Effects of noradrenaline on the membrane potential of prostatic neuroendocrine cells of rat

Jun Hee Kim, Sun Yong Shin, Dae Yong Uhm, Sung Joon Kim

Research output: Contribution to journalArticle

1 Scopus citations

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 α1- and α2-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 (< -60 mV), the application of noradrenaline (NA, 1μM) depolarized the membrane to around -40 mV. In contrast, the RPNECs with relatively depolarized 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.

Original languageEnglish (US)
Pages (from-to)47-52
Number of pages6
JournalKorean Journal of Physiology and Pharmacology
Volume7
Issue number1
StatePublished - Feb 1 2003
Externally publishedYes

Keywords

  • Membrane potential
  • Neuroendocrine cell
  • Noradrenaline
  • Patch clamp
  • Prostate

ASJC Scopus subject areas

  • Physiology
  • Pharmacology

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