Coriaria lactone increased the intracellular level of calcium through the voltage-gated calcium channels in rat hippocampal neurons.
To investigate the effects of Coriaria Lactone (CL), an epileptogenic substance, on intracellular levels of calcium ([Ca(2+)](i)) and physiological properties of voltage-gated calcium channels (VGCCs). Ratiometric calcium imaging using Fura Red and whole-cell voltage patch-clamp technique were explored on freshly isolated rat hippocampal neurons exposed to CL. Coriaria Lactone increased [Ca(2+)](i) from 118 +/- 21 to 440 +/- 35 nM; VGCCs and calcium influx through NMDA receptor served as the main routes of entry. Coriaria Lactone could enhance both Low voltage activated (LVA) and High voltage activated calcium currents in a concentration-dependent way, and its effect on LVA current was more potent (about 60%). The increased calcium currents were accompanied by the shift of voltage-dependent steady-state inactivation to more positive potentials. These effects of CL, especially its impact on LVA current, could activate different calcium-dependent signaling pathways, and influence cellular excitable properties as well, which might play an important role in CL's epileptogenic process.
Zhang
Qin
Q
Department of Neurology, West China Hospital, Sichuan University, 610041, Chengdu, Sichuan, People's Republic of China.
Lai
Xiaohui
X
Liao
Daqing
D
Stefan
Hermann
H
Zhou
Dong
D
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D019256:Cadmium Chloride / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D015640:Ion Channel Gating / Q000187:drug effects; D007783:Lactones / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D007783:Lactones; D016291:Dizocilpine Maleate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; C049836:coriaria lactone; D019256:Cadmium Chloride; D002118:Calcium