Fig. 5.

Luminal permeability may impact junctional stability. (A) Cross-section of an AQP0 junction, showing two monomers per tetramer. (Inset) Two fiber cells with two junctions. The pressure difference across the entire channel is ΔP = P₁ − P₂ where P₁ and P₂ are the pressures in the two cells and P₁ ≥ P₂ (see SI Appendix). The finite cavity permeability causes a pressure difference of ΔP_cav = P_1,cav − P_2,cav within the cavity. (B) Normalized cavity pressure difference ΔP_cav/ΔP and the maximum cavity pressure P_1,cav plotted as a function of the ratio of cavity to luminal permeabilities. Experimental p_f values (in 10⁻¹⁵ cm³·s⁻¹) for aquaporins 0–5 are listed (9).