Type

Journal Article

Authors

Keith D. Thornbury
Noel G McHale
P.F. Keane
I.K. Walsh
Siobhan M. Woolsey
Mark A Hollywood

Subjects

Medicine & Nursing

Topics
steady state prostate cancer type 2 ca l l science smooth muscle cells human cells v v

T- and L-type Ca 2+ currents in freshly dispersed smooth muscle cells from the human proximal urethra (2003)

Abstract The purpose of the present study was to characterise Ca 2+ currents in smooth muscle cells solated from biopsy samples taken from the proximal urethra of patients undergoing surgery for bladder or prostate cancer. Cells were studied at 37°C using the amphotericin B perforated-patch onfiguration of the patch-clamp technique. Currents were recorded using Cs + -rich pipette solutions to block K + currents. Two components of current, with electrophysiological and pharmacological properties typical of T- and L-type Ca 2+ currents, were present in these cells. When steady-state inactivation curves for the L current were fitted with a Boltzmann equation, this yielded a VÎ of _45 ± 5 mV. In contrast, the T current inactivated with a VÎ of _80 ± 3 mV. The L currents were reduced in a concentration-dependent manner by nifedipine (ED50 = 159 ± 54 nM) and Ni 2+ (ED50 = 65 ± 16 mM) but were enhanced when external Ca 2+ was substituted with Ba 2+ . The T current was little affected by TTX, reduction in external Na + , application of nifedipine at concentrations below 300 nM or substitution of external Ca 2+ with Ba 2+ , but was reduced by Ni 2+ with an ED50 of 6 ± 1 mM. When cells were stepped from _100 to _30 mV in Ca 2+ -free conditions, small inward currents could be detected. These were enhanced 40-fold in divalent-cation-free solution and blocked in a concentration-dependent manner by Mg 2+ with an ED50 of 32 ± 16 mM. These data support the idea that human urethral myocytes possess currents with electrophysiological and pharmacological properties typical of T- and L-type Ca 2+ currents.
Collections Ireland -> Dundalk IT -> Subject = Science
Ireland -> Dundalk IT -> Open Access DRIVERset
Ireland -> Dundalk IT -> Status = Published
Ireland -> Dundalk IT -> Type = Article

Full list of authors on original publication

Keith D. Thornbury, Noel G McHale, P.F. Keane, I.K. Walsh, Siobhan M. Woolsey, Mark A Hollywood

Experts in our system

1
Keith D. Thornbury
Dundalk IT
Total Publications: 27
 
2
Noel G McHale
Dundalk IT
Total Publications: 35
 
3
Mark A Hollywood
Dundalk IT
Total Publications: 35