CLDN5 and Hypertension: Fragas et al. (2021), analyzing changes in caveolin-1 expression within hypothalamus of the SHRs, showed increased transcytosis and a positive effect of exercise training on normalization of this type of endothelial transport (Fragas et al., 2021). The recent studies showed an increase in transcellular transport and a reduction in claudin-5 expression in the two-kidney, one-clip model of hypertension (Perego et al., 2025).