FIGURE 10.

Starvation enhances the epithelial barrier function of filter-grown MDCK II monolayers. A, filter-grown MDCK II monolayers, when incubated in starvation medium, show an increase in TER over the normally fed control group (*, p < 0.01). B, starvation changed TJ ion selectivity and reduced the ratio of the permeability of Na⁺ to Cl⁻, as calculated from the dilution potentials and the Goldman-Hodgkin-Katz equation, detailed under “Experimental Procedures” (*, p < 0.001 versus control). C and D, starvation reduced the flux of small solute urea (molecular radius, 2.9 Å) (C; *, p < 0.01 versus control) but did not affect the paracellular flux of inulin (molecular radius, 15 Å, D) (flux measured after 96 h of starvation).