ArticleBritish journal of pharmacology2000
4-aminopyridine affects rat arterial smooth muscle BK(Ca) currents by changing intracellular pH.
Article in British journal of pharmacology, 2000. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers.
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Who cites it
9 citing papers in PubMed, 21 citations in OpenAlex.
- Remodeling of Arterial Tone Regulation in Postnatal Development: Focus on Smooth Muscle Cell Potassium Channels.International journal of molecular sciences · 2021Review
- 4-Aminopyridine: a pan voltage-gated potassium channel inhibitor that enhances KBritish journal of pharmacology · 2018Article
- 'Gardos Channelopathy': a variant of hereditary Stomatocytosis with complex molecular regulation.Scientific reports · 2017Article
- Ionic mechanisms underlying tonic and phasic firing behaviors in retinal ganglion cells: a model study.Channels (Austin, Tex.) · 2014Article
- Effects of hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blockers on the proliferation and cell cycle progression of embryonic stem cells.Pflugers Archiv : European journal of physiology · 2011Article
- Vasopressin stimulates action potential firing by protein kinase C-dependent inhibition of KCNQ5 in A7r5 rat aortic smooth muscle cells.American journal of physiology. Heart and circulatory physiology · 2007Article
- (+/-)-Naringenin as large conductance Ca(2+)-activated K+ (BKCa) channel opener in vascular smooth muscle cells.British journal of pharmacology · 2006Article
- Smooth muscle membrane potential modulates endothelium-dependent relaxation of rat basilar artery via myo-endothelial gap junctions.The Journal of physiology · 2002Article
- Block of mouse Slo1 and Slo3 K+ channels by CTX, IbTX, TEA, 4-AP and quinidine.Channels (Austin, Tex.)Article
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Authors and funding
6 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The hypothesis whether or not 4-AP can affect vascular smooth muscle BK(Ca) currents was tested using the patch-clamp technique, pH- and calcium-fluorimetry, and freshly isolated rat arterial smooth muscle cells. Application of 4-AP reversibly inhibited BK(Ca) currents at an intracellular calcium ([Ca](i)) of 250 nM with a half-block of 2. 5 mM at +50 mV. The presence of 2 microM thapsigargin, 10 microM heparin, and 10 microM ryanodine did not alter the effect of 4-AP on BK(Ca) currents at [Ca](i) 250 nM. At [Ca](i)<100 nM 4-AP did not inhibit BK(Ca) currents. Application of 4-AP to the intracellular or extracellular side of excised BK(Ca) channels did not alter channel activity or channel amplitude. Replacement of the pH-sensitive calcium buffer EGTA by the pH-insensitive calcium buffer BAPTA in the intracellular solution turned the 4-AP-induced inhibition of BK(Ca) currents into a stimulation at [Ca](i) 250 nM. Application of 4-AP to single cells increased intracellular pH, which was accompanied by a reduction of [Ca](i) in EGTA-loaded cells and a stable [Ca](i) in BAPTA-loaded cells. Thus, these results suggest that in isolated vascular smooth muscle cells at [Ca](i)>100 nM 4-AP affects BK(Ca) currents via an alteration of intracellular pH.
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