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Section: Introductionmentioning

confidence: 94%

Mechanisms Underlying the Contractile Response to Endothelin-1 in the Rat Renal Artery

Callera¹,

Bendhack²

2003

Pharmacology

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Action of azelastine on intracellular Ca2+ in cultured airway smooth muscle

Senn

Jeanclos

Garay

1991

European Journal of Pharmacology

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Regulation of Na+ and K+ contents in rat thymocytes

Senn

Garay

1989

American Journal of Physiology-Cell Physiology

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A modified nystatin technique allowed the investigation of the initial rate of Na+ efflux as a function of internal Na+ content under steady-state conditions in rat thymocytes. This kinetic study showed that 1) ouabain-sensitive Na+ efflux as a function of internal Na+ can be adjusted by a three-sites kinetic model, with a maximal pump rate of 581 +/- 79 mmol.l cells-1.h-1 and an apparent dissociation constant for internal Na+ of 10.0 +/- 1.0 mmol/l cells (mean +/- SE of 3 experiments), 2) bumetanide-sensitive Na+ efflux was extremely low compared with the pump efflux (approximately 1%), and 3) ouabain- and bumetanide-resistant Na+ efflux was almost a linear function of internal Na+ content (as expected for a Na+ leak). This "all-pump" mechanism of thymocyte Na+ regulation was confirmed by non-steady-state experiments showing that 1) ouabain induced a rapid net Na+ gain and K+ depletion in fresh thymocytes and completely blocked the recovery of normal cation contents in Na+-loaded-K+-depleted thymocytes, and 2) bumetanide was unable to modify thymocyte Na+ and K+ contents. Na+ extrusion by Na+-loaded thymocytes was unaffected by prostaglandin E2, isoproterenol, or platelet-aggregating factor (PAF) and was slightly impaired in the adult spontaneously hypertensive rat of the Okamoto strain (10% lower rate constant for net Na+ extrusion, P less than 0.05). Concerning cell Na+ regulation, our results do not support the concept that rat thymocytes are more representative of vascular cells than enucleated erythrocytes.

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Inhibitory action of norepinephrine on sodium transport in vascular smooth muscle cells in culture

Cited by 3 publications

References 22 publications

Mechanisms Underlying the Contractile Response to Endothelin-1 in the Rat Renal Artery

Mechanisms Underlying the Contractile Response to Endothelin-1 in the Rat Renal Artery

Action of azelastine on intracellular Ca2+ in cultured airway smooth muscle

Regulation of Na+ and K+ contents in rat thymocytes

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