Figure 1. Ang II hypertension enhances BBB permeability.
A. Slow-pressor Ang II increases systolic BP gradually (n=10; 2-way ANOVA, Bonferroni’s multiple comparisons test; *p<0.001). B. Ang II hypertension enhances BBB permeability to 3kDa FITC-dextran (n=13-14; two-tailed unpaired t-test, *p<0.0001 vs saline). C. Ten minutes following 3kDa FITC-dextran administration, BBB leakage is visualized by 2-photon microscopy. Scale bar: 100μm. D. In cerebral microvascular preparation Ang II hypertension reduces the mRNA expression of the TJ proteins claudin-5 and occludin, but not ZO-1 (n=7-8). Expression of the vesicular transport regulator Mfsd2a is also suppressed (two-tailed unpaired t-test, claudin-5 n=10-12 *p=0.0275, occludin n=11-16 *p<0.0001, Mfsd2a n=11-12 *p=0.0002). E. In cerebral endothelial cell cultures, Ang II treatment (300nM; 24 hours) disrupts TJ as reflected by claudin-5 (green) internalization and ZO-1 (magenta) disorganization. Scale bar: 50μm. Abbreviations: A: arteriole; V: venule; SBP: systolic blood pressure.