Referenced in: none

Automatically associated channels: Kir6.2

Title: Bradykinin-induced blood-brain tumor barrier permeability increase is mediated by adenosine 5'-triphosphate-sensitive potassium channel.

Authors: Hua Zhang, Yan Ting Gu, Yi Xue Xue

Journal, date & volume: Brain Res., 2007 May 4 , 1144, 33-41

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/17331483

Abstract
Bradykinin has been shown to selectively transiently increase the permeability of the blood-brain barrier (BBB). This study was performed to determine whether ATP-sensitive potassium (K(ATP)) channels mediate the increase in permeability of brain tumor microvessels induced by BK. Using a rat brain glioma (C6) model, we found increased expression of K(ATP) channels at tumor sites via Western blot analysis, after intracarotid infusion of bradykinin at a dose of 10 microg/kg/min for 15 min. A significant increase (73.58%) of the integrated density value (IDV) of the K(ATP) channel Kir6.2 subunit was observed in rats with glioma after 10 min of bradykinin perfusion. The over-expression of K(ATP) channels with bradykinin was significantly attenuated by the K(ATP) channel antagonist glibenclamide. Immunohistochemistry and immunolocalization experiments showed that the over-expression of K(ATP) channels was more obvious near tumor capillaries of 10 microm in diameter. I(KATP) modulation by bradykinin in cultured C6 cells was also studied using the patch-clamp technique in a whole-cell configuration. Administration of bradykinin led to a significant opening of K(ATP) channels in a time-dependent manner. This led to the conclusion that the bradykinin-mediated BBB permeability increase is due to accelerated formation of K(ATP) channels, which are thus as an important target in the biochemical regulation of this process.