Effects of Noradrenaline on the Membrane Potential of Prostatic Neuroendocrine Cells of Rat
The Korean Journal of Physiology and Pharmacology
;
: 47-52, 2003.
Article
in English
| WPRIM
| ID: wpr-727620
ABSTRACT
The prostate gland contains numerous neuroendocrine cells that are believed to influence the function of the prostate gland. Our recent study demonstrated the expression of both alpha 1- and alpha 2-ARs, signaling the release of stored Ca2+ and the inhibition of N-type Ca2+ channels, respectively, in rat prostate neuroendocrine cells (RPNECs). In this study, the effects of NA on the resting membrane potential (RMP) of RPNECs were investigated using a whole-cell patch clamp method. Fresh RPNECs were dissociated from the ventral lobe of rat prostate and identified from its characteristic shape; round or oval shape with dark cytoplasm. Under zero-current clamp conditions with KCl pipette solution, the resting membrane potential (RMP) of RPNECs was between 35 mV and 85 mV. In those RPNECs with relatively hyperpolarized RMP ( 45 mV) showed a transient hyperpolarization and subsequent fluctuation at around 40 mV on application of NA. Under voltage clamp conditions (holding voltage, 40 mV) with CsCl pipette solution, NA evoked a slight inward current (< 20 pA). NA induced a sharp increase of cytosolic Ca2+ concentration ([Ca2+]c), measured by the fura-2 fluorescence, and the voltage clamp study showed the presence of charybdotoxin-sensitive Ca2+ -activated K+ currents. In summary, adrenergic stimulation induced either depolarization or hyperpolarization of RPNECs, depending on the initial level of RMP. The inward current evoked by NA and the Ca2+ -activated K+ current might partly explain the depolarization and hyperpolarization, respectively.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Prostate
/
Norepinephrine
/
Fura-2
/
Cytoplasm
/
Cytosol
/
Neuroendocrine Cells
/
Fluorescence
/
Membrane Potentials
/
Membranes
Type of study:
Prognostic study
Limits:
Animals
Language:
English
Journal:
The Korean Journal of Physiology and Pharmacology
Year:
2003
Type:
Article
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