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Voltage-gated potassium currents in rat vas deferens smooth muscle cells.
Pflugers Arch. 2003 Jun; 446(3):380-6.PA

Abstract

Voltage-gated components of the outward current in single smooth muscle cells isolated from the epididymal part of the rat vas deferens were studied using amphotericin B perforated patch-clamp techniques. The complex kinetics of the net outward current elicited by positive voltage steps from -80 mV to +40 mV suggested the presence of several components. Bath application of 200 nM charybdotoxin, a potent blocker of large-conductance, Ca(2+)-dependent K(+) channels (BK(Ca)), reduced the current amplitude significantly. When BK(Ca) channels were suppressed, fast-inactivating (I(K,f)) and delayed rectifying (I(K,dr)) components of the outward current were identified. I(K,f) was characterized by fast kinetics of current decay, negative steady-state activation and inactivation dependencies and sensitivity to 4-aminopyridine with an apparent K(d) of 0.32 mM, properties similar to those of the A-type K(+) current. In contrast, I(K,dr) activated and inactivated at more positive potentials. The time constant of activation of I(K,dr) was voltage dependent with an e-fold decrease per 21 mV depolarization. I(K,dr) was inhibited by clofilium, a blocker of voltage-gated K(+) channels, with an IC(50) of 12 micro M and was not blocked by 5 mM 4-aminopyridine. The possible significance of the voltage-gated currents is discussed.

Authors+Show Affiliations

Nerve-Muscle Physiology Department, Bogomoletz Institute of Physiology, Bogomoletz Street 4, Kiev-24, Ukraine.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

12684789

Citation

Harhun, Maksym I., et al. "Voltage-gated Potassium Currents in Rat Vas Deferens Smooth Muscle Cells." Pflugers Archiv : European Journal of Physiology, vol. 446, no. 3, 2003, pp. 380-6.
Harhun MI, Jurkiewicz A, Jurkiewicz NH, et al. Voltage-gated potassium currents in rat vas deferens smooth muscle cells. Pflugers Arch. 2003;446(3):380-6.
Harhun, M. I., Jurkiewicz, A., Jurkiewicz, N. H., Kryshtal, D. O., Shuba, M. F., & Vladimirova, I. A. (2003). Voltage-gated potassium currents in rat vas deferens smooth muscle cells. Pflugers Archiv : European Journal of Physiology, 446(3), 380-6.
Harhun MI, et al. Voltage-gated Potassium Currents in Rat Vas Deferens Smooth Muscle Cells. Pflugers Arch. 2003;446(3):380-6. PubMed PMID: 12684789.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Voltage-gated potassium currents in rat vas deferens smooth muscle cells. AU - Harhun,Maksym I, AU - Jurkiewicz,Aron, AU - Jurkiewicz,Neide H, AU - Kryshtal,Dmytro O, AU - Shuba,Michael F, AU - Vladimirova,Irina A, Y1 - 2003/04/04/ PY - 2002/08/20/received PY - 2002/10/20/accepted PY - 2003/4/10/pubmed PY - 2004/3/6/medline PY - 2003/4/10/entrez SP - 380 EP - 6 JF - Pflugers Archiv : European journal of physiology JO - Pflugers Arch VL - 446 IS - 3 N2 - Voltage-gated components of the outward current in single smooth muscle cells isolated from the epididymal part of the rat vas deferens were studied using amphotericin B perforated patch-clamp techniques. The complex kinetics of the net outward current elicited by positive voltage steps from -80 mV to +40 mV suggested the presence of several components. Bath application of 200 nM charybdotoxin, a potent blocker of large-conductance, Ca(2+)-dependent K(+) channels (BK(Ca)), reduced the current amplitude significantly. When BK(Ca) channels were suppressed, fast-inactivating (I(K,f)) and delayed rectifying (I(K,dr)) components of the outward current were identified. I(K,f) was characterized by fast kinetics of current decay, negative steady-state activation and inactivation dependencies and sensitivity to 4-aminopyridine with an apparent K(d) of 0.32 mM, properties similar to those of the A-type K(+) current. In contrast, I(K,dr) activated and inactivated at more positive potentials. The time constant of activation of I(K,dr) was voltage dependent with an e-fold decrease per 21 mV depolarization. I(K,dr) was inhibited by clofilium, a blocker of voltage-gated K(+) channels, with an IC(50) of 12 micro M and was not blocked by 5 mM 4-aminopyridine. The possible significance of the voltage-gated currents is discussed. SN - 0031-6768 UR - https://www.unboundmedicine.com/medline/citation/12684789/Voltage_gated_potassium_currents_in_rat_vas_deferens_smooth_muscle_cells_ L2 - https://dx.doi.org/10.1007/s00424-002-0986-7 DB - PRIME DP - Unbound Medicine ER -