One cause of high blood pressure may lie within the brain rather than the heart or blood vessels, according to recent studies by scientists at the University of Bristol, in England, and the Fukushima Medical University School of Medicine, in Japan (Waki H et al. Hypertension. doi:10.1161/HYPTERTENSIONAHA.106 .085589 [published online ahead of print April 9, 2007]).
The investigators previously showed that a protein called junctional adhesion molecule-1 (JAM-1), which forms tight junctions between adjacent endothelial cells and is part of the blood-brain barrier, is differentially expressed in the brain stem of spontaneously hypertensive rats compared with normotensive animals. JAM-1 also plays a role in trapping leukocytes and causing inflammation, which may obstruct blood flow.
Hampton T. Blood Pressure and the Brain. JAMA. 2007;297(21):2339. doi:10.1001/jama.297.21.2339-d