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Adrenergic regulation of the intracellular [Ca 2+ ] and voltage‐operated Ca 2+ channel currents in the rat prostate neuroendocrine cells
Author(s) -
Kim Jun Hee,
Shin Sun Young,
Nam Joo Hyun,
Hong EunKyung,
Chung YoungShin,
Jeong Jeong Yun,
Kang Jeongyoon,
Uhm DaeYong,
Kim Sung Joon
Publication year - 2003
Publication title -
the prostate
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.295
H-Index - 123
eISSN - 1097-0045
pISSN - 0270-4137
DOI - 10.1002/pros.10277
Subject(s) - endocrinology , medicine , pertussis toxin , fura 2 , agonist , chemistry , patch clamp , intracellular , cytosol , stimulation , voltage clamp , receptor , biology , g protein , biochemistry , electrophysiology , enzyme
BACKGROUND The prostate gland contains numerous neuroendocrine cells (PNECs) innervated by adrenergic neurons. PNECs are believed to influence the growth and physiological function of the prostate gland via paracrine release of hormones. MATERIALS AND METHODS Using fura‐2 fluorescence measurement and patch‐clamp techniques, we investigated the effects of adrenergic stimulation on cytosolic concentration of Ca 2+ ([Ca 2+ ] c ) and high voltage‐activated Ca 2+ channel currents (HVA‐I Ca ) of the putative rat prostate neuroendocrine cells (RPNECs) freshly isolated by an enzymic digestion. RESULTS Noradrenaline (NA, 1 μM) induced a sharp, transient increase of [Ca 2+ ] c measured by the fura‐2 fluorescence. Pharmacological studies showed that α1‐adrenoceptors (α1‐ARs) coupled with PLC/IP 3 signaling pathway induce the release of stored Ca 2+ , which subsequently recruits store‐operated Ca 2+ entry pathways. In the whole‐cell voltage clamp experiment, NA decreased the amplitude of HVA‐I Ca by 40%, which was mimicked by an α2‐AR agonist (UK14304) but not by an α1‐AR agonist (phenyleprine). After selective blockade of N‐type Ca 2+ channels by ω‐conotoxin GVIA, the addition of NA showed no further inhibition on the remaining L‐type Ca 2+ channel currents. The adrenergic inhibition of HVA‐I Ca was partially prevented by the pretreatment with pertussis toxin (PTX) (5 μg/ml, 4 hr, 37°C). CONCLUSIONS RPNECs express both α1‐ and α2‐ARs, signaling the release of stored Ca 2+ and the inhibition of N‐type Ca 2+ channels, respectively. Prostate 57: 99–110, 2003. © 2003 Wiley‐Liss, Inc.