Dexamethasone enhances calcium-activated potassium  channel expression in blood-brain tumor barrier in a rat brain  tumor model.
This study was performed to determine whether dexamethasone (DEX) had an effect on calcium-activated potassium channels (KCa channels) in blood-brain tumor barrier (BTB).Using a rat brain glioma model, we found that the expression of KCa channels protein was significantly increased in brain tumor tissue. And bradykinin-induced increase of KCa channels protein was further enhanced after DEX pretreatment for 3 days. In addition, DEX pretreatment enhanced bradykinin-mediated up-regulation of the density of IKCa in the rat brain C6 cells in vitro BTB. Bradykinin markedly increased BTB permeability independent of DEX pretreatment. All of these results strongly suggest that DEX could regulate the target in the transcellular pathway of BTB-KCa channels.
Gu
Yan-ting
YT
Department of Neurobiology, College Basic of medicine, China medical University, Shenyang, 110001, Liaoning Province, PR China.
Xue
Yi-xue
YX
Wang
Ping
P
Zhang
Hua
H
Qin
Li-juan
LJ
Liu
Li-bo
LB
D000818:Animals; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology*; D001812:Blood-Brain Barrier / Q000187:drug effects* / Q000378:metabolism; D001920:Bradykinin / Q000494:pharmacology; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D001932:Brain Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D002199:Capillary Permeability; D045744:Cell Line, Tumor; D002491:Central Nervous System Agents / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology*; D004195:Disease Models, Animal; D005260:Female; D005910:Glioma / Q000188:drug therapy / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects; D009368:Neoplasm Transplantation; D024681:Potassium Channels, Calcium-Activated / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D015854:Up-Regulation / Q000187:drug effects
D018931:Antineoplastic Agents, Hormonal; D002491:Central Nervous System Agents; D024681:Potassium Channels, Calcium-Activated; D003907:Dexamethasone; D001920:Bradykinin