title: Effects of estradiol on voltage-gated sodium channels in mouse dorsal root ganglion neurons.
abstract: Estrogen has multiple actions in the brain to modulate homeostasis, synaptic plasticity, neuroprotection and pain sensitivity. Previous studies have demonstrated that estradiol may affect the ion channel function. The role of voltage-gated sodium channels in the transmission of nociceptive and neuropathic pain messages is well-established. Herein, we report the effects of estradiol (E2) on TTX-sensitive (TTX-S) and TTX-resistant (TTX-R) Na(+) currents, using a conventional whole-cell patch clamp technique from acutely isolated mouse dorsal root ganglion neurons. We found that the extracellularly 17β-E2 inhibited TTX-S Na(+) currents and TTX-R Na(+) currents; the effects were rapid, reversible and in a concentration-dependent manner. Moreover, 17β-E2 did not significantly affect the activation curve for Na(+) channel, and shifted the steady-state inactivation curve for TTX-S and TTX-R Na(+) channels in the hyperpolarizing direction. We also found that the membrane impermeable E2-BSA was as efficacious as 17β-E2, whereas 17α-E2 had no effect. Blockers of PKC (GÖ-6983) and PKA (H-89) abrogated these acute effects of 17β-E2. In conclusion, E2 inhibited voltage-gated Na(+) channels in mouse DRG neurons through a membrane ER-activated PKC-PKA signaling pathway. Through the modulation of voltage-gated sodium currents, estradiol could affect cell excitability, firing properties.
authors.affiliation: Department of Preventive Medicine, School of Medical Science and Laboratory Medicine, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.forename: Jie
authors.initials: J
authors.lastname: Cao
authors.forename: Fang
authors.initials: F
authors.lastname: Hu
authors.forename: Rongzhu
authors.initials: R
authors.lastname: Lu
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Haixia
authors.initials: H
authors.lastname: Ding
authors.forename: Rong
authors.initials: R
authors.lastname: Gao
authors.forename: Hang
authors.initials: H
authors.lastname: Xiao
mesh_terms: D000418:Albumins / Q000494:pharmacology; D000818:Animals; D055592:Biophysical Phenomena / Q000187:drug effects*; D001703:Biophysics; D004347:Drug Interactions; D004558:Electric Stimulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology*; D008564:Membrane Potentials / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000145:classification / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D026902:Potassium Channel Blockers / Q000494:pharmacology; D026941:Sodium Channel Blockers / Q000494:pharmacology; D019789:Tetraethylammonium / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D061566:Voltage-Gated Sodium Channels / Q000378:metabolism*
chemical_list: D000418:Albumins; D004791:Enzyme Inhibitors; D026902:Potassium Channel Blockers; D026941:Sodium Channel Blockers; D061566:Voltage-Gated Sodium Channels; D013779:Tetrodotoxin; D004958:Estradiol; D019789:Tetraethylammonium