Characterization of Paracellular Permeability in Cultured Human Cervical Epithelium: Regulation by Extracellular Adenosine Triphosphate

OBJECTIVE: The purpose of the present study was to compare the permeability and regulation of paracellular transport in human cervical cells with those in epithelial cells of other organs. METHODS: Cervical cells (ECE16-1, Caski, and HT3) were grown on filters, and trans- epithelial electrical conductance (GT) and the permeability to pyranine (P_Pyr) were determined. RESULTS: Cervical cultures were characterized by high G_T(83-125 mS · cm^-2) and high P_Pyr(6.2-18 · 10^-6. sec^-1). The G_Twas not significantly affected by cell density but was increased by 20% by lowering extracellular calcium to 0.45 mmol/L or less. The high values of GT and P_Pyrand the regulation by extracellular calcium indicate that all three cervical cell lines have “leaky” tight junctional complexes. Addition of extracellular adenosine triphosphate (A TP) at 50 μmol/L to the cervical cultures evoked a biphasic change in G_Tthat was unique to the cervical cells: an initial increase, followed by a sustained decrease by 30% from baseline G_T. The decrease of G_Twas associated with a decrease in P_Pyrby 17%, indicating that A TP had an effect on the tight junctional/paracellular permeability. The A TP effect was reversible either by washing or by chemical hydrolysis with A TPase. The non-cervical cell lines all responded to extracellular A TP with a transient increase in G_T, but not with the pronounced decrease. CONCLUSION: The permeability of the paracellular pathway can be regulated in cervical epithelia by mechanisms that may be different from those in epithelial cells from other organs. (J Soc Gynecol Invest 1994;1:225-33).